tag:blogger.com,1999:blog-41842500091822419722024-03-16T15:08:17.393-05:00CQ CQ CQ de W0VLZThis is a blog about my ham radio experiences including vintage homebrew, QRP operating and the National Radio company.Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.comBlogger231125tag:blogger.com,1999:blog-4184250009182241972.post-57223726834300022202024-02-21T17:17:00.006-06:002024-02-22T07:15:55.210-06:00WN6ULH / WA5VLZ / W0VLZ Through the Years<p> Here is a look at my stations through the years: <a href="http://wiegandfamily.org/shack_tours/shacks.html" target="_blank">http://wiegandfamily.org/shack_tours/shacks.html</a><br /></p>Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-54432011360922665702024-01-07T16:42:00.001-06:002024-01-07T16:42:52.329-06:00<p> Some entries on this blog link to information on prismnet.com may be broken. If so, try going to https://web.archive.org/web/20220604005204/https://www.prismnet.com/~nielw/wa5vlz.htm<br /></p>Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-18724394255856949802024-01-04T12:03:00.014-06:002024-01-06T14:44:38.071-06:00QRPKits / Pacific Antenna 40 mtr EZRcvr<p>Looking over my shack I see a lot of two tube homebrew receivers, mostly regeneratives. It's time for a two IC receiver. </p><p> I've been a fan of direct conversion receivers for some time. Unfortunately most of them have left the market but recently my search found the <a href="https://www.qrpkits.com/ezreceiver.html" target="_blank">QRPKits / Pacific Antenna 40 mtr Easy Rcvr</a>. While only covering 75KHz of 40 meters the $25 price tag made it sound interesting. If I don't actually use it on the air maybe I can recommend it to a friend of mine as a learning tool and cheap way to listen in to ham QSOs.</p><p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtKNKLHql09X6SdcL4XqKpRyacYJq0ffFvajFQwPXthpzqMxkpywwfQ-b3VnO0WT7dNkNStSMHcxco8EFVe79u65HIj0s0fbVwX3kp8BYKvehlIEZw5SX6RtdUooYiV-OLKOuCXbw544u_UKnNbdj8ah3Fn930f9rvAogpa-4iX_3HOEwgJITUWxwjZHpU/s602/EZReceiverAsReceived2.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="508" data-original-width="602" height="169" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtKNKLHql09X6SdcL4XqKpRyacYJq0ffFvajFQwPXthpzqMxkpywwfQ-b3VnO0WT7dNkNStSMHcxco8EFVe79u65HIj0s0fbVwX3kp8BYKvehlIEZw5SX6RtdUooYiV-OLKOuCXbw544u_UKnNbdj8ah3Fn930f9rvAogpa-4iX_3HOEwgJITUWxwjZHpU/w200-h169/EZReceiverAsReceived2.jpg" width="200" /></a></div>My $25 (plus tax and shipping) got me a small plastic bag with all of the parts plus knobs, antenna connector and a 9V battery connector. A battery, antenna and ear phones/buds were all that was needed to put it to use. <div class="separator" style="clear: both; text-align: left;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhK0R0_DB3SL2iiuip17AzoODO6HiBB_DqtlArQhm_AhHD3F6x4ovhGOsUURi2TyiqJnz_ZqG10vbGPvnekDqtzYk0p2Eq4Sg4SM38PnF1G-Wos_WTS6IGcXnCyf7bx9Z5kkrpUmwB422HaRDqiRQH6VJLVunQ1wCJqZa_SpgwL2gkrgE_08jifmIV4rKnC/s4000/StepByStep.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="4000" data-original-width="3000" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhK0R0_DB3SL2iiuip17AzoODO6HiBB_DqtlArQhm_AhHD3F6x4ovhGOsUURi2TyiqJnz_ZqG10vbGPvnekDqtzYk0p2Eq4Sg4SM38PnF1G-Wos_WTS6IGcXnCyf7bx9Z5kkrpUmwB422HaRDqiRQH6VJLVunQ1wCJqZa_SpgwL2gkrgE_08jifmIV4rKnC/w150-h200/StepByStep.jpg" width="150" /></a></div>I really liked the available on-line manual. It had check-off steps taking you though construction component by component along with construction tips and a troubleshooting guide. It reminded me of some of the Heathkit projects I've built in the long past.</div><div class="separator" style="clear: both; text-align: left;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjF8XGcDd5Cokt72vIYqVltOZjBJf9pZ0185v87PIpCU3U9pvgIfVjVAcV8YMKiXzP1t5Vdu2ws-t_-TpkOPykeP0VOpxmDeRrKBxm7FDGdc763ndbUS8Vd6BNnzaaaYdR52UOkBgCIuO7s-wlbeHNL52VJt4zlvZ1z-GvxMlsagMs4rJF6nmQ8G3vdVJv4/s1779/EZRcvrSortedParts3.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="830" data-original-width="1779" height="93" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjF8XGcDd5Cokt72vIYqVltOZjBJf9pZ0185v87PIpCU3U9pvgIfVjVAcV8YMKiXzP1t5Vdu2ws-t_-TpkOPykeP0VOpxmDeRrKBxm7FDGdc763ndbUS8Vd6BNnzaaaYdR52UOkBgCIuO7s-wlbeHNL52VJt4zlvZ1z-GvxMlsagMs4rJF6nmQ8G3vdVJv4/w200-h93/EZRcvrSortedParts3.jpg" width="200" /></a></div>The first step was to inventory the parts. Many of the parts, while discrete pin-in-hole, are really small. In some cases I had to use my phone's camera to blow up part markings in order to read them. I also made use of my digital multimeter to confirm what I was reading.</div><div class="separator" style="clear: both; text-align: left;"> </div><div class="separator" style="clear: both; text-align: left;">While an "Easy" receiver, this one still takes care in building. The component locations are all clearly marked but the solder pads are pretty close together in order to all fit on the 3.5" x 2" printed circuit board. I needed to get a sharper tip for my solder iron before I felt I could do a good job without any solder bridges. On the plus side the solder mask was effective. </div><div class="separator" style="clear: both; text-align: left;"> </div><div class="separator" style="clear: both; text-align: left;"> </div><div class="separator" style="clear: both; text-align: left;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEil48k5xGSR9xcGEAehlGBBv5krRShf1WFx1s3lT0dcyXwfO_7YT3L58Q6M0ERWdHSUgkY5Rz7-qm0vCujEyXHCvQrP95UCaHuRaxPP9dqKcVDwQxLfe0CRhDSmpREcEHQgOLx4-LKf8INs6-H2SNc3jQFLwTTL-vjNjaB0qxFMUx2iMB-s5nfDMM_xNMXY/s1600/EZRcvrAssembled.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1600" data-original-width="1200" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEil48k5xGSR9xcGEAehlGBBv5krRShf1WFx1s3lT0dcyXwfO_7YT3L58Q6M0ERWdHSUgkY5Rz7-qm0vCujEyXHCvQrP95UCaHuRaxPP9dqKcVDwQxLfe0CRhDSmpREcEHQgOLx4-LKf8INs6-H2SNc3jQFLwTTL-vjNjaB0qxFMUx2iMB-s5nfDMM_xNMXY/w150-h200/EZRcvrAssembled.jpg" width="150" /></a></div>My Easy Receiver worked when I first powered it up. All I needed to do was set which part of 40 mtrs I wanted to cover. While marketed as half of a QRP CW station I found it works fine as a SSB phone receiver, not as good as a modern transceiver but certainly usable. </div><div class="separator" style="clear: both; text-align: left;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjr-q7b360iZSVze_A-zbgLTvHjeh0lWkgyolFhgRb3ZX08mec1HJO4cRYbz2S5RRwn78T54zryXhCB1nUa32_rgLMeg4j750uhasykCLjCeomPE9UGZRkIu6QHvvg94ZMPbkRBmb8Ieb7mPPxy7-aAyXJ6Jncpyiw2my6iZa896m2zs2V7j1f8Bv9UAdgt/s810/EZRcvrFront.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="569" data-original-width="810" height="141" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjr-q7b360iZSVze_A-zbgLTvHjeh0lWkgyolFhgRb3ZX08mec1HJO4cRYbz2S5RRwn78T54zryXhCB1nUa32_rgLMeg4j750uhasykCLjCeomPE9UGZRkIu6QHvvg94ZMPbkRBmb8Ieb7mPPxy7-aAyXJ6Jncpyiw2my6iZa896m2zs2V7j1f8Bv9UAdgt/w200-h141/EZRcvrFront.jpg" width="200" /></a></div>The final Easy Receiver packaging is left up to the creativity of the builder. The QRPKits website mentions stacking it with the matching transmitter for a complete 40 mtr QRP station. For now I wanted more of a stand-alone receiver for listening to SSB.</div><div class="separator" style="clear: both; text-align: left;"><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsX1MV_E2gTSRlCoRt9Ip0k_1BxG2QP5pEcDjQp3mKI9t255dT9bULaZ-BRYb86cjXjVc2T3VZRf0S6mvdUZGsccFf0yeg1rJ6ldJDdljYGMLj1IK34uCgyj52Ia1CfVqZJcA9ESiAXO_6eUyiG-CpAqrwYCJCDFrOKRBbyXEkIVtu0-2UXyCLrnxtgrND/s1011/EZRcvrBack.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="1011" data-original-width="1006" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjsX1MV_E2gTSRlCoRt9Ip0k_1BxG2QP5pEcDjQp3mKI9t255dT9bULaZ-BRYb86cjXjVc2T3VZRf0S6mvdUZGsccFf0yeg1rJ6ldJDdljYGMLj1IK34uCgyj52Ia1CfVqZJcA9ESiAXO_6eUyiG-CpAqrwYCJCDFrOKRBbyXEkIVtu0-2UXyCLrnxtgrND/w199-h200/EZRcvrBack.jpg" width="199" /></a></div>For the "enclosure" I used a scrap of 4x1 as the base with a piece of aluminum attached to it for the front panel. Next, the stock Easy Receiver comes with no power switch. I added one to avoid wear and tear on the 9V battery connector. I also changed out the small knobs provided by QRPKits in order to make it easier to tune SSB signals. Finally, I added a more generic antenna connection. I wish I could have added some sort of bandspread, vernier tuning or a 10 turn pot as suggested by QRPKits. As it is now tuning SSB takes patience and a steady hand.</div><div class="separator" style="clear: both; text-align: left;"> </div><div class="separator" style="clear: both; text-align: left;">I've uploaded a demo to you tube. View it <a href="https://youtu.be/QdOpQO1sk6A" target="_blank">here</a>.<br /></div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;">I'm pretty happy with my 40 mtr Easy Receiver. It makes a good loaner that allows someone to get a feel for ham radio. It is also easy to shift down to the CW band so that I can pair it with a similar transmitter and head for a park. <br /></div><div class="separator" style="clear: both; text-align: left;"><br /></div><div class="separator" style="clear: both; text-align: left;"><br /></div><p></p><p><br /></p><p><br /></p><br /><p><br /></p><br /><br />Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-64507675820944625392023-12-29T12:29:00.004-06:002024-01-25T07:50:15.514-06:00National Radio Product Listing I have a listing of ham radio products introduced by the National Radio Company. Each entry is linked to a catalog style description of the item. Click <a href="https://www.wiegandfamily.org/nat_list/nat_list.htm">here</a> to view it.<br />Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-31206748441963807812022-04-09T13:59:00.015-05:002024-01-01T22:06:44.802-06:00Summer QRP => Portable Antennas<p></p>
<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOmakTzEewlXeXAQof6M47rcRRagErtIXc1WitlWSZnH8FC9Mqm6WWHodHjkzG9x1KXbu5zBHBckpGkmiQ8xa8Qh2ofCGw_1BQqt1iFN6VJ2WDiPC6ImsDUzvmlcpxV-66Y8SKLsopKvtiScdk7EjSbRtNjH8pMUiMACj0rwiqW4jqb75G74M6casoMQ/s600/CraterLake_july04.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="417" data-original-width="600" height="139" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjOmakTzEewlXeXAQof6M47rcRRagErtIXc1WitlWSZnH8FC9Mqm6WWHodHjkzG9x1KXbu5zBHBckpGkmiQ8xa8Qh2ofCGw_1BQqt1iFN6VJ2WDiPC6ImsDUzvmlcpxV-66Y8SKLsopKvtiScdk7EjSbRtNjH8pMUiMACj0rwiqW4jqb75G74M6casoMQ/w200-h139/CraterLake_july04.jpg" width="200" /></a>
</div>
Summertime is QRPxpedition time here at W0VLZ. After a winter of playing with
boat anchors in the basement I'm ready to get out to a park with my KX3. With
any rig I always have to think about an antenna. Looking back on my blog and
website I see that I've gone through this before.
<p></p>
<p>Here are some links: </p>
<p>
<a href="https://w0vlz.blogspot.com/search/label/20%20Mtr%20Zepp">https://w0vlz.blogspot.com/search/label/20%20Mtr%20Zepp</a>
Construction details and experiences using a 20 meter endfed halfwave wire
"tuned" by 14' of TV twinlead.
</p>
<p>
<a href="https://w0vlz.blogspot.com/search/label/20%20Mtr%20Crappie%20Pole%20Vertical">https://w0vlz.blogspot.com/search/label/20%20Mtr%20Crappie%20Pole%20Vertical</a>
A portable 20 meter vertical
</p>
<p>
<a href="https://w0vlz.blogspot.com/search/label/20%20Mtr%20C-Pole">https://w0vlz.blogspot.com/search/label/20%20Mtr%20C-Pole</a>
Building and using a C-Pole Vertical
</p>
<p>
<a href="https://www.wiegandfamily.org/CrappiePoleAntenna/CrappiePolesPP.pdf">https://www.wiegandfamily.org/CrappiePoleAntenna/CrappiePolesPP.pdf</a>
My quest for a stand-alone 20 mtr portable antenna
</p>
<p>
<a href="https://w0vlz.blogspot.com/search/label/30-10%20Mtr%20Clotheline%20Dipole">https://w0vlz.blogspot.com/search/label/30-10%20Mtr%20Clotheline%20Dipole</a>
A 30-10 meter "clothes line" dipole
</p>
<p>See you next time from a convenient park.</p>
<p>73, Niel - W0VLZ<br /></p>
<p><br /></p>
<p> </p>
<p> </p>
Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-68436949611060453112022-03-31T15:57:00.001-05:002022-03-31T22:13:16.589-05:00A Shack Tour<p>This past winter I finished setting up my new ham shack. It has 10 operating positions but (reflecting my ham radio interest in vintage technology) only <a href="https://w0vlz.blogspot.com/2021/09/on-air-again.html">one antenna.</a></p><p>See it on YouTube at <a href="https://www.youtube.com/watch?v=Q7C7-a1hN70">https://www.youtube.com/watch?v=Q7C7-a1hN70</a> <br /></p>Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-14256679241847395872022-03-25T22:11:00.009-05:002023-12-29T16:05:45.416-06:00Building and Using a Push-Pull TNT Transmitter<p></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyvTxPBZIbUs8_Nj4Gb4iBUYvulAbl0-CWPECaNsZhURt_JPA2CCFlBpRb5JFPTrhaWvBPK8A94dL4ckIA9703M7smB9MOs-5QEKapItsZo1Z3bnzGYyKOEyLAHAKVi0GMAOGmz9jM6oVE0J5ZBRspTG-VCKolQWdtXa1Ue35NvCrscODERPnLkw0UWYAa/s490/tntschm.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="275" data-original-width="490" height="113" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhyvTxPBZIbUs8_Nj4Gb4iBUYvulAbl0-CWPECaNsZhURt_JPA2CCFlBpRb5JFPTrhaWvBPK8A94dL4ckIA9703M7smB9MOs-5QEKapItsZo1Z3bnzGYyKOEyLAHAKVi0GMAOGmz9jM6oVE0J5ZBRspTG-VCKolQWdtXa1Ue35NvCrscODERPnLkw0UWYAa/w200-h113/tntschm.jpg" width="200" /></a></div><br />My first '29 transmitter was a push-pull TNT. I built this transmitter in 1989 based on an article in the Nov 1930 issue of QST. I have web pages about this transmitter but those pre-date this blog. Here are links to those pages: <p></p><p>- A 1930 TNT transmitter: <a href="https://www.wiegandfamily.org/tnt/tnt.htm">http://www.wiegandfamily.org/tnt/tnt.htm</a></p><p>- Operating a late 20s/early 30s ham station: <a href="http://www.wiegandfamily.org/1929Stn/1929Station.htm">http://www.wiegandfamily.org/1929Stn/1929Station.htm</a></p>Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-6620162340222610712022-03-18T10:45:00.005-05:002022-03-19T11:49:44.214-05:00Winter 2022 Vintage Radio<div class="separator" style="clear: both;"><a href="https://blogger.googleusercontent.com/img/a/AVvXsEhqd100w_7JGwJoGY6puyDvk6o7smmGGEOf97IyKwLdZldgms7h77LtCYZh6gknnkS_FlxkSKsHGg8hO-LQp1gr73HLBBHxsqlaWwtW8zlt307twORa-n3kohpO2hHs2QVB3l6QJBKP3czNJ4zLpd-vsfyqp3Vfr1bJvbk0zF_2sEZJbvRxsXKQXwOjwg=s3286" style="clear: right; display: block; float: right; padding: 1em 0px; text-align: center;"><img alt="" border="0" data-original-height="2296" data-original-width="3286" src="https://blogger.googleusercontent.com/img/a/AVvXsEhqd100w_7JGwJoGY6puyDvk6o7smmGGEOf97IyKwLdZldgms7h77LtCYZh6gknnkS_FlxkSKsHGg8hO-LQp1gr73HLBBHxsqlaWwtW8zlt307twORa-n3kohpO2hHs2QVB3l6QJBKP3czNJ4zLpd-vsfyqp3Vfr1bJvbk0zF_2sEZJbvRxsXKQXwOjwg=s200" width="200" /></a></div>As of last Sunday my winter 2022 vintage radio season is history. Along the way I was on the air in five different events using 5 receivers and 5 transmitters. Three of these events are sponsored by the Antique Wireless Association ( <a href="https://www.antiquewireless.org/homepage/contests/">https://www.antiquewireless.org/homepage/contests/</a> ). One other, Straight Key Night, is sponsored by the ARRL ( <a href="https://www.arrl.org/straight-key-night">https://www.arrl.org/straight-key-night</a> ). The fifth was the Novice Rig Roundup ( <a href="http://www.novicerigroundup.org/">http://www.novicerigroundup.org/</a> ). These events allowed me to get comfortable with my new QTH and were low key enough that I could identify any hidden station quirks without feeling rushed or having to worry about keeping QSOs as short as possible. Each of these events was more like a saunter through the bands rather than a sprint.
<p>The Novice Rig Roundup was my favorite. Its nine day operating window let me work around stormy weather, other contests, family obligations and propagation while still having fun.
</p><p>I did find that I really like my Drake 2NT/R4B station. The 2NT operates break-in well with the R4B and its delay/timing circuit allows the crystal oscillator to run between code character elements. This minimizes chirp, even for the laziest of crystals. The R4B has KHz frequency readout and great filtering options. This pair is a keeper.
</p><p>With almost 40 years of radio technology between my '29 transmitters and the 2NT it is not surprising that my '29 station is the more unique (and challenging) to use. Challenging, though, does not mean unusable. While unique and challenging my '29 station is still usable. Depending on conditions I can switch between an SW3, an early 30s National regenerative receiver, and my early 80s Drake SPR4. Once and a while it is good to go back and experience ham radio roots.
</p><p>We've already had temperatures in the 60s this year. With spring arriving the snow has melted here in southeastern Minnesota. Now I'll start thinking about my QRP in the Park plans.</p><p></p><p></p><p></p>Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-42832646399996050062021-09-18T14:30:00.008-05:002022-01-01T11:39:49.338-06:00On The Air Again!<p> After almost a year off the air I'm finally back with a working antenna system.<br /> </p><p>Before my move I started thinking in terms of a trap vertical at the new QTH but I had safety concerns. My backyard butts up to a public golf course. For many reasons this is a great location but how can I keep a golfer from straying through the yard and, possibly, leaning against my ground mounted vertical as he is searching for a ball? A vertical would not work. I needed something up in the air.<br /><br /></p><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2Cnh2fIRfy0L7pxW8bDDH0b1BWzN96aDI-awMH_09dFCpt2GKbimOBJUv1WHlTqlRwsHqX5YvAHQkozOyjL1CuF-rpBhDd2gOJJUn0SZgYEnxUnp4X_vssfRFFiwqLEaDBc5Exv2Lrpwh/s1200/AntRadialsResized.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="807" data-original-width="1200" height="134" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi2Cnh2fIRfy0L7pxW8bDDH0b1BWzN96aDI-awMH_09dFCpt2GKbimOBJUv1WHlTqlRwsHqX5YvAHQkozOyjL1CuF-rpBhDd2gOJJUn0SZgYEnxUnp4X_vssfRFFiwqLEaDBc5Exv2Lrpwh/w200-h134/AntRadialsResized.jpg" width="200" /></a></div><br />The layout of the yard, safety and the need to keep my installation as unobtrusive as possible led me to an inverted L using insulated wire. I have almost always used some sort of end fed antenna, both for portable/QRP operation and for the main station. An inverted L would be no exception and a 66' wire would easily fit. <div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEge24oMbawh8uCBm6tjcRL6Kip-OY7LoHPdEBndUqoCmFFNhGezv8FZ7OL9h7gsyHeO6mWSt0TftJUpv6BBp96F1RJdZVtgf5PtwQMxHcopvua0qMIP7ecMAWm3KpzfSq8nw0FYzRwBgzjl/s1340/RadialHub.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="1340" data-original-width="1200" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEge24oMbawh8uCBm6tjcRL6Kip-OY7LoHPdEBndUqoCmFFNhGezv8FZ7OL9h7gsyHeO6mWSt0TftJUpv6BBp96F1RJdZVtgf5PtwQMxHcopvua0qMIP7ecMAWm3KpzfSq8nw0FYzRwBgzjl/w179-h200/RadialHub.jpg" width="179" /></a></div><br />I installed my 66' inverted L over a south facing half circle field of 22 40' radials, all terminated at a DX Engineering Radial Plate. This easily loads up on 80 and 30 but presents a very high impedance on 40, 20, 15 and 10 where it is a half wave (or voltage fed) antenna. The solution on these bands is a 49:1 wideband EFHW matching transformer. This allows the high impedance (2.5K-3K) inverted L to be transformed down to 25-100 ohms, a load my transmitter and/or antenna tuner can easily handle. <br /><br /><div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAu3SxWUF3lrDOsgO1-67XgWmaOtqrcy24_KvDWULxIenau4Dd32anMhlyHpKRFrxwNOnaTqTMk0IJIfy1SY0Y5pEldJfImJBA4l3yA4vSLG1L6pTkgqomYReIu8w_tlf8PMwmX5G926uU/s1200/transformers.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="655" data-original-width="1200" height="109" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhAu3SxWUF3lrDOsgO1-67XgWmaOtqrcy24_KvDWULxIenau4Dd32anMhlyHpKRFrxwNOnaTqTMk0IJIfy1SY0Y5pEldJfImJBA4l3yA4vSLG1L6pTkgqomYReIu8w_tlf8PMwmX5G926uU/w200-h109/transformers.jpg" width="200" /></a></div><br />My shack is just behind the radial plate/hub. I mounted the 49:1 transformer on the inside wall here. I can easily bypass this transformer for operation on 80 and 30. In addition, everything is out of the weather.<br /><br />Does it work? The Reverse Beacon Network says that my KX3 at 10 watts is covering the US on 40, 30 and 20. On 80 it appears to be working as a NVIS (Near Vertical Incidence Skywave) antenna as expected . I'll find out for certain starting in November as we move into the winter vintage radio contest season.<br /><br /><br /><p></p><br /><br /><br /><p><br /></p>Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-76162551258496429062020-11-04T08:14:00.005-06:002020-11-04T08:24:20.107-06:00A tour of W0VLZ<p> Last Sunday Phil, WE0K, stopped by. I'm lightening my load in preparation for a move and Phil was acquiring a heavy load.</p><p>While Phil was here he did a video tour of my shack including many of my vintage operating positions. You can view it at<a href="https://youtu.be/u-vH10U71qY?t=1"> https://youtu.be/u-vH10U71qY?t=1</a><br /></p>Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-6597236470205407352020-07-22T15:35:00.000-05:002020-07-26T22:37:00.813-05:00A 1929 Transmitter on 14MHzThis year the<span style="font-weight: normal;"> <a href="https://antiquewireless.org/homepage/bruce-kelley-1929-qso-party/">Bruce Kelley Memorial 1929 CW QSO Party</a></span> will include 20 meters. I decided to see how my Push-Pull Colpitts does on 14MHz. It has a fairly good note and is very usable in the BK.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT5ieEWlNHlyq3JKxbuG6SekBmUXr_aGtSMR5LhYo7JbM0XWahG1T_PW9X8FawEjCmeqNRzgf4qartq7Z8I2AoJMPWcLEypqP8z7e0jabZRbPUmPI_IEhkYlIBt8UMLnpIEj5pF-PxF4SN/s1600/20MtrCoils_IMG_4113.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="974" data-original-width="1200" height="161" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgT5ieEWlNHlyq3JKxbuG6SekBmUXr_aGtSMR5LhYo7JbM0XWahG1T_PW9X8FawEjCmeqNRzgf4qartq7Z8I2AoJMPWcLEypqP8z7e0jabZRbPUmPI_IEhkYlIBt8UMLnpIEj5pF-PxF4SN/s200/20MtrCoils_IMG_4113.jpg" width="200" /></a>I wanted to stay with a high capacity tank circuit. This minimizes RF current through the tubes and should improve tone and performance. In addition, I wanted a number of turns in the tank coil so that I would have reasonable transformer coupling between the tank coil and the antenna link. I ended up with two 4 turn, 3" long coils wound on a 1.25" form. This 1.25" form resulted in more tank coil turns on 20 compared to the 2.5" form used for the tank coils on 40 and 80 and the antenna link coils. Tank capacitance is about 100 pF on 14 MHz. My Colpitts now runs at about 20% efficiency giving 2-3 watts output on 20 meters.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhufqfEooqnmzOY5nBnnfaxOzlx3pOc9EW96BrSIo-DJ7QMg-HNJIhocxTflRs2CWxbWm_S9-Dnq5_QrH0LFpP_yxP3ZnOJyWjIF-vMdVV5kkLuIkl1e4Bq1d6TFWQyXyrrt8Ky_MlnjynS/s1600/20MtrPPColpitts_IMG_4111.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="1121" data-original-width="1200" height="186" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhufqfEooqnmzOY5nBnnfaxOzlx3pOc9EW96BrSIo-DJ7QMg-HNJIhocxTflRs2CWxbWm_S9-Dnq5_QrH0LFpP_yxP3ZnOJyWjIF-vMdVV5kkLuIkl1e4Bq1d6TFWQyXyrrt8Ky_MlnjynS/s200/20MtrPPColpitts_IMG_4111.jpg" width="200" /></a></div>
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<center>
My 14 MHz CW Signal as recorded on July 22, 2020 using the <a href="http://www.sdrutah.org/">Northern Utah WebSDR</a>:
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<audio controls=""><source src="https://www.prismnet.com/%7Enielw/PushPullColpitts/22July2020_Time19_37_52Z_14062.9kHz_PPColpitts2_5Watts.wav" type="audio/wav"></source>
</audio><br /><br />
For comparison listen to this same transmitter on 80 meters: <br /><br />
<audio controls=""><source src="https://www.prismnet.com/%7Enielw/PushPullColpitts/VE7SL_W0VLZ_3565_28Mar2019B.mp3" type="audio/mpeg"></source> </audio>
</center>
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<br />Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-39004562633621392582020-05-17T14:20:00.003-05:002020-10-02T15:35:28.682-05:00What Do I Sound Like?Have you ever gotten a 597 signal report after putting a lot of time and effort into building that new rig copied from an old (or really old) issue of QST? What is the other station hearing? More than likely they aren't familiar with the <a href="https://en.wikipedia.org/wiki/R-S-T_system#Tone">definition of a T7 signal</a> (which to many of us sounds fine). Maybe it just sounds different or maybe it has chirp or maybe it sounds like a buzz saw the morning after a big party.<br />
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The first thing I do is check my signal in the shack receiver, but lots of times I'm overloading my receiver and I sound like that buzz saw. Is this really what others are hearing? Maybe being so close makes a minor problem sound worse than it is.<br />
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The next step is to have a friend a few miles away listen to you and, possibly, hold a phone up to the speaker so that you can hear your self. This can be real helpful but lots of times I need a more complete listen.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjujKP0LTgKqjc61Pm2-Ve-CQ7pREjXLn9c9G6Ig8WhHUK1SVYuGtbyQlOqA5XpsqEJkCAHj8KXw473OoqzuPpq7c5xPRa0T9h2GmkhFvyce21JUXjsVj9zrKQwEK61axW9sMgvjKhiOLBp/s1600/K3FEF_SDR.jpg" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="871" data-original-width="1204" height="144" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjujKP0LTgKqjc61Pm2-Ve-CQ7pREjXLn9c9G6Ig8WhHUK1SVYuGtbyQlOqA5XpsqEJkCAHj8KXw473OoqzuPpq7c5xPRa0T9h2GmkhFvyce21JUXjsVj9zrKQwEK61axW9sMgvjKhiOLBp/s200/K3FEF_SDR.jpg" width="200" /></a>As a final check I recommend taking advantage of one of the many <a href="https://skywavelinux.com/best-sdrservers.html">web based radios </a>available all over the world. Link into one of these, turn on your own computer speaker, set the frequency/mode you wish to test and then transmit. Given needed propagation you can listen to yourself and the waterfall display helps you see what your signal is actually doing. <br />
<br />Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com1tag:blogger.com,1999:blog-4184250009182241972.post-20117129641725542162020-05-01T12:00:00.017-05:002021-08-25T12:04:39.623-05:00Push-Pull Colpitts Tips<p>(As questions/answers/tips concerning my Push-Pull Colpitts come up I'll post my thoughts here.)</p><p></p><p></p><p></p><p></p><p><b>How do you get this transmitter on frequency?</b> Typically I'm tuning my transmitter to a frequency I'm listening to on the station receiver. If so, I simply tune the transmitter until it is heard in the receiver. Now, a couple of things to keep in mind. First, the load on this sort of directly coupled oscillator transmitter will effect the frequency. You will have to have the transmitter connected to your antenna when setting the frequency. Try to keep this short as everyone can hear you swishing the band. Second, be careful that you are listening to your actual signal and not an image. A superhet receiver will receive two signals at the same dial setting. The second, unwanted and weaker signal, is called the image. Filtering within the receiver rejects this image signal but filtering can only do so much. The strong local signal from your transmitter may get through the receiver filtering as a weak station. If you use that as your transmit frequency, you will be far off your intended frequency and, possibly, out of band. </p><p><b>Where's the key? </b>Many early transmitter construction articles left the keying method up to the builder. Everyone had their favorite. In this case I used cathode keying by placing the key between the filament center tap and ground. Lacking a filament transformer with a center tap I could have simulated the center tap by using two 40-75 ohm resistors. Keep in mind that cathode keying results in some amount of voltage on the ungrounded key terminal. See my blog entry at <a href="https://w0vlz.blogspot.com/2018/04/cathode-keying-safety.html">https://w0vlz.blogspot.com/2018/04/cathode-keying-safety.html</a> for how to deal with this. Also, be sure to provide a separate path for B- to ground. Otherwise you will be doing B- keying and have the entire power supply voltage across your key terminals.<br />
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<b>Why are your coils different from what the article says? </b>Studying the original January 1934 QST article I decided that the 80 mtr coils were just too tightly wound for my comfort. The author allowed only 1/16" between each turn. Shorts were bound to happen. I added 1/2" to each tank coil, spacing the tank coil supports 3" apart rather than 2 1/2" apart. I had enough spare capacity in my tank capacitor to compensate for the decreased inductance. For the same reason I allowed 2 1/4" between the inner to tank coil supports rather than the specified 2". My antenna link coil has only 5 turns rather than 7 like the article recommended. I found that 5 turns gave me more output at 12-15 watts input.<b><br /></b></p><p>
<b>What are the coil sizes and turn counts?</b>
Here's what I came up with for coils for 80, 40 and 20:<br /></p><p>
</p><center>
<table border="2" cellpadding="5">
<tbody align="center">
<tr>
<td>Band</td>
<td>Coil</td>
<td>Material</td>
<td>Diameter</td>
<td># Turns</td>
</tr>
<tr>
<td>80</td>
<td>Tank</td>
<td>3/16" Cu</td>
<td>2 1/2"</td>
<td>10</td>
</tr>
<tr>
<td>80</td>
<td>Ant Link</td>
<td>3/16" Cu</td>
<td>2 1/2"</td>
<td>5</td>
</tr>
<tr>
<td>40</td>
<td>Tank</td>
<td>1/4" Cu</td>
<td>2 1/2"</td>
<td>5</td>
</tr>
<tr>
<td>40</td>
<td>Ant Link</td>
<td>1/4" Cu</td>
<td>2 1/2"</td>
<td>3</td>
</tr>
<tr>
<td>20</td>
<td>Tank</td>
<td>3/16" Cu</td>
<td>1 1/2"</td>
<td>4</td>
</tr>
<tr>
<td>20</td>
<td>Ant Link</td>
<td>3/16" Cu</td>
<td>1 1/2"</td>
<td>2</td>
</tr>
</tbody></table>
</center><p>
</p><p> Keep in mind
that there are two tank coils per band with the antenna link coil
swinging in a 2 1/4" gap between them. Each tank coil is 3" long and
each antenna link coil is 1 1/2" long. Wind all of the coils in the same
direction. I found 3/16" copper tubing on Amazon.</p><p><br />
<b>What sort of tank tuning cap is that? </b>This Push-Pull Colpitts calls for 250pf across the tank coil with the capacitor rotor grounded and the tank coil connected to the two stators. This requires each section to be 500pf. What I found is a dual 550pf per section Cardwell capacitor. It is physically laid out with the two sections, both rotor and stator, turned opposite each other. It looks like a differential capacitor but it is really just an mechanically unusual two gang variable capacitor. This design helps balance the two section rotor. Any 500-700pf per section two gang variable capacitor would work here.<br />
<br />
While we are on the topic of the tank tuning capacitor...notice that many variable capacitors have stator connections on both sides. This allows a convenient path for routing from the plate of one tube through a feedback capacitor to the grid of the other.<b><br /></b><br />
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<b>What is the order of the connections along the back?</b> See the photo below. Facing the transmitter from the outside/back, left to right: B+, B-/Gnd, Key+, Key-/Gnd, Fil CT, Fil, Fil.<br />
<b><br /></b>
<b>Will this design work with other tubes like 45s or 27s?</b> I've never tried a 27 or 45 in this circuit but others have run Push-Pull Hartley and TNT transmitters with 27s and 45s so they will probably work here. R, the bias resistor, will need to change if a different tube type is used with different characteristics. The Push-Pull TNT article in the November 1930 QST recommends a 10K bias resistor for type 10s and a 50K bias resistor for type 45s. 50K is a good starting point if planning to use 45s. <br />
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<b>What's that insulator in the center of the tank coils? </b>This insulator is there as a safety precaution. B+ is on the copper strip just below the antenna swinging link. I worried that the antenna link, if not tightly secured, might sag down and short B+ to my antenna system. This insulator limits the movement of the antenna link.<b><br /></b><br />
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<b>If I'm using 2.5V tubes like 45s or 27s do I need a 2.5 VAC filament transformer? </b>The 27 has an indirectly heated cathode. The two 27 filaments can be connected in series and lit from the 5V winding common on many tube era transformers. 45 tube filaments, while 2.5VAV, are directly heated. I don't know if they can be operated the same way. Try it and let me know.<br />
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<b>What sort of B+ supply do I use? </b>I use a regulated 200-325VDC supply. 10s can handle higher B+ but why stress them and risk an expensive tube failure? 15 watts input is fine with me. The regulated supply also results in a more stable signal.<b><br /></b><br />
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<b>The bare wiring underneath looks like it might short together. Shouldn't that all be insulated? </b>There is more room underneath the "deck" then you might guess looking at the photos. That space is 1.5" high by almost 12" x 12". There is plenty of room for three layers of wiring given stiff wire. In a few places where I needed extra stability I used brass screws as standoffs/supports.<br />
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<b>This looks pretty dangerous. Shouldn't you have a cover so you don't get electrocuted? </b>There are lots of places where B+ is exposed on this transmitter. This is not unusual for these early designs. Always shut down the power, checking it twice before doing anything behind the non-existent front panel or underneath the chassis. I also recommend leaving a metal screw driver (with insulated handle) levered between the B+ and B- power terminals while changing coils.<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhVco26sUNB0eoG01SuhjInnfe04bSFxjDucmv7H_brVRaHEqQslwNX3GLuYja1rI2L6YiVZsOLLPJZO5oPUJF_wt6cRx3fvOs4XejXU8W9CgdUvoc80Oq8XX9n_dEJenMhtQBGl7eRsnWu/s1600/QST_Schematic_Parts.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="870" data-original-width="835" height="200" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhVco26sUNB0eoG01SuhjInnfe04bSFxjDucmv7H_brVRaHEqQslwNX3GLuYja1rI2L6YiVZsOLLPJZO5oPUJF_wt6cRx3fvOs4XejXU8W9CgdUvoc80Oq8XX9n_dEJenMhtQBGl7eRsnWu/s200/QST_Schematic_Parts.jpg" width="191" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0xB2klT1-0XrHy5ctIUWDyw4F1KTkvTrDzL2P0srDnCjuECYNUIW3LxlhpTkZzRvUs7UJl0LkI2eTPnpjJwmXgosVQI9AKquC0euTskorLbYZJbf1wMIVkWp27IiD1a8vVDongS1NUjnd/s1600/IMG_3998_Bottom.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="938" data-original-width="1200" height="156" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg0xB2klT1-0XrHy5ctIUWDyw4F1KTkvTrDzL2P0srDnCjuECYNUIW3LxlhpTkZzRvUs7UJl0LkI2eTPnpjJwmXgosVQI9AKquC0euTskorLbYZJbf1wMIVkWp27IiD1a8vVDongS1NUjnd/s200/IMG_3998_Bottom.jpg" width="200" /></a><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjoxwvcUMaj2dgxfS8JVmRsXSY8taAzsIKjUOqmYiF9NxjCDXkJi6udjETFvZ0qLJlelBudo-LLOujNs6dSF1cHDXagz_dgbPdUk4hZxcv885v7OutjJ-GarYVhDhyphenhyphenuR5Aq_vDY0VTMarzB/s1600/IMG_3759C.jpg" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1489" data-original-width="1600" height="185" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjoxwvcUMaj2dgxfS8JVmRsXSY8taAzsIKjUOqmYiF9NxjCDXkJi6udjETFvZ0qLJlelBudo-LLOujNs6dSF1cHDXagz_dgbPdUk4hZxcv885v7OutjJ-GarYVhDhyphenhyphenuR5Aq_vDY0VTMarzB/s200/IMG_3759C.jpg" width="200" /></a><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRFlTXE0z7sSJ4u9-Byd5lDZuI3dq5AYo7q6vEfMYlONla54VhRqqamL8Ss48Ufafbx348Gv1NMUQJ3Z0bNjREgxgiPAx5LF5-2k_oNgBFG2tPMbHIb7hAxMP6scMn73gOon7GtW6alPEp/s1600/IMG_3753C.jpg" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="1350" data-original-width="1600" height="168" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjRFlTXE0z7sSJ4u9-Byd5lDZuI3dq5AYo7q6vEfMYlONla54VhRqqamL8Ss48Ufafbx348Gv1NMUQJ3Z0bNjREgxgiPAx5LF5-2k_oNgBFG2tPMbHIb7hAxMP6scMn73gOon7GtW6alPEp/s200/IMG_3753C.jpg" width="200" /></a></div>
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<br clear="all" /><p></p><p></p><p></p>Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com3tag:blogger.com,1999:blog-4184250009182241972.post-38302973125194183172020-02-29T11:20:00.001-06:002024-01-01T22:37:00.588-06:00A Dingey size Boat Anchor<div class="separator" style="clear: both; text-align: center;">
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I first started on this project over 15 years ago. I wanted a <a href="https://www.wiegandfamily.org/2tube_xmtr/2tube_xmtr.htm">6L6 based transmitter with a spotting function</a>. Over the years it has gone through several iterations to the "Dingey Size Boat Anchor" I use today. Along the way I added a loading control, regulated the oscillator plate voltage to 108 volts, shifted the output circuit to a pi network and repackaged it in a metal cabinet to better match my HRO Sr. Like many projects it has been a journey. Here are a few more details about this transmitter as it stands today.<br />
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The circuit itself is fairly standard using a separate 300 B+ power supply. About the only thing I don't see in most designs is SW, the spotting switch. It allows me to check my crystal frequency against any station I might want to work or against QRM. As an important serendipity it also allows me to run the oscillator continuously while keying only the 6L6 output stage. This cuts down on chirp caused by the crystal restarting at the beginning of each code element. C10, the loading capacitor, is really two capacitors in parallel. One is a typical 300pf variable. The second is a 300pf high voltage "door knob" capacitor that can be switched it/out with a toggle switch.<br />
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Coils are what I could find. The 80 and 40 meter coils are commercial Bud coils that I had. I'm using only the tank portion, not the link. For 30 I found an old plug-in coil that looked about right and tried it. It works. In general look for coils that dip and load to around 60% efficiency (ie. 6 to 7 watts output for 10 to 12 watts input).<br />
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Inside I arranged everything so that it made sense. Across the back, left to right, is the 6J5 oscillator, the 6L6 final and then the plug-in output coil. Just to the right of the coil is the toggle switch that switches in/out the additional 300pf loading capacity. The crystal socket is near the 6J5 and the 0C3 108 V voltage regulator is just to the right of that.<br />
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When changing crystals or, especially, coils it is important to recognize where high voltage is exposed. In this case the unprotected meter terminals have 300 VDC, a lethal voltage, on them. Power this transmitter down when under the covers. This is even more important when working under the chassis. Don't take chances. Power down before working on it. As a safety modification consider placing the crystal socket on the front panel.<br />
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Are you looking for something more modern looking? Try W1TS's 6C4-5763 MOPA in the October 1968 issue QST. Just add a resistor and 0B2 to regulate the oscillator B+ to 108V and include a switch to run the oscillator stage while keying the final.Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-85632367293146014132020-02-27T13:26:00.002-06:002020-03-01T10:25:52.185-06:00A Dingey size Boat Anchor on 30 mtrsAfter putting my <a href="https://w0vlz.blogspot.com/2020/02/putting-drake-2b-on-30-and-17-meters.html">Drake 2B on 30 mtrs</a> I immediately started looking for a matching transmitter. The trouble is, the WARC bands like 30 mtrs weren't created until about 1980, long after the novice requirement for crystal control had gone away. By then solid state VFO controlled transceivers were becoming the typical rig. I'd need to homebrew a transmitter if I wanted vacuum tubes and crystal control on 30 mtrs.<br />
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A search of the QST archives brought up three articles that helped me decide what to do. The first was WD8DQT's article in January 2012 showing how to use today's HC49 crystals in simple MOPA (Master Oscillator - Power Amplifier) transmitters. The other two, W1TS's in October 1968 and WD8DAS's in January 2003 each show 6C4 to 5763 MOPA designs that can be modified per WD8DQT's article to use HC49 crystals.<br />
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What next?<br />
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I already have a crystal controlled MOPA transmitter on my desk. See <a href="https://w0vlz.blogspot.com/2008/02/further-6j56l6-transmitter-developments_5846.html">https://w0vlz.blogspot.com/2008/02/further-6j56l6-transmitter-developments_5846.html</a> . I did a quick check and found that the 6J5 I used is a close match to the 6C4 WD8DQT based his article on. I could start with the 6J5-6L6 transmitter I already had. First I added a VR-105 and 12K 5 watt dropping resistor to power the 6J5 oscillator at 105 VDC. Next I converted the PA to a pi network instead of link coupled output. The tank capacitor is now 140pF and the output/antenna capacitor is now 300pf plus, optionally, an additional 300pF. The coils on 80 and 40 are the same B&W output coils I've been using but without the output link connected. For 30 mtrs I searched through my junque box and found a coil that loads up fine on 30. Finally, I found HC-49 crystals, including 30 mtrs, five for $7.50 on ebay. See <a href="https://www.ebay.com/sch/possumlodge/m.html?_nkw=&_armrs=1&_ipg=&_from=">https://www.ebay.com/sch/possumlodge/m.html?_nkw=&_armrs=1&_ipg=&_from= </a><br />
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My "new" 6J5-6L6 transmitter uses FT-243 and HC- 49 fundamental frequency crystals. It runs almost 12 watts input and about 6 watts out on 80, 40 and 30 ... outstanding! <br />
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See ya on 30. <br />
<br />Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-37098305618734185252020-02-23T20:38:00.003-06:002021-10-19T21:55:49.936-05:00Putting the Drake 2B on 30 and 17 meters<p>Recently I noticed the optional crystal frequency chart in my Drake 2B manual. It shows that a 14.0 MHz crystal allows you to listen to WWV on 10 MHz and 30 mtrs on 10.1-10.150. Nice, but wait, buy one get a second one free! The chart in the manual also shows that by retuning the preselector that same 14.0 MHz crystal also covers 17.5-18.1 MHz. This includes the lower half of the 17 mtr band. It looked like shifting the crystal up 100 KHz would shift coverage to include the entire 17 mtr band and still keep WWV and 30 mtrs on the dial. Outstanding!<br />
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A quick check of the AF4K Crystals website at <a href="http://www.af4k-crystals.com/" target="_blank">http://www.af4k-crystals.com/</a> shows that he stocks 14.1 MHz crystals in HC6 style holders.</p><p><br />
Range C on my 2B now covers WWV, 30 mtrs and 17 mtrs.<br />
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Where is Solar Cycle 25? </p><p><br />
</p>Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-16660328388574780132019-11-26T22:42:00.001-06:002019-11-30T07:13:01.926-06:00Christmas Vertical<div class="separator" style="clear: both; text-align: center;">
<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiKSS-rMJGXpkuBnYXEDNWX_ed6bHvGZb4ER9ZyI2xArG6OWSg4sXCu29jbAqaC9ykNlnO9Fh1qFL25Dz0g3tYO0oWEPHt4JiyjWjjJiLaOJBwbaTeDe5sJLG1r3Mu5nXVPTPcQHMuL1RrD/s1600/XmasVertical_2019.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="887" data-original-width="900" height="196" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiKSS-rMJGXpkuBnYXEDNWX_ed6bHvGZb4ER9ZyI2xArG6OWSg4sXCu29jbAqaC9ykNlnO9Fh1qFL25Dz0g3tYO0oWEPHt4JiyjWjjJiLaOJBwbaTeDe5sJLG1r3Mu5nXVPTPcQHMuL1RrD/s200/XmasVertical_2019.jpg" width="200" /></a></div>
Each year around Thanksgiving through about New Years I give up my 40 mtr vertical. That vertical makes a great support for our Deck Christmas Tree Lights and the timing fits fine between the AWA Bruce Kelley '29 CW Party and the ARRL Straight Key Night.<br />
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Merry Christmas!Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-45123075162575419812019-11-21T15:05:00.003-06:002019-11-21T15:29:05.230-06:00AWA Bruce Kelley 1929 CW Party - 2019<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGxN4yKys5RJ6Ik0hY3sVHEQ5aYBdZRtlyOJYl-5gJtJ7TeOIyNcIdlOUsxBQYXMcXIh01L2iFOp3zRpClMHyU_j-5eTwlcdO-p66upJN5l4IFGL0TWf2R3NCZCf8puDBrMYEGNdGERc4e/s1600/W0VLZ_BKLog_2019.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="899" data-original-width="1200" height="149" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiGxN4yKys5RJ6Ik0hY3sVHEQ5aYBdZRtlyOJYl-5gJtJ7TeOIyNcIdlOUsxBQYXMcXIh01L2iFOp3zRpClMHyU_j-5eTwlcdO-p66upJN5l4IFGL0TWf2R3NCZCf8puDBrMYEGNdGERc4e/s200/W0VLZ_BKLog_2019.jpg" width="200" /></a>Another BK is in the log. This year I worked ten other '29 stations. K0SM/W2ICE was worked outside of the party hours so Andy does not show up in my official BK log.<br />
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It was interesting that half of the '29 stations I worked were in MN and they all had, by far, the strongest signals. My 80 mtr antenna is only 15' off the ground. I suspect it was working well as a NVI antenna covering the "locals" fine. After trying all I could think of to clean up my 40 mtr signal I still wasn't satisfied so I stuck to 80. <br />
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My BK station stayed pretty much as planned for the first part of the BK using my new push-pull Colpitts and 1940 homebrew simple super but I felt I wasn't hearing as well as I might plus I was having trouble zero beating my own signal. I cobbled in my Drake 2B after the first night. It helped but contacts were still pretty slow. I also noticed a lot of signal wobble because of wind. I see all of my MN compatriots are running MOPAs. They may have a point.<br />
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What's next? The ARRL Straight Key Night on New Years Day followed almost immediately by the AWA<span style="color: black;"> Linc Cundall Memorial CW Contest. </span><br />
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<br />Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-85374975913213997882019-10-11T11:13:00.003-05:002019-11-08T10:30:07.676-06:00Winter Operating EventsThe first of this winter's Classic/Boat Anchor Radio operating events is on the horizon, only a few weeks away. I've been working on rigs since last spring. Now I'll have more chances to put them on the air.<br />
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First up is the <a href="http://www.antiquewireless.org/bruce-kelley-memorial-cw-qso-party.html">AWA</a><span style="font-size: small;"><a href="http://www.antiquewireless.org/bruce-kelley-memorial-cw-qso-party.html"> Bruce Kelley Memorial CW QSO Party</a> in early November. This one requires that transmitters be of 1929 or earlier design and use tubes available in 1929. I'll use my <a href="https://w0vlz.blogspot.com/search/label/1934%20Colpitts">Push Pull Colpitts</a> with either an SW3 or my <a href="https://www.prismnet.com/~nielw/3tube_xtal/3tube_xtal.htm">Simple Superhet</a>. If things get really tough I'll move my KX3 over for the receiver.</span><br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjEpdlOgSlfWS72tkERl9wjGGkgJdnbKOv8WfLi_Bk9EPWxhtKf9gTxFxWtc397mMDRK5voRE1KAINGrywIUmerNtmTYsQ4KBNuvUWFIpP4mG8EhwyLIrghHRGRDP_J_nMCx9btjvvpH0J/s1600/R4B_2NT.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" data-original-height="1151" data-original-width="1600" height="143" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgjEpdlOgSlfWS72tkERl9wjGGkgJdnbKOv8WfLi_Bk9EPWxhtKf9gTxFxWtc397mMDRK5voRE1KAINGrywIUmerNtmTYsQ4KBNuvUWFIpP4mG8EhwyLIrghHRGRDP_J_nMCx9btjvvpH0J/s200/R4B_2NT.jpg" width="200" /></a></div>
<span style="font-size: small;">Next is the <a href="http://www.arrl.org/straight-key-night">ARRL Straight Key Night</a> on New Years Day (UTC). This is ARRL's "Uncola" of contests (Does anyone remember those Uncola 7 Up ads?). It runs for 24 hours and has no scoring, only interesting QSOs. I'll probably bounce between several rigs but I think I'll have my Drake 2NT and R4B running as the primary station.</span><br />
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<span style="font-size: small;">Right after SKN, in mid January, is the <a href="http://www.antiquewireless.org/linc-cundall-memorial-cw-contest.html">AWA Linc Cundall Memorial CW Contest</a>. In this one extra points are scored for rigs designed before 1950. I've three stations that would fit but I've just gotten my <a href="https://www.prismnet.com/~nielw/nat_list/fb7.htm">National FB7</a> checked out and running again. I'll operate it with my "<a href="http://w0vlz.blogspot.com/search/label/1934%20transmitter">CW Jr</a>" as a 1934 station.</span><br />
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<span style="font-size: small;">Next is the <a href="http://www.novicerigroundup.org/">Novice Rig Roundup</a>. The NRR emphasizes rigs from the early Novice era when novices had to be crystal controlled and run only 75 watts. My Heathkit HW16 is newer for me so I'll run it on 80 and 40 for this event. The backup receiver will be my KX3.</span><br />
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<span style="font-size: small;">Finally, the <a href="http://www.antiquewireless.org/john-rollins-memorial-dx-contest.html">AWA John Rollins Memorial DX Contest</a> is in mid-March. This one emphasizes contacts on 40 and 20 using rigs designed before 1960. I'll have a chance here to use my Collins 75A4 with my Eico 720. This may not be a real DX station but, for me, it has a lot of class. </span><br />
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<span style="font-size: small;"><br clear="all" />Listen around and participate. All of these except the</span><span style="font-size: small;"><span style="font-size: small;"> Bruce Kelley Memorial CW QSO Party</span> allow you to join in using modern gear . If you hear me give me a call. </span><br />
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<span style="font-size: small;">This winter should be a lot of fun.</span><br />
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<span style="font-size: small;"><b></b></span>Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-20210229918985556102019-09-20T11:15:00.005-05:002019-11-08T10:29:04.138-06:00FB7 / Parallel 46s Station On the Air<div class="separator" style="clear: both; text-align: center;">
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This week I finally finished up my early 30s CW station using a <a href="https://www.prismnet.com/~nielw/nat_list/fb7.htm">National FB7</a> and a <a href="http://w0vlz.blogspot.com/search/label/1934%20transmitter">homebrew 1934 transmitter</a>. To-Dos that have been slowing me down are recapping the FB7, making a new power cable (and repairing the FB7 power cable) and then shoe horning everything into the corner I have available for it. Does anyone else have a shack that reminds them of the old advertising slogan: "There's always room for Jello"?<br />
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I got on the air looking for signal reports and RBN feedback. I had three QSOs that night (N4EDE/NC, W9BRD/NJ, W5RG/FL). All reported that my 10 watts sounded fine. <span dir="ltr"><span class="_3l3x">W9BRD, even gave me a "first rate note" comment. </span></span>27 hits on the RBN said I was also getting out. Great! I've another fun station to put on the air and it is a perfect match for the January 2020 <a href="http://www.antiquewireless.org/event-details-for-lc-cw-contest.html">AWA Linc Cundall CW Contest</a>.<br />
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What next? The <a href="http://www.antiquewireless.org/bruce-kelley-memorial-cw-qso-party.html">AWA Bruce Kelley1929 QSO Party</a> is coming up in November. I better get my <a href="http://w0vlz.blogspot.com/search/label/1934%20Colpitts">Push Pull Colpitts transmitter</a> back on line, tested and ready to go.Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-25936991831770219782019-08-24T14:55:00.002-05:002019-08-25T13:20:37.972-05:00Drake 2-NT Transmitter<div class="separator" style="clear: both; text-align: center;">
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Last week I traded some of my 1930s heavy metal for a Drake 2-NT novice
transmitter. At this point I'm interested in a decent rig I can carry
rather than heavy weight shelf queens that need the next door teenager
to get them out of the basement. What a great trade!<br />
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The 2-NT was introduced in 1966, late in the classic novice era when
novices were still limited to 75 watts CW only and transmitters had to
be crystal controlled. Around 2500 were produced. Within the novice
restrictions the 2-NT had features that put it far above the
competition. It was comparatively compact, included QSK or semi-breakin
transmit/receiver switching and had receiver muting. Also, 80 through 10
meter coverage made it attractive beyond the novice license. The keying
is set up so that the oscillator runs with a settable delay
and the buffer stage is keyed to minimize chirp. Drake did a fine job
with this rig.<br />
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The 2-NT was introduced with the Drake 2C but the 2-NT works well with a
lot of radios that have a built-in mute function. The receiver mute
function just needs to be designed so that the receiver mute terminal is
grounded for receive and left floating for transmit. This includes the
Drake 2B, the 4 line (R4, R4B, R4C) receivers and the SPR-4 receiver. WARNING: Drake did
this by wiring the mute function into the AVC circuit. Some radios may
do this by controlling the receiver B+. I'd be careful running receiver B+ into my
2-NT.<br />
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Now I needed to decide which receiver to pair with the 2-NT. While a
2C would be nice and would cosmetically and market wise match the 2-NT, I don't have one. I do have a 2B, an R4B and an SPR-4. The 2B is a nice radio but it is of the previous generation. For now I'll leave it paired with my Eico 720. The SPR-4 is the same design
vintage as the 2-NT and was Drake's first all transistor receiver. It is a fine example of what can be done with transistors in the mid 60s. Unfortunately Drake designed the SPR-4 as a high end SWL receiver. They didn't give me enough knobs to play with. AVC, bandwidth and passband are all fixed depending on the mode (USB/LSB/CW/AM) selected. Unfortunately the CW passband (and, therefore, the peaked CW pitch) is fixed at a higher pitch than my ears like. The SPR-4 went back on the shelf, possibly to wait for this winter and VLF experimenting. The R4B has adjustable bandwidth and passband along with AVC choices and it is of the right vintage. Like Goldilocks I found my third choice, the R4B, to be just right.<br />
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Together the 2-NT and R4B work great. I'll certainly have them on the air a lot. <br />
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The 2-NT is also featured in the Sept 2019 issue of QST, Classic Radio column.Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-41839832552916833052019-07-22T20:19:00.004-05:002019-07-23T21:11:21.703-05:00Push Pull 45s In the November 1955 issue of QST I found this accolade to the Push-Pull TNT transmitter:
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<span style="font-size: large;"><b>A Pair of 45s in Push-Pull<span style="font-weight: normal;"><br />
<span style="font-size: small;"><b>The words of<br /> Keith S. Williams, W6DTY</b></span></span></b></span></center>
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The other day a few of us were sitting around
chewing the fat, mostly cussing QRM,
'phone, c.w., single sideband, narrow-band
f.m., Novices, old timers, the FCC, the ARRL,
and the like. Joe Twerp, a ham of fairly recent
vintage, remarked, "Seems like everybody you
work nowadays has a Monster III transmitter.
I'll bet it's used by more hams than any other
single rig in the history of radio."<br />
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There was a general nodding of heads, all except for me and Hiram C. Hartley. Hiram turned to me and said, "Keith, do
you recall the 'Complete Amateur Transmitter
for Forty-Five Dollars'?"<br />
<br />
"I sure do!"<br />
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History's Most Popular Ham Transmitter was
first described in QST for November, 1930, in
an article by George Grammer. Its immediate
popularity was due to several causes, probably
the most important being the Depression. It was
pretty tough to keep beans on the table and a
signal on the air at the same time. The standard
transmitter of the day was a single 210 tube in a
Hartley oscillator with 550 volts on the plate.
This was a self-controlled transmitter, by the
way, directly or inductively coupled to the antenna.
Only rich guys had crystals and only a
few were so far advanced technically that they
could build a transmitter with two or more
stages. Type 10 tubes cost money, and the power
supply necessary in order to get decent output
was almost out of the question for the majority of
hams, whose billfolds were completely flat.
A majority of broadcast receivers in 1930 used a
pair of 45s in the audio output stage, with a Type
80 rectifier in a 350-volt power supply. Therefore. 45s and 80s were comparatively cheap and
plentiful, and the corresponding power supply
components were easy to acquire. The Type 45
had been a widely used audio tube for some time,
but the manufacturers stated emphatically that
the tube was not suitable for use as an oscillator
so hams hadn't tried it in transmitters.<br />
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Grammer's article in QST stated that all parts
for the push-pull 45 rig could be purchased new
for $45.00 or less. Actually, the only parts ordinarily bought and paid for were the power
transformer, filter choke and wet electrolytic
filter condenser. All other parts, including the
pair of 45s, were usually scrounged. (Many were
the families who couldn't hear Morton Downey
because Junior had pinched the 45s out of the family BC
set and was upstairs stoking them up on 80.) In
some cases the quarter-inch copper tubing for the
tank coil had to be bought, but even this item
could usually be managed without breaking the
piggy. bank. The rig was built on breadboard.
Well, it was actually built on anything handy, but
rigs in QST were always built on real, honest-to-gosh. breadboards — the kitchen-cabinet variety.
It was a push-pull self-controlled oscillator. It
had a medium high-C plate tank for a modicum
of frequency stability, an untamed grid coil, an
antenna tuning condenser, and two or three
small parts. It was simple to build and sure-fire
in operation — the answer to a ham's prayer.<br />
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The appearance of this rig in QST coincided
with a tremendous upsurge in the ham population. With the Depression, a large number of
people found themselves with time on their
hands. Those who couldn't get a steady job selling apples began to take up inexpensive hobbies in
order to keep occupied while waiting for the NRA
and the return of beer and light wines. Ham tickets began to be issued in droves. Commercially
built ham gear, except for a few items like the National Thrill Box and the Pilot Super Wasp, was almost nonexistent and it was a rare would-be ham who could afford ready-made equipment, anyway. However, with Grammer's contraption you could get on the air for next to nothing and enjoy the thrill of talking to distant places by short-wave radio! Practically every new ham built the push-pull 45 transmitter and started out pounding brass on 80-meter c.w. Old timers who built a new rig in those days usually ended up with a pair of 45s in push-pull. Beginners generally started on 80 meters because self-excited transmitters usually tended to behave in a civilized manner on that band but could be unmanageable brutes on the higher frequencies. The push-pull 45 rig I had on the air in 1932 was very tame on 80 — most of the reports I received were either "PDC" or "NDC" and once in a while some liar would give me a "XTAL PDC" report and I would like to bust with pride. But on 40 meters, although the rig put out gobs of r.f., the note sounded like a buzz saw ripping through knots; on 20 meters the 45s ran red-hot and smoking while putting out about two watts to the antenna. I must say others had better luck.<br />
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Yes, indeed, that push-pull 45 rig was without doubt the most popular ham transmitter ever to be seen in W-land. After Hiram C. Hartley mentioned it the other day I got to pawing back among the stacks of old QSL cards stowed away on a closet shelf. I picked up a batch of old cards, circa 1932. Out of the first 38 cards, 24 cards said, "XMTR: PAIR 45s IN PP." That's 63 per cent, and I can easily believe that from 1931 to 1934 at least 63 per cent of all hams in this country were using that identical rig.<br />
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<div style="text-align: center;">
<span style="font-size: x-small;">( Reprinted with the permission of the ARRL. Copyright ARRL.)</span></div>
<br />Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-27019167538906959882019-05-01T16:34:00.000-05:002019-05-01T20:15:51.014-05:00A fix for drift?Does anyone else have a slow drift problem with their Hull Hartley? I was looking at mine and spotted something I wanted to check into.<br />
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The center tap resistors for the filament are mounted right under the tuning cap. Any heat they generate goes right to the tuning cap. Hull suggests 50-200 ohm resistors there. I used a couple of 40 ohm resistors thinking that as long as my power supply can handle the extra current draw I'd be ok. Now I have a .7 watt heat source where Hull's design had as low as a .14 watt heat source there. Any heat might cause a problem. oops.<br />
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These two resistors are in the circuit to provide a ground point for cathode keying, but there is an alternative. I have a center tapped 7.5 V filament supply. I can remove those two 40 ohm resistors and just key the filament transformer center tap. The heat source will be removed so my Hartley should now stay on frequency better.<br />
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*** clock ticks while solder smoke rises ****<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikWB99q0J0gDa3P2DARq2GzK15bE2mLGaOvPUDxpNocCp2dRUl3Fq9duoShe3vYZ3yu6QhXz57gtu0KSSOOzWNurkGVp5qtLPlyFMRQ2WMvdTInQyF-kwoF65RHX2hqrQ3wsGnFMrrSVPt/s1600/CentertappedHartley.JPG" imageanchor="1" style="clear: right; float: right; margin-bottom: 1em; margin-left: 1em;"><img border="0" data-original-height="848" data-original-width="1200" height="141" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEikWB99q0J0gDa3P2DARq2GzK15bE2mLGaOvPUDxpNocCp2dRUl3Fq9duoShe3vYZ3yu6QhXz57gtu0KSSOOzWNurkGVp5qtLPlyFMRQ2WMvdTInQyF-kwoF65RHX2hqrQ3wsGnFMrrSVPt/s200/CentertappedHartley.JPG" width="200" /></a></div>
Well, I removed the 40 ohm filament center tap resistors from my Hull Hartley. It is a fairly clean change. The only visible indication of the modification is the addition of one fahnestock clip along the left side for the transformer center tap connection. Now that heat source is gone.<br />
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I did before and after standby drift measurements. After tuning on the rig I checked the transmit frequency every 30 seconds for 15 minutes. Key down was only long enough every 30 seconds to get a transmit frequency readout. I had no load connected and the plate current was about 18mA with 300 volts B+.<br />
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Was is worth it?<br />
<br />
*** Now drums rollllll ***<br />
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It depends<br />
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On 80 meters I found that the original Hull design drifted about 2KHz from a cold start while the modified version drifted about 500Hz. That's good but both took about 15 minutes to settle down. With both versions I still have to be careful about jumping on the air right after power on. I saw no significant change on 40.<br />
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But two parts were eliminated along with some amount of power on drift, both good things. <br />
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If I were starting out now building my Hull Hartley and I had a center tapped filament transformer I'd make this change. If I already had my Hull Hartley up and running, I'd probably let it be.Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-84499285548749837562019-04-16T21:08:00.000-05:002019-04-17T15:29:31.182-05:00Push-Pull Colpitts Transmitter - 8I've had my Push-Pull Colpitts on the air now for about 3 weeks and 10 QSOs. Notable QSOs have included my friend Lou, VE3AWA, in Ontario and W0NYQ, a fellow Minnesotan with a big interest in '29 rigs. <br />
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This tranmitter is a keeper. Why?<br />
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- Efficiency is 50-60% (great for a '29 power oscillator)<br />
- Drift is measured in the 10s of hertz range. Essentially solid as a rock.<br />
- No hand capacity problem when tuning to get on frequency<br />
- Easy to adjust feedback for minimum plate current and best performance<br />
- "Perfect sounding 1929 signal" <br />
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I did receive a report of a trashy buzz on my sidebands. Since then I've been more careful when adjusting the feedback and also the output coupling. I haven't had any other bad reports.<br />
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I do still have some trouble with FMing/wobble due to the wind blowing around my antenna. This is a common problem with '29 power oscillators. Whether this is an improvement over my other '29 transmitters, I can't tell.<br />
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I haven't cleaned it up on 40 but I can work on that later.<br />
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All in all, a really satisfying project.<br />
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<br />Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0tag:blogger.com,1999:blog-4184250009182241972.post-28045759988986363452019-03-29T17:19:00.002-05:002019-04-06T04:12:51.990-05:00CW on 3565 KHz<br />
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<a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgr1AfsCCz8-Svc9Ao7H_3GInqlFZKXw3Y6CrYmAVGkFEhrLISqlPRByq5o6tNmKpimoS0lMoznOJcHrI2o0LimQ55KEXl7twH93IZR69sHxrQvhV9fDXX4wsz2ub5dtP8ctU0A8Kkt-XEN/s1600/W0VLZ_25Mar2019.JPG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" data-original-height="420" data-original-width="1200" height="140" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgr1AfsCCz8-Svc9Ao7H_3GInqlFZKXw3Y6CrYmAVGkFEhrLISqlPRByq5o6tNmKpimoS0lMoznOJcHrI2o0LimQ55KEXl7twH93IZR69sHxrQvhV9fDXX4wsz2ub5dtP8ctU0A8Kkt-XEN/s400/W0VLZ_25Mar2019.JPG" width="400" /></a></div>
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Push-pull Colpitts power oscillator on 3565KHz with 6 watts into a low endfed wire as copied by VE7SL in British Columbia, 1490 miles to the west:
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Niel - W0VLZhttp://www.blogger.com/profile/09860694874162459879noreply@blogger.com0