Boots for a KX3

I finally got the relay box finished so that I can use my grounded grid 572B amplifier with my KX3. On receive it bypasses the amplifier and delivers -100VDC cutoff bias. On transmit the 572B grid is grounded and the KX3 output is routed through the amplifier.

Lacking a triple pole-double throw relay I used a double pole-double throw relay to transfer the antenna and a single pole-double throw relay to switch the cutoff grid bias. The two relays run off of 12 VDC but together require about 1/2 amp, way more than the KX3 Keyline Out line can handle. A "Keyall" board from Jackson Harbor Press/WB9KZY solved that problem. Ideally I would have used a single transformer that delivered 12VAC and 100VAC for the two supplies. Lacking the ideal I used back to back 12V transformers. One toggle switch was added to allow manual send/receive control without the Keyline Out signal from my KX3. Another toggle switch was needed to power on/off the 12V/100V power supply.

When I use the relay box and my amp, the KX3 antenna tuner has to stay in the circuit in order to match the transceiver to the uncontrolled input impedance of the amplifier. In addition the antenna relay can not follow break-in CW keying without losing the first dit so I must use the KX3 in PTT mode. On the plus side I run about 80 watts to the antenna instead of 4, maybe not a big deal for CW but real help for SSB.

A Nice Day in Minnesota

Today, with nice weather and nothing on the calendar,

Beth and I headed for Frontenac State Park, one of my favorite places for picnic table QRP. The picnic area at Frontenac sits on a bluff overlooking the Mississippi. The view is great, the trees are plentiful and there's nothing to get in the way of my signal.

SOTA Trip to Steptoe Butte

On Sunday, August 4, I went a little beyond my regular picnic table QRP sort of laid back operating. With some spare time while visiting in eastern Washington, I decided to do a SOTA activation of Steptoe Butte.

Summits On The Air is an award scheme for radio amateurs and shortwave listeners that encourages portable operation in mountainous areas. See http://www.sota.org.uk . Basically "Activators" operating from mountain summits and "Chasers" both get credit towards awards.

Steptoe Butte rises about 1000 ft above the Palouse farm country. Located 50 miles south of Spokane, WA. it is within sight of Idaho. It is a state park with easy access to the summit.

As a SOTA activator I hiked the last feet to the summit and then set up my KX3 at the edge of the Steptoe Butte summit overlook. There are no trees on the summit so I strapped my 18' crappie pole to a rock pedestal, using it to support the high point of my 20 mtr end fed zepp.

I had posted to the SOTAwatch2 database an announcement of my intention to activate Steptoe Butte. My first CQ was picked up by the Reverse Beacon Network, compared to SOTA database and an activation spot automatically posted to the same SOTAwatch2 database. Instantly any SOTA chaster knew my frequency and operating status. I'm used to calling CQ for a while and getting one or, at most, two responses...suddenly it felt like I had a pileup to work, unfortunately I've no practice working pileups. In less than two hours I did work 15 stations in 9 states but I could have done better.

Notes to self for the next time:
- Copy directly to a log sheet rather than my QSO pad
- Avoid using my cellphone clock requiring me to punch it to get the current time
- Narrow selectivity first
- Use RIT to tune through the pileup for calls

and, a related safety item:
- If the antenna is within easy reach of curious public, hang a "Do Not Touch" note on it.

Hopefully next time I won't leave so many chasers without a QSO.

Another way hang a C-Pole

When winter turns into summer I usually take down my 80 meter antenna and put it away. This year Beth was flexible enough to let me leave the mast in place and hang my 20 mtr C-Pole from it.

So far it has worked out well. I've only had this up for a couple of months but it's been through 16" of snow, record amount of rain, thunder storms, wind...it hasn't come down yet.

The mast is made from six sections of military surplus 4' fiberglass poles. These are the ones made to support camouflage netting and have a reinforcing ring at one end. They fit together pretty tight. There's no need to bolt sections together.

I just run the C-Pole antenna top spreader up the pole like a flag. It sways a little in the wind but does not twist around enough to be a problem

The bottom spreader is hooked to the top of the balun (http://w0vlz.blogspot.com/2012/08/a-balun-for-phased-c-poles.html ) . The balun is captured by the conduit hanger it sits on top of.

The antenna is mounted approximately 16' from the house and only a few inches from the deck railing but at QRP power levels has not been a problem.

I didn't use any guys, just a clamp to the deck railing approx 10' off the ground and a hinged clamp staked in to the ground. (The radials in the photo are left over from an earlier antenna project and just left there.)

It's not quite Spring in Minnesota

Last week Beth had an all day conference scheduled in the cities. I had the day free so this sounded like a great opportunity for some QRP in a different park.

Plans are made to be changed. The night before Beth's conference we got over 6" of snow and the temperature was forecast to be in the mid 30s. In the past I have participated in the FYBO QSO party but I wasn't planning on it this year. Where might I operate my KX3 from while staying warm and dry?

Eventually I thought of the Pavek Museum of Broadcasting. Located in St Louis Park, just west of
downtown Minneapolis, it is home to a great collection of antique radio, television and broadcasting equipment. It also includes a ham radio club, W0OEP, built around two Collins stations. On Friday I was more interested in the beam outside.

Steve Raymer, the museum curator, helped me get my KX3 plugged into the club yagi and I was on the air, warm and dry: a good combination for a cold snowy day in Minnesota. 20 mtr CW QSOs included VE3OF in Ontario and KK4BOB in Florida. Operating time was interrupted a couple of time, once while Steve demonstrated the museum spark transmitter and the other for a museum guided tour.

Spring and QRP in the Park

Unfortunately spring hasn't yet arrived in SE Minnesota. It has, though, in central Texas. A couple of weeks ago Beth and I were down in Austin, TX visiting friends. My KX3 bag has a designated spot in the car. I rarely leave town without it.

During the week in Austin I enjoyed QRP QSOs with KA3J, W8WL/0, WA9FZP, KC2ZBZ and KI4TS. The most interesting QSOs, though, were the eyeball ones. On April 1 an old friend Dick, W5TA, stopped by for a visit while I was spending a few free hours in a Pflugerville city park.

On April 5 Beth and I took a trip down to Bastrop State Park. Unfortunately, in September 2011, 96% of the park was burned.  Only around 100 acres were saved. The rest is still blackened tree trunks. While set up and operating from one of the overlooks Jerome and his family came through on a hike and stopped for a rest and a snack. His young son wondered what was going on at the next table. Introductions led to a nice conversation about ham radio and a demonstration of morse code.

AWA LC CW Contest

Last week was the AWA Linc Cundall Memorial CW Contest. I used my 1934 style crystal controlled oscillator-buffer (47 to two 46s in parallel)  driving two TZ-20s in push-pull. The receiver was a 1936 vintage HRO Sr.

QSOs included W0CWU (MN), K1TG (CT), VE3AWA (ONT), N0EK (ND), WA9WFA (MN) and WB8APR (MI). Unfortunately, as I wrapped up with WB8APR, my transmitter output dropped to zero. Earlier I had had a hint of trouble when two stations reported chirp on my signal. I was keying the buffer stage, not the oscillator. Any chirp should have been slight. Contest or no contest the transmitter wasn't getting better by itself. After a few minutes of tube swapping and coil reseating I knew I wouldn't be back on any time soon. Eventually I found the problem: a bad solder connection. A little heat and solder fixed it. I had a working transmitter but I couldn't turn back the clock. The contest ended without my making any more contacts.

The HRO Sr and a three stage crystal controlled transmitter does make a nice late 30's CW station, though. It is one of my favorite winter operating positions. I'll be on it a lot. After all it is below zero today, I'm certainly not heading to the park.
 

Bruce Kelley Memorial 1929 QSO Party

This past weekend I was able to put a 1929 transmitter on the air and participate in the AWA Bruce Kelley Memorial 1929 QSO Party.

I stayed on 80 meters making 18 contacts. Stations worked were as far west as VE7SL in British Columbia, as for east as N1BUG in Maine and even a little south to N4GJV in North Carolina.


This year I used a transmitter I acquired from Vance, K5CF (SK). Vance, my step father, gave me my novice test in 1966. He enjoyed ham radio for over 70 years. Several years ago Vance encouraged me to participate in the 1929 QSO Party. Vance's transmitter is a TNT (or Tuned plate Not Tuned grid) transmitter using a single type 210 tube. With 340 volts on the plate it runs 9 watts input and about 2 watts out. Vance built his transmitter based on the one Bill Orr described one in the January 1973 issue of CQ but the original design dates from the 20s. See the December 1929 issue of QST for George Grammer's version of the same transmitter. For an antenna I used a 105' end fed inverted L only about 15' off the ground.

Bruce Kelley Memorial 1929 QSO Party Preparation

Last night I set up my station for this year's AWA Bruce Kelley Memorial 1929 QSO Party. I decided to go with my TNT transmitter this year and, as a book end for ham technology, pair it with my Elecraft KX3 running as the receiver. With 275 volts on the 210 plates my TNT transmitter runs at just under 10 watts input. Output is 2-3 watts....about to be expected for this sort of transmitter.

After confirming via the Reverse Beacon Network that I was indeed getting out on 80 I tried a QSO this morning. I worked W4DBV near Nashville, TN. When quizzed about my signal Bryan reported:

 "I can't really assign your tone a number, and my verbal description is about as close as I can come.  I have heard much worse, and I have also heard other rigs that are about the same as yours -- usually vintage or HB vintage designs, most running QRP levels of power.  Your note did not have a frank buzz, I can say that."

While not the best signal report it will certainly do for this weekend. In the meantime I'll play with the loading to see if I can improve it a little.

A Choke Balun for Phased C-Poles

It is important that the baluns used in a phased verticals match, otherwise the phasing, beam pattern and gain won't be as planned. They also must handle the high common mode potential at the feedpoint. KF2YN shows two different balun designs in his April 2004 article. One is just multiple turns of coax wound around a piece of PVC pipe while the second uses a ferrite core. The ferrite core design, while more expensive, also has much less power loss. For my phased verticals I chose Brian's toroid design. It uses 19 turns of RG-174/U coax wound on a FT-240-67 core. I mounted mine in plastic electrical boxes with an eye-bolt to allow hanging from the bottom C-Pole 40" spacer. This balun does no impedance transformation. The balun coax is simply in series with the antenna feedline.