New Paddle for my KX3

The homebrew paddle that I pack with my KX3 is durable but weighs in at 2.2 lbs, a heavy weight by any standard. I finally looked around for a lighter weight replacement and found the Palm Pico Paddle. At only 1 oz this one will certainly pack easier. I've now had a few QSOs with it and I couldn't be happier. This one works fine and will pack along on my next hike a lot easier.

The Pico Paddle comes with a magnetic base and a cord for connecting to the KX3. The size is perfect for the right hand side on the KX3, fitting just below the right hand endplate mounting screws and above the antenna connectors. Elecraft does recommend a right angle plug. I found one at Radio Shack. Palm Radio offers a steel KX3 endplate that works with the magnetic mount, but not one with handles. Instead I ordered a piece of steel that sticks on the KX3 endplate to provide something the Pico Paddle magnetic mount will stick to.

I wondered about using the Pico Paddle stand alone. It is a little small for sitting by itself on the desk but I found that the magnetic mount works great with a blank steel electrical box cover.

Phil Moorey has a good suggestion:

You might want to hot glue a piece of metal to a plastic sheet about 5" by 6". You can use the plastic as a clipboard for notes and the weight of your hand secures it when sending. A couple of rubber feet helps prevent sliding on a flat surface. I have been doing this for years.

Addendum, Feb 6, 2014
After seeing Phil's suggestion above I was motivated to return to my local big box hardware store in search of a different stand alone base plate. This was to be used only in the shack so weight was not a big issue. What I found in the plumbing department was a 5"x8" 16 gauge "Steel Safety Plate". I then located soft rubber non-skid "Gripper Pads" designed to stick on the bottom of table legs to keep them from moving. I now have a base for my Pico Paddle that works great at the shack operating position.

Addendum, Apr 21, 2014
The only problem I have is that I tend to be heavy handed enough that I can loosen the paddle from the KX3 when it is set up with the magnet on the side. For me I'll probably leave the magnet on the bottom and pack along a piece of flat metal (like a 3 1/8"  x 7" steel joist tie plate) to use as a base out in the field. 

AWA Linc Cundall Memorial OT CW Contest

Between 80 and 40 I managed twelve contacts using my National HRO Sr and TZ-20 transmitter with a low hung inverted L antenna. By contesting standards not a lot but still better than any of my LC QSO counts going back 20 years.

I worked nothing to the west but I did manage Qs to Canada, the east coast and southwest. I heard N2BE a lot. Too bad I could only work him once per band. I was surprised to not hear many of my MN friends on the air. Of the eight I worked in the BK I only heard three on for the LC.

I have grown to depend on the Reverse Beacon Network to help me decide if the band is dead. If I call CQ and I don't get a lot of feedback from the RBN with reasonable signal strength it's time to change bands or go to bed.

Straight Key Night

Last night and today was the ARRL Straight Key Night . This 24-hour event (00:00-23:59  GMT, January 1) is not a contest; but a day to get on the air and simply make enjoyable, conversational CW QSOs. There are no points scored. Hand sent CW (either straight keys or bugs) is preferred and, in fact, helps identify those in the event. SKN certainly fits my operating style.

I did need to wire up a cable to plug a straight key in to my KX3 but, with that, I was on the air. 20 seemed to be fairly active this afternoon. Running my usual 5 watts I got a 589 from WA9ZWA, Terre Haute, IN, a 559 from W2LG, Leesburg, FL and a 599 from AE1T, Plymouth, NH.  No DX but with the outside temperature hovering around zero today it made for a relaxing time in the basement with my radios.

KX3 Filter Settings for SSB, CW and Data

While setting up for the AWA '29 QSO Party I started playing more with the KX3 filtering and audio response....mostly because 80 meters seemed particularly noisy that night. I found something that really helped me see the interaction of the various receive selectivity options: Rcv Audio Equalization, Notch, APF, Data/RTTY mode, Passband Width, Passband Shift and Passband Hi/Low Cut.

I downloaded DigiPan from http://www.digipan.net/ (Freeware) onto my laptop, not for the PSK31 function but for the waterfall. I then configured DigiPan to use my laptop built-in mic as the audio input/source. With my laptop sitting next to my KX3 I tuned to a unpopulated but white noisy frequency. This may require the preamp to be turned on. While watching the white noise on the DigiPan waterfall I tweaked the various filter settings. The white noise waterfall display changes to reflect the filter settings, clearly showing me the impact of what I was doing. SSB, CW and data signals can even be tuned in and viewed as the various selectivity options are changed. The KX3 CWT Aid and the Filter Passband Graphic show some of this but not to the detail of the DigiPan waterfall.

For example here's a sample waterfall showing the impact of narrowing the KX3 bandwidth setting followed by adding the Audio Peak Filter (APF). The horizontal scale is frequency (in Hz) and time is the vertical scale.  The CW signal of interest is the yellow streak at 520Hz. Interference is the yellow (stronger) and blue (weaker) around the 520Hz signal.

1929 BK QSO Party

The past two weekends I spent 4-5 hours operating in the BK. I had 16 QSOs
and worked five states including NC, MT, MI and ME. Background noise levels were pretty high but even with about 2 watts out I still made contacts.

I'm not pleased with the way my TNT transmitter sounds on 40. After an initial excursion into that band on Dec 7 and then critically listening to my own signal I decided to stick to 80.

1929 BK QSO Party

I'm set up for the AWA Bruce Kelley 1929 QSO Party. This year I'm using my TNT transmitter with two 45 triodes in push-pull .  This transmitter has an output of only 2-3 watts with 10 watts input, about typical for self excited oscillators like this connected directly to the antenna. At first I thought I'd also use a vintage receiver but I switched to my KX3.

Tonight I did work KK4HCF in TN and WA1KPD in CT  heard me so there is hope for the QSO Party.

More about a power supply for a 1939 Transmitter

Plans change....after studying my collection of available transformers I found one rated at 560 (center tapped) at 270mA. This would work well with a full wave bridge rectifier as the TZ-20 final stage B+ (550VDC). Half of this, full wave center tapped rectified, is about right for the buffer stage (270VDC) and a VR-150 should be able to take this down to 150V for the oscillator stage.

I recalled Brian, WA7PAC's, comment to me several years ago when I was
dealing with a similar problem on a different transmitter. He suggested an "Economy Power Supply". Rather than clone my one transformer it's possible to run it with both a full wave bridge rectifier and a full wave center tapped rectifier.This looks like it may work.

I'm using PSU Designer II to help me play with filter options before I put solder to the iron.

A power supply for a 1939 Transmitter

With my KX3 n the shop because of a bad output transistor and cool weather returning to SE Minnesota I'm again in the basement looking at boat anchor projects. One project on my list is to clean up the power supply for my 1939 transmitter. Right now I've borrowed the power supply from my 1951 novice station to power the oscillator/buffer stages and used a second 500VDC supply for the TZ-20 amplifier stage. Needless to say, these don't show up in my blog photos of the transmitter.

My new power supply is a pretty brute force design delivering 550VDC, 300VDC and 150VDV to the transmitter using two power transformers, a couple of 5R4 rectifiers, a VR-150 and the needed filtering circuits. It will be two fairly heavy supplies on one chassis.

I found all of the transformers and components in my junque box but not a stout enough chassis for all of the iron. I turned to my slat board design to take care of this shortage.

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.