More TZ-20 Amplifier

With the chassis and front panel drilled, punched and painted this project should start looking more like a kit. Everything is in hand, all I need to do is mount, wire and solder.

I laid out the chassis and front panel so that eventually this amplifier will serve as an upper deck of a 70 watt CW transmitter. My 1934 transmitter will be the lower deck/driver.

Springtime - QRPtime

With an early spring here in SE Minnesota I can start thinking about QRP again. One of my favorite local picnic table QRP spots here in Rochester is Essex Park. It has plenty of space, lots of trees with limbs about right for antenna supports and movable picnic tables. Take a look here for a video on my operating from Essex park. On Saturday I worked N1LU, Don in NH, and K1TG, Roger in CT. K1TG was an especially good QSO. We are both active in the AWA and have worked each other using our vintage stations.

This weekend at Essex Park I also worked on a new antenna. My end fed half wave and full wave wire antennas do a fine job but they require at least one well placed tree. I could use a self supporting antenna. Cabellas (and other big box sporting goods stores) sell a 16.5' collapsible crappie (as in fishing) pole. 16.5' is just about right for half of a 20 meter dipole. On Sunday I setup two of these poles to form a V to support a V (not inverted V) dipole. Read more about this antenna here. It appears to work as well as a straight dipole and it is fairly portable....now I need to find a bare nob of a hill to operate from.

National TRM 56 MC Transceiver

Last week I acquired a 30's vintage National 56 MC transceiver. Read about this model on my web site at http://www.prismnet.com/~nielw/TRM_TRW/TRMpage.htm . The TRM and the wooden cased TRW were two of the first commercially available VHF radios. At only 6"x6"x7.5" and 8.5 pounds it is amazingly heavy for it's size. The two special National transformers add a lot to the weight.

I don't find much information about the TRM. What I've found is from National's 1935 catalog and a 1933 article that, while it doesn't mention it by name, appears to describe the TRM. None of my catalogs mention the TRM or TRW after 1935 but my TRM has a model tag. National didn't but tags on their equipment until after James Millen left in 1938. This one must be a late model.

Another Swapmeet Find

Here's something that I keep around to show visitors that hams really did build the transmitters described in QST. Take a look at my version of George Grammer's push-pull TNT transmitter. This one here is a lot worse for wear but it is recognizable.

Swapmeet Find

Every once and a while over the years I've picked an item at a swapmeet just because it was interesting and if it could talk would have a story to share.

Here's one. I don't remember when or where I got it but probably at a central Texas swapmeet a few years ago. Some one on a budget wanted to get into ham radio. The local trash heap contributed an old crystal set complete with loose coupler. The tuning coil was rewound as the antenna transformer primary. Some tuning was allowed by striping off insulation in a few places. The loose coupler became the antenna coil and allowed variable coupling. I found a section of the Sunday comics shoved into the loose coupler to keep it in place..date1930. Two of the holes on the board next to the spark coil match the mounting holes for a Bunnell telegraph key.

More RF Amp

A push-pull amplifier is two tuning caps, two coils and two tubes right? With all of the support circuitry, the output loading circuit I like and miscellaneous parts and hardware it is starting to look like a real project. Once the drilling is done this one will sit until warm weather returns to Minnesota (maybe May?). I want to paint the chassis but not with snow on the ground and temperatures in the 30s.

RF Amp

Most of my 30s vintage transmitters are in the 10-20 watt range. It would be fun to have a little more power, especially with my 10 watt Meissner Signal Shifter / VFO. According to the specs two Taylor TZ20s in push-pull can be driven with 5 watts to about 110 watts input or 85 watt output. This sounds like what I'm looking for.

As usual any project starts with sorting through parts and then doing a preliminary layout before taking a drill to the metal.

1929 and 1930 Stations

Lots of times questions get asked about what sort of rig to put on the air as a 1929 station. What were hams really using? Do the back page ads in QST really reflect what was on the air?

As I went through my old issues of the AWA OTB/Journal I found Bruce Kelley's comments on 1929 equipment in the May 1994 issue. He summarized 1929 and 1930 QSL card information from W1NE. He saw that Hartley oscillators and the 210 dominated the transmitter scene and almost 90% of the receivers had no RF stage. I found two 1930 QSL cards in my collection and added those to Bruce's tabulation. I've posted this data at http://www.prismnet.com/~nielw/OldQSLCardInfo2.pdf .

If you have similar 1929 or 1930 QSL data email it to me and I'll add it to the summary.

AWA Linc Cundall Memorial OT CW Contest

For two days this past week I participated in the AWA Linc Cundall Memorial OT CW Contest. This contest gives a significant multiplier to those using pre 1947 gear. I used a National NC-101X and one of my recent homebrew transmitters, a "46 job". I worked nine stations in four states plus Ontario.

Photo QSL Cards

QSL cards are a ham radio tradition that I was introduced to when I was a novice in 1966. My novice card then was a fairly generic design ordered 100 cards at a time from the Little Print Shop near Austin, Texas.

These days I usually custom create my QSL cards to go with a particular event or location. Lots of places will print digital photos and most allow on-line submission. I've seen prices as low as 9 cents per print with no minimum. All that is needed is a jpg file the right size.

Start with your favorite graphics editor, even Microsoft Paint has enough power and function to do the job.

First create a blank colored background with the right aspect ratio to match the prints to be ordered. I planned to order 4" x 6" prints so I created a 800 x 1200 pixel background. This background gives you control over auto resize/crop that occurs when your file is printed. The color doesn't matter. It will eventually get trimmed off.

Use your editor to cut out from the middle of the background a rectangle the matches the final size of the QSL card. For a typical 3.5" x 5.25" QSL card on a 800 x 1200 pixel background this rectangle will be 700 x 1050 pixels. This space is where you create your QSL card.

Use your graphics editor to add whatever QSL card text and images you wish. For Microsoft Paint I found it best to crop and resize any photos or images before I paste them into the QSL card.

Send the jpg file off to be printed.

The resulting 4" x 6" print will have a colored frame that needs to be trimmed off. This should leave your 3.5" x 5.5" QSL card. A paper cutter works great for trimming.

Other cheaper options may be available but for the QSL card information I use a Avery #5264 3.25" x 4" shipping label stuck to the back of the QSL card. Inside the Avery box are instructions telling how to use a template included in Microsoft Word to create six preprinted labels per sheet of shipping labels.