W0VLZ Shack

Ham radio has a lot of different facets of interest, mine happens to be radio technology and the way it has changed over the years. For me it is neat to be able to play with radios from different years and technologies so that I can see for myself the impact of design changes.

In the early days of ham radio many of the rigs were home brew or home built. Part of my interests also includes constructing gear using plans from the early days of ham radio. My shack has several examples of vintage home brew.

My shack reflects this interest in different ham radio eras. I have multiple operating positions set up in my basement so that I easily get on the air with different transmitters and receivers. I can see, hear and feel what it was like to be on the air 50 to 100 years ago.

One section of my shack reflects the 20s and early 30s technology. Some positions are for rigs of the mid 30s through the 40s, an exciting (or "golden age") time for ham radio technology. Several operating positions show off rigs of the classic novice years: 1950s and 60s, CW only, crystal controlled and power of 100 watts or less. One final position is filled by my Elecraft KX3, a modern Software Defined Radio.

 

 

 

 

 

 

 

 

The Hero of Hallettsville - A QSL-40 Transmitter works to bring aid

I acquired this ugly transmitter from a guy that said it came out of a defunct radio museum in Houston, TX. It came with a label “The Hero of Hallettsville”. Hallettsville is a small town west of Houston. Could this transmitter have belonged to some ham struggling to stay on the air as a hurricane roared around him? Perhaps he provided the only communication with the outside world as roads flooded and telephone lines went down. The true story behind this transmitter is close to exactly that.

In two days in late June of 1940 south central Texas had over 22 inches of rain. This caused destructive floods in the area and seven people died in the Lavaca River at Hallettsville, Texas. Property and crop losses were estimated at more than $1 million. An article in the Sept 1940 issue of QST (pg 60) reports details from the ham perspective.

On Sunday morning, June 30, 1940 Hallettsville put out a plea to hams for help. The town was completely cut off, flooded, needed boats and doctors and had no outside communications. Water was 8 feet deep in the stores in town. Houston, Texas hams responded by gathering emergency equipment and heading for Hallettsville. Along the way water was over the running boards of their borrowed Texas highway department truck. At one point they found the road gone and those attempting to cross in boats up in trees where they stayed until the water receded. There the hams stopped and got on the air. One of their rigs was W5CVQ's 6L6 transmitter made up like a QSL-40 but with a padding condenser that could be switched in for 3.5Mc. Eventually the water went down enough that the Houston hams managed to get across and into Hallettsville to setup in City Hall. They were on the air for 24 hours handling requests for help and supplies, broadcasting flood reports and warnings and sending “personal messages of safety to relatives of the marooned populace”. During this time the little 6L6 rig proved to be a valuable help.

This little transmitter is certainly that 6L6 rig. It is built along the lines of the QSL series of CW transmitters described in QST before WWII and has an extra padding condenser that can be switched in via the toggle switch on the top panel. It looks like parts were scrounged from a variety of places including the kitchen trashcan. The broken and repaired panel, hacked tin can chassis and hasty paint job all say function before beauty. View the inside to this transmitter by clicking here (160KBytes).

The QSL-40 series of transmitters were designed by  Fred Sutter (W8QBW/W8QDK). The name comes from the size. It is about the size of a QSL card and includes one tube, a crystal, plate current meter and a plug-in coil. The QSL series of compact 6L6 transmitter designs appeared in QST starting with the QSL 40 in February 1938 and ending with the QSL 25 in April 1941. The QSL Push-Pull (June 1940) ran 600 volts on the 6L6 plates and could light a 100 watt light bulb to full brilliance. The 5 watt version described in December 1939 was at the other end of the spectrum. It was a transformerless design using a voltage doubler off of the 110 volt AC line to get 220 volts B+. That particular article mentions that the operator should avoid touching the metal frame of his key. The 6L6 (and its big brother the 807) appeared in transmitter article after article for two decades.

The 1940 QST article mentions "lessons learned" that we can relate to:

• Portable so that it can be hand carried through any place the operator might need to go
• Powerful, selective and sensitive enough to work through interference
• 50 mile range,
• Can be powered off of utility AC power or batteries,
• Include a precut antenna.

I’ve never tried fixing the Hero of Hallettsville and putting it on the air. Any repairs would destroy its character and some of the history behind it. 

 For more on 6L6 transmitter see Gary's, WD4NKA, article at  https://q5letterpress.blogspot.com/2015/02/the-legacy-of-simple-6l6-transmitter.html  

AWA Bruce Kelley CW QSO Party, November 2025

The 2025 Bruce Kelley Memorial CW QSO Party is now in the books. I was (for me) fairly successful with twelve QSOs, mostly in the upper midwest and northeast. I worked no stations to my west or south.

My transmitter was a Push-Pull Colpitts Oscillator  (see https://w0vlz.blogspot.com/search/label/1934%20Colpitts ) running about 6 watts out. I stayed on 40 meters where it sounded the best. Even on 40, though, you can hear some flutter in my signal. This is from the wind slightly blowing my antenna around. This in turn changes the load on the colpitts oscillator transmitter changing the transmit frequency slightly.

Here is a link to a recording of my signal  https://youtu.be/esTWUadIeRk

Bruce Kelley Memorial CW QSO Party

 In a few days this season's vintage radio events continue with the Bruce Kelley Memorial CW QSO Party. This will be two weekends using 1929 transmitters on the air. See https://www.antiquewireless.org/homepage/bk-qso-party-details/ for details.

The last few days I've been testing my Push-Pull Colpitts transmitter on 40 and 20. It sounds pretty good running 5-6 watts out. I'll probably be on 40 in the evenings and 20 in the afternoons.

 

More construction information here:

https://w0vlz.blogspot.com/search/label/1930%20TNT

 https://w0vlz.blogspot.com/search/label/1928%20Hartley

 https://w0vlz.blogspot.com/search/label/1934%20Colpitts 

73,

Niel - W0VLZ

 
 

Putting a Late 20's/early 30's Ham Station on the Air

On January 1, 1929 new US communications regulations took effect that supported the outcome of the 1927 International Radio Conference. Hams now had only a small percentage of the spectrum. In order to avoid interference their signals had to be harmonic free and clean with little FMing, drift or AC note. The ARRL estimated that only about 10% of the existing stations could meet these new standards. Many pages of QST were devoted to helping hams get ready for Jan 1, 1929.

I've assembled and used a station that reflects the state of the art during this era. The transmitter is a two tube TNT (tuned plate - not tuned grid) while the receiver is a National SW3 three tube regen. It is usable on today's ham bands.

 

Video: https://youtu.be/sijUooylq_U

• Station Overview: 0:0
• TNT Transmitter: 1:46
• National SW3 Receiver: 4:40
• Station Tuneup: 11:20
• On The Air: 16:24

AWA 6AQ5 Transmitter (continued)

 

At https://youtu.be/nJgJenvi2x4 I've posted a demonstration video of an entry/novice station as it might have existed in the mid 1950s running on 40 mtrs. It uses a National NC-57, a receiver that was introduced in 1948. The transmitter is my single 6AQ5 running 6-8 watts out. For more information see the video description.

AWA 6AQ5 Transmitter (continued)

 I've gotten the power supply built into my 6AQ5 transmitter. I used an old school PS design: a 6X4 full wave rectifier with a capacitor input filter feeding a 20K bleeder resistor. 

This transmitter is working and sounding fine. Power out maxes out around 6 watts with 15 watts input....a couple of items I can look at 1) calibration of my watt meter 2) the value of my pi network coil. Compared to 8 to 9 watts out 6 is not a big deal. I'll poke around at this issue later 

For now I'm pairing this transmitter with my hopped up National NC57. See https://w0vlz.blogspot.com/search/label/NC-57  .

**** Addendum **** 

Tonight I worked Don , N0DLR, using my NC57/6AQ5 station.  Even with a lot of static we had a successful QSO. The Reverse Beacon Network reported many hits in the North East US with a few more scattered to the south and west of me. My new rig is in the log.

 

AWA 6AQ5 Transmitter

I've gotten the RF portion of my AWA 6AQ5 transmitter ( https://www.antiquewireless.org/homepage/pcb-item-12 ) done and tested on 80, 40 and 30 mtrs. This transmitter sounds nice on 80 and 40 running 8-10 watts out with a single 6AQ5. It doesn't sound quite as good with HC49S crystals on 30 but it is still acceptable. 

The plate tuning and load variable caps are under the chassis. Temporarily I'm running with an external 300 VDC power supply. Eventually I'll add a power supply in the spare space at the rear of the chassis. The PS transformer and rectifier will go on top with the fuse, filter caps and filter choke underneath.

 

The PC Board and parts list from AWA allows for a straightforward semi-kit or homebrew project. My thanks to the AWA for making them available.

 

KC7WXD built one also. See https://www.youtube.com/@kc7wxd

 

Does anyone know when PC Boards started showing up in tube rigs? Were there any before the Knightkit R-100? It used a PCB for most of the components. See its review in the Nov 1958 issue of QST.

 

 

 

Vintage Homebrew

Recently I was asked by the Long Island CW Club to  give a zoom talk about my vintage homebrew projects. The transmitters, receivers and power supplies I discussed covered the late 20s through the mid 50s. My talk, though, wasn't just about recreating some pieces of ham radio history. I also covered the economics, technology and current events that drove ham radio during this period.

My power point charts with my speaker script is at   http://www.wiegandfamily.org/HomeBrewTalk_March25/VintageHomebrew_LICW_31Mar2025.pdf

 

A Siamese Paddle

Recently my local ham radio club asked for members to show off homebrew CW keys. I decided to build something that would fit in with the club show-and-tell and, even better, be usable in my shack.

 

The July 1952 issue of QST describes "The Siamese Paddle". It is two J-38 straight keys mounted on edge and bottom to bottom to form a set of dual lever paddles, great! I didn't have two J-38s but I did find two EF Johnson Speed-X straight keys on my shelf. I could use these for my paddles and still have two original Speed-X keys if I ever decide to disassemble my Siamese Paddles. I also found a couple pieces of aluminum to form the new base and vertical support. 

 

After drilling four mounting holes and creating new finger pieces I now have a new set of paddles.

These paddles aren't a Begali but they are certainly cheaper and my typical CW speed is only around 16 WPM. They work fine for me and fit in well with the rest of my vintage gear.

 

73,

Niel - W0VLZ