Restoration of Tube Type Ham Radio Equipment

Well, it happened again. I now own the same model RL Drake T4Xb Ham radio transmitter, and R4b radio receiver, that owned 12 years ago, a circa 1968 tube type communications radio. It is a fine radio, well engineered and together with it's matching receiver, speaker/power supply, and microphone form a very useable Ham Radio Station. Many of these fine sets are still in daily operation. Many people comment that people sound warmer and clearer with tube type radios.. I just know that radios that glow in the dark are part of my life, and I feel obligated to keep fixing them and selling them to someone else, and taking the money to buy another radio.

I have owned the same make and model equipment previously, and retained the operating manual, and some spare tubes. I decided to take the cabinet off, and investigate the condition of the radio. The units do not have any gross dents, scratches, and likely have not been owned by a smoker.

So far so good, I found the top of the chassis to be clean, and not much dust. I looked under the chassis, and observed that all the switch contacts, fixed and wiper, were "Black" with oxidation.
The wiper scraped against the switch contact, but no visible disturbance in the oxidation.

There is only one way to proceede, I will obtain some TARNEX, Denatured Alcohol, and DI-OX5 contact cleaner. Some "Q-tips" will spread the TARNEX across the switch sections, and when that is cold, some denatured Alcohol will be sprayed over the solution. After a day drying, the special DI-OX5 solvent/cleaner will be applied with clean "Q-tips" and left to dry again.

After this happens, the radio/power supply will be plugged in, and the tubes will warm up for a minute or so. A dummy antenna, microphone and morse code key will be attatched and testing will start. After normal warm-up, the operational instructions will be followed and the
tune-up procedure followed.

If I am lucky, it will respond properly, and the meter will respond to the tune-up instructions. We shall see. If stages do not properly respond, the set will be unplugged and the tubes tested.

The next step is to apply some cleaner- lubricant to the volumne controls and other controls/switches so they may glide across the conductive surface of the electronic component.

It will be monitored in a nearby radio receiver for quality, and checked for upper and lower sideband voice quality. Then the morse code key will be connected and away we go.

Voice peaks should be noted on the plate meter, in relation to the sound of my voice. The usual observation looking for smoke rising from the chassis is always noted. When this radio is working properly, a pleasant communications quality radio signal is transmitted. The exact tuning instructions will be followed, and the proper fuses will be in their holders, along with the proper dial lamps.

It has the ability to transcieve with the addition of the Drake R4B receiver, that can h listen to the very same frequency that I am transmitting on. Conversely, it can receive voice signals and place the Transmitter on the same frequency, allowing voice communications. Cables from the back panels of the transmitter and receiver interconnect them.

I will use a vintage desk or hand microphone that has already worked for me since the 1960s with several other radios. Some aquired skill will allow me to tune in the voice signals and to
tune the transmiter correctly, resulting in almost 100Watts of output power. A tired WW2 vintage morse code key will also be part of the communications too.

A combination of tubes and a few transistors will do their respective jobs, and it will be fun to communicate again. A pale green light is behind the analog dials, with a slight change when the transmitter starts.. Continued visual inspection will be useful, and notes taken.

I own modern digital radios too, they are computerized, dependable, and run off 12volt batteries during emergencies.. The tube radio needs a generator, or solar panels with inverters to simulate the generator.... and has allowed the radio to operate when the AC power is missing from the socket.

After a few minutes, of warm up, and listening to the interconnected receiver, it is time to find
others to talk to. Voices with accents around the world, crisp morse code characters, and the
magic of intelligence impressed on a radio carrier, passing through the ether...

Well, I will let you know how the radio works if at all in a few days, some parts are to be ordered, and some references reviewed.

Real radios glow in the dark..