Tube (valve) bases?

Hi,

I have an antique radio that I'd like to keep running, but it uses tubes. Besides the other obvious deficiencies of tubes, they are getting extremely expensive.

I've put together transistor circuits to simulate some of the tubes in my radio, but I don't like having to break dead tubes to get to the insides of their bases, and I'd rather not change the chassis. What I want is tube bases that I can put my circuits into, and plug modules into as if they were tubes themselves. Google, etc. give me only sockets and 4-pin bases when I search.

Anyone know where I can get 7-pin, octal (8-pin), and 9-pin tube bases? I once had a set of adapters that brought the pins out to tabs for troubleshooting, but they were expensive, and I haven't seen them for sale for years.

John Perry

Hello John,

You might want to post the question on:

rec.antiques.radio+phono

That's where a lot of the restorers hang out.

Regards, Joerg

Hi John Check on

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I have several times used a similar but faster method.

I find some wires or pins which fit in the holes. I press these pins into the contact through a piece of paper. Then I spread epoxy glue on the paper, covering the pins as much as possible. The glue becomes a solid block, holding all the pins in place. With some ingenuity you can add a strain relief if neeeded.

FANTASTIC! I may even do the octals this way (I'd found some before I asked this group, but in the future...).

I've noticed the ms connector pins seem to be about the right size. I'll have to get some and try them out. Now, where might I find exact specs on the pin sizes...

jp

Some plug-in relays use octal bases and have neat transparent enclosures that you can build your circuits into (as long as they don't get too hot).

You can keep the salvaged relays and use them 'naked' for a different project another time.

Thanks for the help, guys, but I can get all the tubes I want. The problem is two-fold: 1) tubes are expensive and relatively shortlived;

Semis are lower power, lower noise, more stable, cheaper -- what all have I left out?

I can build very good tube emulators for a fraction of the cost of a tube, and they'll last essentially forever. And they're not hot, and consume no filament power.

If I should ever want to get rid of my SP-600JX, I'll get any tubes I need then. BA enthusiasts generally want to be authentic, which is not part of my personality :-).

jp

I wonder if you could get appropriate diameter pins from someone like Keystone, and install them in small circuit boards in the tube base pattern. You'd end up with a little square or round plate with tube base pins sticking out of one side; you could solder your circuitry to the pins or to pads connected to the pins on the circuit board.

Matt Roberds

And when you go, get all the flyers for other hamfests in your area, as they're not all listed at the arrl site. If you don't find everything you need at one hamfest (or even if you do), you may want to go to the next one.

I've seen good selections of receiving tubes for a dollar each at hamfests earlier this year. Older types such as Loctals may be harder to find, but I've heard that even those can be cheap when you can find them. If your tubes' type numbers are just two-digit numbers and have four-pin bases, then those might be more expensive and harder to find.

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After Roger's post, I recalled a post where someone mentioned doing something similar for those round multi-pin connectors popular on military gear. The individual pins come in a few standard sizes, but there are approximately 10**pi different arrangements. He needed to make a mating connector for short-term use while the ready-made connector was ordered. His process was to attach the right size pins to wires and insert them into the connector he had, and then operate the equipment to make sure he had everything right. Once he was happy, he made some kind of "mold" around the outer shell (wax paper?) and squirted RTV silicone in between the pins and the mold. He ended up with a "plug" made of silicone with the pins sticking out of it.

My first thought would be just to use a caliper to measure the pins on some old tubes. If you don't need the caliper for anything else, even one of those $5 plastic ones would probably work well enough.

Matt Roberds

Good! I downloaded the ones I need for now. Thanks.

jp

Perhaps I should pop over to Elec. Surplus (or as we used to call them, "Western Garbage") over lunch and pick up some of those for [the OP] John Perry.

Are you handy with tools? Why not get some phenolic, some stiff wire for pins, some epoxy, and make them?

Good Luck! Rich

You could try

hope this helps

Jay