Tram Diamond d201 Vox recap/restoration thread for dummies

[W4KVW]

I have decided to go with replacment multi section capacitors to simplify the process. My first question Is can I use this 20 20 20 20uf 475v In place of a 10 10 10 10uf 450v. I want the extra voltage rating to protect against the start up surge that Nomadradio warns of.View attachment 61617

You can go higher but never lower in value.I have seen it done hundreds of times because that's all that was available & I have never heard of any issues.I am not an Expert but I know what I have witnessed for a very long time.

SIX-SHOOTER
W4KVW
WRMX520

 

[Enterprise312ok]

I have only been doing this stuff for about a year but this old capacitor looks backwords to me. Am I right?

 

[nomadradio]

Nope, pretty sure that one is C424. It's a 1uf part that smooths out the negative-polarity AGC voltage. A filter cap, but not for a power-supply voltage, but the negative voltage that controls receiver gain.

73

 

[Rwb]

great to see older radios rejuvinated

 

[Enterprise312ok]

great to see older radios rejuvinated

Yes, I am blessed to have the opportunity to learn from some great techs and operators. A special thanks to Nomad and all the other great members on the site that have helped me along the way. Also a special thanks to Jason Lawrence Of Eldorado cb in webers falls oklahoma who has given me the opportunity to work on radios in his shop, and has tought me so much about radio repair.

 

[Enterprise312ok]

New line to ground safety capacitors installed.I may also install a metal oxid varisistor but I am not sure if it is needed.

Next I will start replacing some crispy resistors.

 

[Rwb]

Yes, I am blessed to have the opportunity to learn from some great techs and operators. A special thanks to Nomad and all the other great members on the site that have helped me along the way. Also a special thanks to Jason Lawrence Of Eldorado cb in webers falls oklahoma who has given me the opportunity to work on radios in his shop, and has tought me so much about radio repair.

webers falls,i was there when that barge hit the bridge. got my load of fertilizer n took a back trail out to where i was going

 

[Enterprise312ok]

webers falls,i was there when that barge hit the bridge. got my load of fertilizer n took a back trail out to where i was going

My Mom and sister drove over that bridge about 30 miniutes befort the barge hit, close call.

 

[bucketofguts]

I am starting the same on #13561. Wow what a big help this is going to be.

 

[nomadradio]

I have developed a fondness for the IEC power socket.

Especially the ones with a noise filter attached.

The ones rated for only 3 Amps are not expensive if you shop around. Upside is that if the customer loses his power cord, a new one is as close as the nearest Office Despot store.

Just got in the habit of upgrading the 2-prong cord. The later 3-pin socket is a problem, nobody sells the cord to fit it. More than once we'll see something like this. A new socket is the only safe solution.

This can be a bit laborious, cutting the hole. I cheated and bought a Greenlee punch back when they were under 300 bucks. It's still paying for itself.

73

 

[Rwb]

My Mom and sister drove over that bridge about 30 miniutes befort the barge hit, close call.

they must had god driving them. that was a terrible thing

 

[bucketofguts]

I need some good pics of the concrete resistors. Mine has them a little screwy with 2 twisted together going straight up. Any help would be very nice. That mess and just a few resistors is all that has been done to mine. Valves of course. Thank you.

 

[nomadradio]

concrete resistors.

They are wirewound types. The body is ceramic, not concrete. Not that it's a big deal.

Which version of the radio do you have? The original open-chassis version with the VOX feature? Or the later one with all the small tube sockets on circuit boards?

Big difference.

73

 

[bucketofguts]

They are wirewound types. The body is ceramic, not concrete. Not that it's a big deal.

Which version of the radio do you have? The original open-chassis version with the VOX feature? Or the later one with all the small tube sockets on circuit boards?

Big difference.

73

13561 1st version with vox. Point to point. The rat's nest. Thanks for the come back!

 

[bucketofguts]

Using a ceramic disc cap for C700 creates the risk of discovering a "microphonic" capacitor. Not in the sense of picking up noise, but emitting a 'buzz' in step with your voice level heard inside the radio. Tram used the plastic film cap because it won't make any noise. The ceramic dielectric in most disc caps can become a tiny piezoelectric loudspeaker, vibrating with the amplitude of the RF passing through it, making noise from your voice audio.

Never did figure out how to predict which disc caps had this bad habit. Just learned to use a film cap like the factory did, but with a higher breakdown-voltage rating. They stay quiet.

73

You have a pic of that C700 where the film cap goes? 73 come back...