rca 19K low volume

[sddave]

replaced 5 of the domino ,s and up running strong,

so did you get the audio to work nicely?

 

[gadget73]

I gave him a digital copy of the service manual I have on file in post #14. So eventually he will get it. Still strange why someone would stick those vintage mica caps in other than it might trick someone into thinking it was original and increase a non existent antique value when the cabinet is the antique value of it.

I wonder if they were the right value. 5000pf / 0.005uF is awful big for mica. Excessively small will make for problems. I'd buy that as a more likely explanation than they were actually bad. Unless they weren't mica and were those crappy paper caps that Micamold made in the same form factor. Those are pretty much always bad, like any other paper cap. I've very seldom had problems with actual mica caps.

if one wanted the whole "looks original" thing the usual route is to re-stuff the paper caps. Thats actually not very difficult, and looks a lot more correct.

 

[sddave]

I wonder if they were the right value. 5000pf / 0.005uF is awful big for mica. Excessively small will make for problems. I'd buy that as a more likely explanation than they were actually bad. Unless they weren't mica and were those crappy paper caps that Micamold made in the same form factor. Those are pretty much always bad, like any other paper cap. I've very seldom had problems with actual mica caps.

Its the reason why it raised some alarm with me on it. Plus I've have had units come in where they bought it at an antique shop and they threw in whatever random value in. MDE or MKP film caps is what could have been used where 0.005 uf or 5nF caps were and really, the only ones in pF (which was called MMF back then) could have been mica. But I told him to measure them to make sure they are the correct values because a 470pF cap as an audio coupling cap isn't going to work well in a place of the 5nF cap. Some of those 60-100 year old electronic parts are ok to use but for others I would pass and get new due to shelf life. Like I wouldn't use period carbon comp due to their fire hazard they posed and used modern ones in some places and non-inductive wire wound in other places instead. Some people dig using metal films but I rather not in these point to point eyelet due to lack of mechanical strength of the leads. Plus I think metal film resistor tend to have a sterile sounding characteristic when they are used exclusively in a tube circuit.

 

[steve1a]

so did you get the audio to work nicely?

yes working GREAT , thank so much for takeing the time to help me out,