I have cleaned the original relay in several TR-4Cs without
success, Tom. Gary, K4OAH sent me the info on a fix.
You can get a plug-n-play replacement
that has gold contacts and works well for $17 plus
shipping from:

P&B R10-E1-Y4-V2.5K.

Hi Gang,

Yes, that's what's in there now... I knew it was fairly new.
Digikey carries them also for about $16.

Anyway went back in and started to get some pin voltages on the Vox
circuit tubes... stupid me got a small shock ( not use to these tube
rigs! ) and went to repull the relay.

Had prev cleaned them and this time found a sheet of wet/dry paper 1000
grit... fiq I'd gently redo the contacts ( hell the relay is cheaper
than tubes! ).
While it was out I ran the relay by an outside power source... looked
like one or two of the contacts were mis-aligned... fiq I could get
another so I put on the Opti-visor and reset to what looked like the opt
setting for both contacts.

Well darn if it seems to be ok now! I'll put a relay on order but for
now after 2 1/2 hours its been FB

Happy Holidays
Tom aa2vk