[MRCA] Working on an old BC-342

[David Olean]

About 2 or 3 years ago I bought a slightly re worked BC-342 at Gilbert, 
PA and just got around to trying it out. Lo and behold, it actually 
worked. On closer inspection I found that it had issues. The cursor in 
the frequency window was made from a chunk of #12 copper house wiring!  
I forget who sold it, but the price was right and I figured it would be 
fun to get it going. I read two nice articles about the BC-312/342. Mine 
has the RA-20 AC supply and it had sensitivity at about 2.5 microvolts 
for maybe 10 or 15 dB S/N ratio. According to data that i saw, it was a 
bit deaf. It also overloaded and the oscillator pulled on strong 
signals. I figured that the AVC was probably messed up. I then read that 
there were a few Micamold paper caps inside the RF coil compartments. 
Getting them out of the RX is a chore requiring some serious un 
soldering, but I bit the bullet and started on a re build.  Yes there 
were Micamolds in the RF compartments, but when I looked in the IF cans 
I found 0.01 MFD mica caps that had absolutely no leakage.  The article 
that I read in Electric Radio mentioned paper caps in the IF cans too. I 
did not see that and left the mica caps in there. So I have been 
swapping out the paper caps in the LO and all of the RF and the 1st 
detector stages. Each and every paper cap was quite leaky, so I am glad 
I dug into it. That leaves the metal encased bypass caps left to deal 
with. My plan is to use a big (I mean BIG) soldering iron and gently pry 
off the tops of each can and then dig out the guts, replace with new 
mylar caps and then re seal the cans. I read that someone tried to open 
them with a gas torch and almost burned down his house as the oil caught 
fire.  If I can't pry open the caps, I need a Plan B. Is there a good 
way to replace those metal can caps and still have it look sorta original?

73

Dave K1WHS