[Robbie Roberts]

Chuck, and all, If I were to replace, say, a .05mfd capacitor, with perhaps a .0047 rather than a .047, such as at locations 6, 13, and 15 in my Ant. and RF sections of the subchassis, would they work for a bit, then give me the problems I am experiencing?

Seems I may have done just that... I appear to have added an extra "0" to the numbers I needed for these condensors, and so have been operating with the wrong values. I just pulled the RF subchassis apart to check switches and coils per Chuck's suggestions, and noticed the new pieces I picked up(which have correct numbers) as spares, in case I needed to replace them this time, were a good deal larger than what I already had put in there: thus I went back and checked my original notes, and discovered my error...

I just went back to my notes, and bills for parts, and confirmed my error...

Never write stuff when tired!

I will be waiting for confirmation of my theories here...

Thanks
Scott(who feels stupid. er)
Well, anyway, I am learning LOTS of GOOD LESSONS for next time!
Arrrggghhhhh!!!

[Chuck Schwark]

Most probably. Cap 15 is the RF tube plate bypass cap on the B+ line.


Caps 6 and 13 are on the AVC buss. Cap 6 is for bypassing and cap 13 is the time-constant/filter cap in conjunction with resistor 34.

They "filter" out the audio freqs on the AVC buss which is only the DC component of the deteced signal. Too little filtering (or too short a time-constant) lets the AVC buss "bobble" up and down in time to the audio causing wild gain shifts making the detected signal jumpy which again makes the AVC buss even more jumpy, etc....

[Robbie Roberts]

Thanks, Chuck! Think anything else down the line might have been damaged that I should look for? I was planning to replace the resistors and the two mica caps in the RF subchassis(which have already been replaced once) but if the 6,13, and 15 caps are the issue, I might not- unless you think there may be good reason to...

Thanks!
Scott

[Chuck Schwark]

Always fix one problem at a time.

If those parts are already changed once, leave 'em alone. Just be sure they are the correct values too.

Those three bypass caps being only one-tenth the size they need to be is probably 95% of leftover problems you have right now.

[Robbie Roberts]

Chuck- I went through and looked over all the values obtained... I am certainly learning from my mistakes...

Always "read" resistor codes when received
Always double check values to be ordered twice before ordering, and again when received.
Don't get your bare arm too close to a nicely warmed tube.(That one didn't need much discussion...)
Keep pointy tools, such as solder picks, away from where they might puncture speakers. Alternately, keep speakers from where they might get punctured, or make a cardboard protector plate.


I'm still populating the list, but the next radio should go smoother!(I have to recap a simple Motorola for my best friend- payment for the 46-1203 he gave me...) Then I have to decide which radio to tackle next, while I listen to the 37-650 playing...

Scott

[Chuck Schwark]

Welcome to The Explative Deleted Club.

We've all been there at one time or another...