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37-84 No RF after overhaul
#1

Hello all. 

I'm trying to bring a customer's 37-84 back to life. (schematic attached) Originally it had the typical hum and would tune no stations. After a complete recap the hum is much reduced, but still no RF what so ever. The radio itself is in very good condition with no work performed on the chassis. I have: replaced all caps, out of spec resistors, checked all tubes, extensively checked continuities with no luck.  All voltages are dead on. Resistance and voltage across the FC is perfect.  I have tried applying the antenna to 77 tube grids with no effect. I'm stuck !!!!

There is one section that does seem odd to me. There is a parallel capactor and resistor (6, and 7) I would assume there to create bias for the 77 tube. However, there is no voltage of any kind across them. Nothing , nada, zip.  This doesn't seem normal. 

Unfortunately, my signal generator shot craps so I am awaiting a new one. Any suggestion where I might look next in the mean time.  I do have replacement 77 and 42 tubes on the way and I'll give that a try. 

Thanks Steve


Messages In This Thread
37-84 No RF after overhaul - by spierce328 - 12-30-2018, 06:31 PM
RE: 37-84 No RF after overhaul - by Radioroslyn - 12-30-2018, 07:34 PM
RE: 37-84 No RF after overhaul - by spierce328 - 12-31-2018, 12:29 AM
RE: 37-84 No RF after overhaul - by Radioroslyn - 12-31-2018, 02:20 AM
RE: 37-84 No RF after overhaul - by spierce328 - 12-31-2018, 04:58 PM
RE: 37-84 No RF after overhaul - by Radioroslyn - 12-31-2018, 07:18 PM
RE: 37-84 No RF after overhaul - by klondike98 - 12-31-2018, 07:27 PM



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