Grunow - Model 654 | Replacing a Few Capacitors & Resistors | I.F. Transformer Lead Dress Issue

Replacing a few capacitors and resistors before discovering the I.F. Transformers lead dress issue that needs to corrected.
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In the previous episode, preparing to restore this beautiful Grunow (General Household Utilities Co.), Model 654, Chassis 6N from 1937. The cabinet is very unique being a Table Upright; looks like a mini console covering two bands, i.e., the BC (550-1750) kHz and SW (2000-7000) kHz. The I.F. Frequency is 465 kHz.
The schematic: Riders 8-19, 20.
The receiver tube complement:
6K7G - RF Amplifier
6A8G - 1st Detector/Oscillator
6K7G - I.F. Amplifier
6Q7G - 2nd Detector/A.V.C. & Audio Amplifier
6F6G - Power Output
80 - Full-Wave Rectifier
The playlist for the series:
studio.kzbin.infoP...
LC (Front-End) AM Broadcast Tester - One Chip AM Radio Circuit
studio.kzbin.infoZG_E...
Thanks for watching and subscribing to my channel on vintage radio repair and other related circuits.
#restoreoldradios

[@josephmagedanz4070]

Thanks for the "BED" resistor chart...that'll be helpful.

[@RestoreOldRadios]

You bet! I’m glad you found it helpful. Best, Don

[@jimnewman5596]

I bought that rivet tool a while back after watching one of your videos and it quite handy indeed Don.

[@RestoreOldRadios]

Thank you Jim. Hope this finds you doing well. Best, Don

[@chetpomeroy1399]

Using an engraver is a pretty smart idea for roughing up the surface for a better solder connection! It would be a good precaution to either put some spaghetti tubing over those bare wires going into that IF transformer or just replace them. I've got an RCA 75X14 from 1947 that uses those same types of crumbling rubber insulated wires.

[@RestoreOldRadios]

Chet, the little engraver does come in handy. The I.F Transformers are coming out and I’ll be placing new lead wires on them for sure. Thanks again for following along. Best, Don

[@f.k.burnham8491]

I always have a good assortment of colored heat shrink tubing. When I have crumbling rubber wiring in a chassis, I can with care, just slide the correct color heat shrink down over the wire or up into an IF can which negates the need to replace the wire. All I do is unsolder one end. Also no need to shrink the tubing unless you want to.

[@RestoreOldRadios]

Great point! I’ve done that in the past too with positive results. Hopefully folks following the comments will see this as an option. I decided to rewire them and cleanup the trimmers too. I appreciate you watching and your recommendation. All the best. Don

[@DERB_Seymour_Indiana]

Hey Don. Quite a few caps in this set to replace. Neat tool to remove rivets. Off to the races! :)

[@RestoreOldRadios]

Lots of caps Doug as you noted. So far, all of the leads are wrapped around the tie points multiple times. Looks like the coil method will be used often. Best, Don

[@hestheMaster]

I have heard that dog bone resistors are usually good but down south the temperature and humidity changes over time make them unreliable. Don't ignore the little 1/4 and 1/2 Watt resistors either, for the same reason. Terminal strip solder points are too shiny smooth and don't accept solder too well. Good idea with using an engraver but emery cloth works too. I bought some at Menard's. Probably will last forever as I don't do plumbing work. Oh no the cursed rotten rubber insulation has raised it's ugly head once again. Been there , done that and seems like way too much of the time Don.

[@charlymgtow294]

Hy from Germany, must i also replace a Mika capacitor? I mean those flat plastic capacitors with dots. Are they very durable or do they always have to be replaced? Thank you

[@hestheMaster]

@@charlymgtow294 They are a very low capacitance and usually don't cause problems. Mica caps pretty much are stable even as old as they are.

[@RestoreOldRadios]

Great information Steve. Only one resistor to this point was found to be in tolerance. Even the 1/4, 1/2 W resistors have degraded significantly over time. Good tip on the emery cloth. Best, Don