Posts: 1,517
Threads: 240
Joined: Sep 2012
City: West Bend, Wisconsin
(The schematic is in PDF format)
This is a "simple" little 6 tube AM only radio, manufactured by Warwick under the Troubador (not a misspelling) logo. One tube above an AA5. It was a simple straightforward recap. All were replaced except the 3 or 4 micas. Resistors all checked good. Tubes checked good (swapped out with known good ones to be sure).
The audio output section is working loud and clear. Volume is controllable. Loud buzz when touching center tap of control. Traced through the schematic and everything checks out, yet I cannot receive any stations. I get the normal OSC sound as you tune through the dial (louder on the low end of the dial than on the high end), but only at full volume. Did a simple check plate to grid on all tubes and got a buzz through each tube so the signal is going through yet the set doesn't receive.
The schematic is pretty basic. No voltages listed so not exactly sure what they "should" be.
Any thoughts on what could be amiss causing the set not to receive? Terry?
I am only getting a small reading ( .3 or .4 ohms) across the OSC coil, yet when I temporarily clipped in one of the AES universal replacement OSC coils, it made no difference. Tried a new RF coil as well with no change.
Sometimes the simplest of radios can kick your behind the hardest. This is one of them for me!
Greg V.
West Bend, WI
Member WARCI.org
Posts: 7,212
Threads: 266
Joined: Dec 2009
City: Roslyn Pa
Why do I feel like Professor Le Blanc ????? [Image:
http://philcoradio.com/phorum/images/smi...on_lol.gif]
You know the drill. Check to see if you have hv on the plate of the rf amp, mixer, and if amp. Also grid 2 of the 12SA7 and the 12SK7's. I would suspect an open osc coil or if trans if I was just guessing at it. Oh be careful this one looks like the ac cord IS connected directly to the chassis.
You can feed a 455kc signal thru the ant connection and hear if the det/if amp is working.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got!
Terry
Posts: 1,517
Threads: 240
Joined: Sep 2012
City: West Bend, Wisconsin
Got it! I had a sneaking suspicion all along that the OSC coil wasn't working, as I ohmed out both the IF cans and they had solid and even values so I knew they were good. So, seeing there was only a mica cap and two wires connected to the OSC, I disconnected it and installed one of the universal AES OSC coils. It started receiving stations all across the dial right away. Tomorrow night (while you're luxuriating in Kutztown) I will be figuring out how to mount the new coil under the chassis.
And yes, you have become my Professor LeBlanc! No, no, no Missure Benny!!
Thanks again for the nudge in the right direction, my friend.
Greg V.
West Bend, WI
Member WARCI.org
Posts: 4,611
Threads: 51
Joined: Sep 2008
City: Sandwick, BC, CA
Superficially I though that this set may have used the same chassis as a Truetone set I have, made for Western Auto, but that set uses seven 300 ma tubes like a 25L6, 25Z6, 6SA7, 6SK7, etc. so it would obviously not use the same diagram. Set can appear to work even without the oscilator not working, it may actually be osculating but be doing so at the wrong frequency if something is off in the tank circuit.
Regards
Arran
