[Geoff]

Yes, I have the variac in there set to 110V.  The only reason it is in there is because I never got around to adding a dropping resistor in series with the line cord.  I'll need to do that some day   .

[Ron Ramirez]

Well, crap...I declared victory too soon, it appears.

Yesterday evening as I was showing off the set to Debbie, it suddenly developed this problem of cutting out as the set was tuned.

Now, if I turn the tuning knob a little bit on either side of my SSTRAN frequency (660 kc), it cuts out badly and loses all signal - the tuning eye opens up to indicate a "no signal" condition.

OK...help me out here, people...

[codefox1]

Well, after all your work, it's gotta be something simple, and likely mechanical. So, armed with a dry chopstick and a good night's rest a little poking and tapping should do it.

I'd next fire up the signal generator to find out if the problem is IF or RF related.

Then I would rule out tubes by trying some "known good" spares.

Hope you do not have to revisit coils. Best!

[Arran]

Ron;
  Just out curiousity, does this brand Z set have a copper braid grounding the frame/rotor of the tuning condenser? See if maybe the braid is touching the rotor when it passes by. Alternatively it could be a grid cap lead acting up.
Regards
Arran

[thirtiesradio]

Sounds like something touching the tuning condenser to me, only because it seems to be repeating itself in the same place. I've had that problem before, doing the same exact thing with the eye tube cutting out. Mine also made a light popping sound when it went dead. In my case a small piece of metal that looked like a couple fibers of steel wool had somehow found it's way into the condenser. The radio worked great for a while then acted up when the wire got into the wrong place. It was hard to find the wire. I ended up running a small paper thin piece of flat plastic through the condenser fins while the radio was in the dead spot and finally located the problem.

Best of luck with it Ron.
 

[thirtiesradio]

Yes, I have the variac in there set to 110V.  The only reason it is in there is because I never got around to adding a dropping resistor in series with the line cord.  I'll need to do that some day   .

I can't see the front Geoff, but that set of yours looks brand new from the rear! That is one clean chassis.

[Geoff]

Yes, I have the variac in there set to 110V.  The only reason it is in there is because I never got around to adding a dropping resistor in series with the line cord.  I'll need to do that some day   .

I can't see the front Geoff, but that set of yours looks brand new from the rear! That is one clean chassis.

Thanks.  Here is the thread where I restored my 9S262 that Ron had referred to:

http://www.philcoradio.com/phorum/showth...p?tid=4917

[thirtiesradio]

Yes, I have the variac in there set to 110V.  The only reason it is in there is because I never got around to adding a dropping resistor in series with the line cord.  I'll need to do that some day   .

I can't see the front Geoff, but that set of yours looks brand new from the rear! That is one clean chassis.

Thanks.  Here is the thread where I restored my 9S262 that Ron had referred to:

http://www.philcoradio.com/phorum/showth...p?tid=4917

Beautiful restoration Geoff. It really takes time and patience to take a chassis apart as you did but it sure turned out great! Are you planning the same type of restoration for your 37-116?

[Geoff]

Yes, I have the variac in there set to 110V.  The only reason it is in there is because I never got around to adding a dropping resistor in series with the line cord.  I'll need to do that some day   .

I can't see the front Geoff, but that set of yours looks brand new from the rear! That is one clean chassis.

Thanks. Here is the thread where I restored my 9S262 that Ron had referred to:

http://www.philcoradio.com/phorum/showth...p?tid=4917

Beautiful restoration Geoff. It really takes time and patience to take a chassis apart as you did but it sure turned out great! Are you planning the same type of restoration for your 37-116?

Absolutely. But I'm not sure when I'm going to work on it. First I have to finish up the Philco 640 I'm working on. Then I have a Zenith 6-S-321 that I'd like to get done. I'll probably do the 37-116 after that.

Then I've got:

AEG 3064
Grundig 2035
Hallicrafters s-38E
Heathkit EK-2
Philco 16B
Philco TV, Model 52-T2254
Philco Predicta Pedestal
RCA 128
RCA C13-2
RCA T9-10
Zenith "Bug Eye" TV, Model Z1511BZ

Too many radios and TV's to work on and not enough time in the day.

[sam]

I think this thread has been hijacked

[Eliot Ness]

Ron, I agree with all the previous suggestions:  poke around with an insulated tool (or chopstick from the Ferdinand Wok and Go), gently tap tubes, check grounds, grid caps, tuning cap (including grounds and grommets), etc.  Since this was worked on previously I'd pay particular attention to solder joints that you did not redo also.  Good luck and keep us posted.

By-the-way, that's the way it always seems to happen; the radio plays great on the bench for 3 days, then as soon as it's all-together and you're demonstrating or showing it off a problem or intermittent shows up

[Geoff]

Any luck Ron?

[Ron Ramirez]

Well, I pulled it all out of the cabinet, flipped the chassis over and looked things over carefully.

I fired the thing up on the bench and it worked fine.

I did tap tubes (gently) as well as all RF and IF transformers with the insulated end of a small screwdriver while the radio was playing. No ill effects were noted.

So here's what I did, in no particular order:

I found two questionable solder joints, and resoldered them.

I sprayed the tuning condenser out with compressed air.

All of the coil shields are held in place with two nuts (per can) under the chassis. I noticed that one of the cans was missing a mounting nut. I added one. I made sure that all of the nuts were tight.

I sprayed the band switch and the motor switch with DeoxIT.

After all of that, I tried it out again. Worked fine. I even wiggled the tuning knob rapidly as I tuned on either side of my SSTRAN signal at 660 kc. No problems.

In a little while, I'll put everything back into the cabinet again and we'll see how it behaves.

Oh, I found that Lowe's sells 250 foot rolls of brown 18-2 SPT-1 zip cord. So...now the Zenith has new brown AC cord and a new plug.

[Ron Ramirez]

Everything is now back in the cabinet...

[Image: http://www.philcoradio.com/images/phorum...62_036.jpg]

...and it's working just fine.

I let it play for about a half-hour...switched from AM to SW, ended up listening to a portion of Ted Randall's QSO Radio Show on WTWW, 9475 kc...switched back to AM and slowly tuned down to 660 kc and my SSTRAN. It behaved itself just fine. ???

Well, I will probably work on my Philco Tropic 42-788 some more this evening, so I will let the Big Z play during that time and we shall see how it works out.

[sam]

ron
you probably left poor zenith in a room filled with brutal philco tropics