Seems like I will NEVER learn.

View previous topic View next topic Go down

Seems like I will NEVER learn.

Post by Wildcat445 on Sun Apr 19, 2015 9:30 pm

I have started my yearly radio collection tune-up.  This is where I operate every radio and item of electronics I own, check it for little problems like dirty volume controls, correct anything I find, then clean the chassis and cabinet and check for possible live critters, like spiders (  affraid ), meeces, things like that.  No living critters were found.

All was going swimmingly until I came to a Truetone 2637.  This is not the prettiest radio I own, but it has a teal and white plastic cabinet with dark red knobs.  It is officially deemed "cute" so it is in the frau's "collection."  It has a 6-tube chassis, was built my Wells-Gardner, and has traditionally been a powerful performer.  I fired it up this afternoon, and got nothing.  Just a little hiss from the speaker, but not much of that.  Dead as a two dollar mule.  I whacked the cabinet with my hand and still got nothing.  

I dutifully pulled the chassis, stood it on end, and clamped it to the edge of the bench with Vise-Grips.  I plugged the chassis into my Variac/dimbulb/ iso trans contraption and flipped the switch.  Everything lit, pilot lite lit, the radio played just like it should.  Good volume and sensitivity.  It could not have played better.  

So I unhooked the power cord, released the clamp and laid the chassis down on the bench to have a peek.  Nothing looked amiss.  I did a short test on all the tubes, and they passed.  So I plugged the set back in, turned on the PS.  The tubes lit, the pilot lite lit, but the thing was dead as before.  Nothing.  I took a wooden brush handle and started whacking various components on the chassis.  I whacked the tuning cap and the radio came to life.  In about ten seconds, it popped, and went dead again.  I whacked the tuning cap again, it came alive again, then died.  

So if I stand the chassis on end, it will play fine.  When I lay the chassis down flat or install it in the cabinet it won't work.  Out of sheer desperation, I connected a jumper wire from the frame of the tuning cap to the chassis.  The radio played fine.  Remove the jumper wire "ground" no radio.  I started moving the tuning knob and wiggled the tuning cap.  I could get the radio to quit without the jumper, but with the jumper the radio would not quit.  There are two bolts that hold the tuning cap to the chassis.  There is a fiber block under the tuning cap.  The only "ground" provided on the tuning cap are those two bolts.  To prevent my having to unsolder the wires and restring the tuner, I removed the bolts individually, polished them on the wire brush on my grinder, then used sandpaper to clean the area where they contacted the chassis, followed by a squirt of WD-40.  This seems to have taken care of the situation.  There must have been some corrosion that prevented the tuner from contacting the chassis properly.  I reckon when I stood the chasssi on its end, something must have shifted enough to restore the ground.  Fortunately, it was a simple problem, but it had me scratching my head for a while.

WC

Wildcat445
Member
Member

Number of posts : 5286
Registration date : 2011-09-19

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Bill Cahill on Mon Apr 20, 2015 10:11 am

Is this an ac dc set? Yikes. B- to chassis??

_________________
Please also join us here;  http://videokarma.org/index.php
avatar
Bill Cahill
Admin
Admin

Number of posts : 4585
Age : 66
Registration date : 2008-03-12

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Wildcat445 on Mon Apr 20, 2015 1:05 pm

B- is to common negative, which is one side of the power switch.

WC

Wildcat445
Member
Member

Number of posts : 5286
Registration date : 2011-09-19

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Bill Cahill on Mon Apr 20, 2015 6:11 pm

But, does B-go directly to chassis??

_________________
Please also join us here;  http://videokarma.org/index.php
avatar
Bill Cahill
Admin
Admin

Number of posts : 4585
Age : 66
Registration date : 2008-03-12

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Wildcat445 on Tue Apr 21, 2015 12:56 am

No, sir.

WC

Wildcat445
Member
Member

Number of posts : 5286
Registration date : 2011-09-19

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Bill Cahill on Tue Apr 21, 2015 10:57 am

Is there a capacitor going from B- to the tuner?? If so, you are shoring out the tuner capacitor to B-. There should be two capacitors from B-. One going to tuner, unless it's directly connected to
b-, which I occasionally see, and, the other from B- to chassis.
Most tuners, now, I said MOST tuners in ac dc sets don't go directly to chassis.

_________________
Please also join us here;  http://videokarma.org/index.php
avatar
Bill Cahill
Admin
Admin

Number of posts : 4585
Age : 66
Registration date : 2008-03-12

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Wildcat445 on Tue Apr 21, 2015 12:11 pm

This one is insulated from the chassis. Yet the only way it will work is to connect a jumper from the frame of the tuner to the chassis. You just brought up a good point. I missed what you were asking. The light finally came on. Rolling Eyes

I am missing something. I do not see a cap to B- from the tuner. I occasionally see a strap from the tuner to the chassis, but this one does not have one. What I did was to remove the mounting bolts, one at a time, and cleaned them up. What I did apparently connected the tuner to the chassis somehow. That seems to have fixed it, at least temporarily. I need to pull the schematic on this thing and see what is supposed to be there. The radio has always worked well until I fired it up for its annual inspection. It does not get used much. There is a cap from B- to chassis. You've got me to thinking. I need to revisit this radio and see if I have overlooked something. Just because it was working does not mean it was working RIGHT. Thanks for the input, Bill.

WC

Wildcat445
Member
Member

Number of posts : 5286
Registration date : 2011-09-19

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Bill Cahill on Tue Apr 21, 2015 1:01 pm

YW.
I gave up on one collector today because after all the help I've given him on repairing his TV's, he insulted me with name calling. He refuses to apologize for the name calling. Let's see what happens next time he needs my expertise on a tough tv issue...
He owes me a chassis he doesn't want, and, now, refuses to ship it.
And, these are the kinds of friends I want?? I don't think so......

_________________
Please also join us here;  http://videokarma.org/index.php
avatar
Bill Cahill
Admin
Admin

Number of posts : 4585
Age : 66
Registration date : 2008-03-12

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Wildcat445 on Tue Apr 21, 2015 1:11 pm

Manners via electronic communication sometimes become muddied. It is really hard to sometimes remember protocol when one is having a problem. Old-timers like me are sometimes more interested in the project than we are about the person's feeling who we are trying to direct. And we get our feathers ruffled when we don't get the respect we feel we deserve. You have a wealth of information in your head that most people, myself included, wish they had. I know beans about a TV, other than basics like changing caps and that. I would certainly encourage you to not withhold the resource you possess that is unavailable to learn otherwise for any amount of money. Without guys like you who are willing to help, the rest of us would be SOL when it comes to fixing old TV's. Thanks, Bill, I appreciate your input.

WC

Wildcat445
Member
Member

Number of posts : 5286
Registration date : 2011-09-19

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Bill Cahill on Tue Apr 21, 2015 1:28 pm

I realize I may also have taken him wrong. But, he just plain got nasty, ignored my earlier apology, and, continues the insult today.
If he would apologize for the nasty names he called me, that would be one thing. I don't need friends like that. I am always willing to share my knowledge with people. I've learned at the best school there is. T S O H K.
Short for the school of hard knocks. A lot of old timers didn't want to spend their time sharing their knowledge with me, so, at an early age, I decided I would learn everything on my own. I'm still learning. That never stops. About the time you think you've seen everything, that's when a new one comes up. Add old age of equipment, and, abuse to that, and, it adds an interesting curve to electronics repairs.

_________________
Please also join us here;  http://videokarma.org/index.php
avatar
Bill Cahill
Admin
Admin

Number of posts : 4585
Age : 66
Registration date : 2008-03-12

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Bill Cahill on Tue Apr 21, 2015 1:31 pm

I swear if our old things could talk, boy, would we hear some interesting stories!!!!

_________________
Please also join us here;  http://videokarma.org/index.php
avatar
Bill Cahill
Admin
Admin

Number of posts : 4585
Age : 66
Registration date : 2008-03-12

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Wildcat445 on Tue Apr 21, 2015 2:16 pm

I'd go along with that, Bill.

WC

Wildcat445
Member
Member

Number of posts : 5286
Registration date : 2011-09-19

Back to top Go down

Re: Seems like I will NEVER learn.

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top

- Similar topics

 
Permissions in this forum:
You cannot reply to topics in this forum