60's Zenith, next step?
 

Hi all. I just picked up an early 60's Zenith with stand and owners manual and need some help with it. Model #K2127 Chassis #16K27T. It's portable with a strap handle on top. It's VHF only, has a volume knob below tuner that doesn't seem to have provision for on off. It has 3 adjustment knobs on the side and another big knob. The woman said that was the "wind up knob" and from what she described from her childhood memeories of this tv, to me it seems like some kind of timer.

I couldn't plug it in becuase the cord was severd at the point where it entered the tv. She says she last remembers it working in the late 70's and her dad may have cut the cord so no one would use it' To me it looks like it was flexed too many times and simply frayed.

I popped the back off and it was dusty, not rusty. the 5 amp fused looked good. The 3 big tubes, one RCA and two Zenith had a black spot on the inside on one side.

Bear in mind i'm pretty handy with home and auto but a complete newb to tvs.

My first thought was fix the cord and let er rip, but I think I should address the tubes first, no? If they were light bulbs or fuses, I'd see those black spots as evidence that they were junk. Is that the case? are they available? If so where and what's a good price to pay?

Also, any other info about this model?

Thanks guys.

Al

The black spots are fine. These are "getter flashes", placed there to absorb stray gases inside the tubes. A silver or black appearance is normal. Any that have turned white are a sure sign of a bad tube.

If the set hasn't played in decades, it likely needs a bunch of capacitors replaced. A real thorough going-over before just turning it on is a good idea to prevent damaging parts like the flyback or power transformer.

At the very least, bring the power up slowly with a variac, or use a "dim bulb" type series lamp setup to limit current during initial testing.

That's one of Zenith's finest examples of bulletproof consumer electronics from 1963.

That is probably a sleep timer on the front. some of those paper caps are potential troublemakers.

It should really be OK to power up as is..... but use a variable supply to bring it up slowly as N2IXK says.

Nice find. Those were among the best sets ever built.
Practically immortal. It would be best to bring it up
slow with a variac or light bulb.
The on/off on most Zeniths are on the volume control
usually push-pull. I dont remember but the sets with a
timer may not have had one. To clean out the dust use
a soft brush & your compressor. Just dont blow away any
tags & keep the nozzle back a ways. The cord is common
but unpolarized, a polarized wont go on. Cant wait to see it going
again, there are a bunch of us ready to help you along.

73 Zeno:smoke:

Awesome! Thanks for the info. I do believe I have something to power it with. And an old am radio that the gave me with the tv has a detachable cord that'll work perfectly.

Finally have the day off tomorrow so I'll dig into this set as well as my Chromacolor.

I'll keep you posted.

Al

Ok, spent some time on the 63 today. I rigged a living room light/cieling fan dimmer to a power strip to fire it up slowly. The rig worked great and the power up was nice and easy. Unfortunately by the time I hit full power I got white noise but no snow at all, just a dark screen. Once it ran for about 10 min I plugged it right into the wall. I tried hooking my DTV converter to it and did get sound of varying quality (buzzy). I tried messing with the common controls in case someone put em way out of whack. Nothing.

I tried poking around gently with a pencil for loose wires etc. No change. i did notice a very small flickering white light at first from the lower right "circuit board" area behind one of the big tubes, but that seemed to go away. Also there is a "collar" on the slim part of the picture tube just before it widens. This piece looks a little crusty, not falling apart, but seen better days. Other than that, didn't notice anything burnt, frayed, disconnected etc.

Up to this point I've only given it a superficial cleaning, have not taken anything apart yet.

Al

First a few cautions.
One of the tubes has a "plate cap" on top. Its old & dried up
so it can break off but you usually can fix it.

The pix tube socket also is dried up. If you take that off be sure
to hold the bakelite end of the pix tube while slowly rocking off
the socket.
I do not have a manual for this set so I got one from a year later.
Much is the same BUT there may be major differences.

Odds are you have no HV. The 4 tubes that can cause it are
6GV5 horz output
6GH8 horz osc
6AY3 damper
1K3 HV rectifier ( in the cage )
The crusty part is the yoke. It can cause no HV. Most bad yokes get
crusty black but not all crusty yokes are bad. Listen for hissing.
Often if you pull a bad yoke off & run the set it will be burning
on the INSIDE. If you try this leave the pix tube socket off.
See what you find. Also see if you can find that white light.
You may want to give it a visual underneath, the bottom comes
right off.

73 Zeno:smoke:

Ok, thanks.

I checked it again today before logging in and all the tubes light up to some degree as does the small "bottleneck" end of the picture tube.

The yoke isn't black, still whitish but crusty none the less.

How can I tell which tube it is? Do electronics stores still test tubes. Are replacements available? $$??

I didn't see the white light today but I will turn it over and pop the bottom off to look anyway.

Thanks again.

Al

I dont think you will find a tester in a store anymore. Also
they are not 100% right. You can still find NOS tubes,
some are not cheap. The light you saw may have been one
of the tubes shorting out, you can lightly tap the tubes while the
set is running were you saw it & see if it happens. If it does the tube is
bad & probably the problem.
Ive never seen a whitish yoke. Any chance the wires are covered in CuO2 ?
If so its not long for this world.

73 Zeno:smoke:

If the light came from inside the damper tube then grab a replacement. I've got one of the previous generation and a newer one that might have the same chassis. On the older one the original damper was arcing intermittently which was causing the HV to come and go until I replaced it...

You can seek out someone in a local antique radio collector club with a tube tester.
The tubes in your set should be reasonably affordable. IIRC the only expensive TV tubes (ignoring CRTs) were the horizontal outputs of color sets (which are about 25$ these days) which CB radio enthusiasts depleted long ago with their illegal homemade transmitter boosters which ran the tubes beyond their specks thus eating those tubes like candy.

Ok, thanks.

The light was behind/between the two bigger tubes to the right of the picturet tube when viewed from behind, I haven't taken the bottom off to investigate yet.

Would it be a bad idea to buy one of each tube and replace one buy one til the set works. Then I'll have spares for future use.

What's Cu02? What color is the yoke supposed to be? I said whitish, could be described as off white, tanish. Kind of like old plastic that yellows with age. Def not black. In any event, if it is junk, whats the best course of action?

Thanks.

Al

Google deflection yoke & there are tons of pix of normal ones.
Most of them are newer style from color sets but it will give you
the idea.
CuO2 I was thinking copper rust on the windings.
As far as tubes go its a gamble. You gotta decide how far to &
how deep into the hobby you want to jump. A good step
would be to get a few "how to" books from the 60's, a big library
may still have them. All TV's from that era are pretty much the
same so it would be a great help.

73 Zeno:smoke:

Thanks Zeno.

I did lots of cleaning and some more poking around. Turns out what I thought was the yoke was just a balck plastic covering for some wires half way between small end and big end of picture tube. Yoke is nice shiny copper and rest of set looks really good inside after cleaning.

Removed bottom panel and found source of white light. There are brown strips with metal plugs pressed in and various diodes etc soldered onto the plugs. Between two plugs it appears that something arced there and now there is a small hole burned clean throught the brown strip. Electricity can be seen arcing in the hole with the set on. My first thought was that the brown strips were like printed circuits and that I should put a bit of solder there to enable the flow of electricty. Now I'm not sure.

Should I sever the strip to stop the wayward flow of electricty, or solder it to enable the flow.In any event I hope that's the cause of my trouble.

Not sure how far I want to go but I'm having fun playing around. Course not as much fun as I'll have watching it.

I'm at the library now on thier pc. I'll look around for some of those books.

Btw, thank you all for your help thus far. Means a lot.

Al

Cut out the burned part. May be all thats wrong OR it may be burning
for a reason. Hopefully some water got on it. Also be sure there is
nothing laying on tho like a loose screw.

73 Zeno:smoke:

Thanks Zeno.

Come to think of it, when I tipped it over to get a better look at the burned area, a screw did fall out from somewhere in there.

Btw, that black plastic cover that I though was the yoke was covered in white residue initially making it seem more crusty. Cleaned up with damp cloth and elbow grease.

Snow storm tomorrow. I'll work on that burned out strip and keep you all posted on Thurs. Thanks again.

Al