Brought back a NICE Zenith flat-chassis set !!
 

Brought back a NICE Zenith flat-chassis set from the convention. I THINK it is a 25DC56, or so. it does have the VRT tranny. I LOVE these sets and have not had one in a long time. The cabinet looks nice too. It is still in the van, I will get a few pixs when I take it to my new garage, maybe tomorrow. This is the FIRST one of these I have had in a LONG time, they used to be EVERYWHERE, but lately they seem rare.

Sweet! Good to see another non-Avante example saved. I bet those like we have will end up being the rarest in the coming years.

First pictures::

These are NOT real good--it is still in the van, but I wanted to get something to show everyone.

I could not get a good angle. WIll get a good pix once it is in my new garage.

Lucky find...that's a clean one!

I remember seeing that set, it was about as perfect as you can get!

The last one of these I had ANY chance to get--was some years ago, about 10 miles away from here. I COULD have gotten it without getting accosted maybe...BUT the cabinet had been trashed, the back cover was missing, the chassis had been smashed up and the tube was shattered.So--there was no real reason to even mess with it.... what a SHAME !!


I did NOT really expect to come back form the ETF with one o0f these..but I am SOOO glad I did !!

Now--if I can get a 4 tube hybrid with the same type cabinet....I have ONE portable of that type already....I would have taken this home just as fast had it been a 4 tuber...

Very, very nice, welcome to the club. I wonder if the safety caps have been swapped out.

I am wondering that myself. I would like to light 'er up....but am a bit fearful of the safety caps....
I believe I need a number of 22-5001 caps, right ?

Yeah, five of them, the orange ones.

Doug Harland recently made a youtube video of him working on one of these sets that was tripping the circuit breaker and the cause was one of the safety capacitors that had shorted.

The guy you bought it from is BigDavesTV, why not drop him a PM to find out when it was last powered up? :)

the finest set ever made.period.congrats!i ve been looking for one too.

I just actually watched Doug's video; so, there are only three of those caps in the 25DC56? In that case I've got a couple of spares, so I can't complain. Also, does an open cap cause the HV to spike, or was at least one of the other two shorted as well?

Nice '60 Chev at the top of his YouTube page. Not a total restyling, but enough of a change to do away with the '59s fugliness. A 4-door too, there's a refreshing change from the usual classic car.

BTW, how's this for the cause of a tripping breaker? Saw it on ARF a few weeks back.

I have a couple new pictures--from the set in the garage now. One shows it ON---I took a chance---all seemed ok. I gave it about 45 seconds or so for the tube to preheat--and then powered it on. The raster came on INSTANTLY, snow and white, (NO analog here in years ). I have a BIT of purity issue in the corner--but not bad--and likely easily remedied.

(the black bar in the oix is NOT really there--it must be some sort of shit with my phone--it is NOT there in person).

You have to admit....Zenith started a NICE, but short-lived trend--with the VRT magnetic regulation. For a few years...most mfg's used them, even in one chassis, RCA, (the ctc-74/81). Zenith even used the VRT in the first gen. of the system 3 chassis---but after that....the dreaded 9-160 module and it ALL went WAY downhill...after that.


I DO realize some here will remind me that actually DUMONT in the early 1950's, maybe late 1940's--used the Sola Voltage Regulating Transformer power supply--so Zenith did NOT use it first, but in a SS tv--they DID. They even used them in a few BW chassis sets, including the 19GB1.

I wouldn't power it up again until the safety caps are replaced though. The video shows that excessive high-voltage doesn't cause damage instantaneously.

Not likely that I will....I just wanted to "see'. I was ready in case I heard ANY sizzle or arcing.....but I did NOT hear any. it was only on long enough to get a picture of it--then I pulled the plug.

Sounds good. I heard an unusually loud crackle in the video once a safety cap lead was clipped and the set powered up.

If your 22-5001 caps are white change them, if orange they are OK.
The HOT in the Zeniths are rugged. In most sets a bad cap would
mean instant death to the HOT. The flat chassii NEVER had sets
destroyed by open caps. There are 5 of them IIRC 2 on the FBT
& 3 under the chassis. Early upright chassii also used 5 caps.
If the set is run long term with an open cap or two the focus divider
& CRT socket go bad. You also get a strong crackle on turn on.
If more go you will see an awesome lightning show around the anode
& divider.
Congats on the set. The CRT looks good as new from what I see & the
set is super clean, wish it were mine.............

BTW IIRC you can get at the dial lamps from the front. Uses either
#159 or #259 bulbs, can interchange.

73 Zeno:smoke:

I only now notieced the channel bulbs were out. I figured they were #44 or 47, not #159. No matter....I have some 159 or 259's in my nightstand drawer for stereo dials IIRC.



Here is a question--likely for the "oldsters" here.

I KNOW and understand how a bad retrace cap(sometimes called tuning cap or safety cap) can and WILL cause a serious increase in HV on a SS set. I think I first read of the situation from radio-electronics, in an article from the late '70's or so by Jack Darr. He explained the whole deal with the tuned ckt, and how if a cap in the collector of the H-out opens--it upsets the tuning--and the HV will the increase--sometimes a LOT !! He spoke of some engineers from Admiral or maybe Zenith, who purposely tested this theory--and said the HV would spike to OVER 40kV, and said that was as high as the meter went !! Of course--this was as a warning to make SURE the tuning caps in certain sets--such as Zenith flattys and the 4-lead caps in the vertical sets too--were good. I learned all of this in the late 1980's or so.....and MUCH , MUCH more from his articles....


HOWEVER....I am curious. Did this happen in TUBE sets? I know that if the shunt reg opened up, the HV could go over 30KV. or so. BUT ..was their any sort of tuning caps off of the plate ckt of the H-out tube, as in the SS sets--that could cause this??

Open capacitors or ones that have changed in value will cause the HV to increase. How much of an increase will depend on how many capacitors have opened or shifted in value. If any capacitors short, it will trip the circuit breaker.

Yo dude.:D
NO. In tube sets, regulator failure would simply let the no-load voltage float up to 30KV or so.
But the SS "safety cap" failures that literally cut the necks off CRTs :yikes:were utterly unheard of until they started happening.
Seems like that unlike a tube, the output transistor is a 'hard switch', capable of driving the "fly-back" spike ((from which the HV is derived) to far higher levels than a tube could possibly manage.

That is just beautiful!!

So the "HOT redplating" I've heard of could be caused by a regulator failure? Better to blow *a* tube than *the* tube.

No. Red plating of the H output tube is from excessive plate current, usually caused by loss of grid drive or a shorted flyback.