TV from the 50s

[Retro-guy]

Got this TV a while back, its a GRUNDIG ZAUBERSPIEGEL 439 from Germany What worries me a bit is that some chassis rust which means moisture and humidity is not good for these TVs primarily for HV transformer (flyback). Capacitors are definitely bad so need replacment.TV looks pretty easy since all of the fifties TVs were, tubes and two resistors and a capacitor.

http://www.radiomuseum.org/r/grundig...iegel_439.html

Now I recently had a bad experience where I powered a set up not knowing it was exposed to humidity a lot and of course the LOPT(HV-winding) melted shortly after that.Now this TV has some surface rust which means damp environment,Now how can I get the moisture out of the LOPT if it has any in it and how to tell if its been damaged by too much humidity ??


The CRT looks good, the gun inside the tube doesn't look discolored but all silver, which is a good sign maybe is a rebuild/replacement , also tested the filament and it is intact, looks very original ...

how to make sure flyback will not destroy itself if it has moisture in it and get that moisture out

[Retro-guy]

more pics

[rca2000]

One way to drive moisture out of deep places....is to heat the part to about 150 degrees F and keep it there--for at least 8 hours or so. This temp should NOT be high enough to hurt or melt anything..and should drive any moisture from any windings--all the way through..

Not sure if you have an oven large enough to hold the set--but maybe the chassis would fit in it.

But--NO HIGHER than this..or you WILL destroy things !!

[Phil Nelson]

I'm not familiar with the construction of flybacks in European TVs, but your chassis does not look severely corroded, overall. I have seen radio and TV chassis with more surface rust than that, and their transformers were not harmed. Outer appearance is not necessarily a good indicator of a component's internal health. A dedicated flyback tester can check the flyback electronically. I don't know of an easy way to judge whether it might have absorbed too much moisture.

If you don't have a huge oven, you could place a flood lamp near that part of the chassis and let it warm things for a long time (say, a couple of days). Better than nothing, and it might help.

I like the appearance of your TV. Vintage European televisions are never seen here (on the West coast of the US), so anything of that nature looks exotic to me.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[EdKozk2]

Notice the flyback has primary winding at 90 degrees to the secondary on the ferrite core, like a torrid. Looks like some of the electrolytic popped their vents too.

[stromberg6]

Love the name: "Zauberspiegel", "Magic Mirror". Hope you get it working, and post some more pics.
Kevin

[dtvmcdonald]

UK-ers worry a lot about damp "LOPT overwinds".

Go to http://www.forum.radios-tv.co.uk/

in the TV forum they have a sticky thread about the subject.

General idea is to apply a couple of watts of DC or 50Hz (its England!)
to the HV part and let it get up to 150F or so for
rather long, like a week.

[Phil Nelson]

Sheesh. I gather there is some difference in construction between those LOPTs and American flybacks. It can't be climate alone -- I live in one of the dampest parts of the USA and I don't need to pull out all of my flybacks and bake them for weeks on end.

Phil Nelson