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radiotech

Mon Jan 17 2011, 10:27PM

Registered Member #2463 Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546

Turret tuners were the best for serviceabilty, You could
repair them. Switch tuners were a hopeless interacting mess
of tweaks that needed to be in a secret order known only
to tuner-rebuilders, who would exchange your old tuner
for a rebuilt , realigned, unit for about $12,

Happiness is a set of the coils you need to a tuner.

Adam Munich

Wed Jan 19 2011, 01:27AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

So I picked up that old admiral TV today and took it apart...

Nothing too special there, the TV didn't even turn on. However, I hit paydirt with the radio...

It's AM/FM stereo with AFC. All tubes. Aside from a little dust on top the thing is perfect. The filter cap doesn't even need replacing, (though I may do that anyway). The pots don't cackle and the phono that goes with it is perfect. The FM reception is amazing; it gets a perfect signal with no antenna!
I think I might build a wooden case for it.

The front plastic is flawless too. I love craigslist.

1n5ane

Wed Jan 19 2011, 03:52AM

Registered Member #3283 Joined: Wed Oct 06 2010, 11:03PM
Location: Toronto, Canada
Posts: 29

Just my opinion but don't dismantle or destroy "antiques" that could be an easy fix. Perhaps I'm a bit sentimental or something but I really do regret dismantling/destroying some of the things I did.

When I was younger(and dumber); I tore apart a 1930s bakelite radio, one of those wooden "cathedral" style radios, an old candlestick phone and a western electric "lucy" phone all in the quest to expand my parts bin. Most of them were in immaculate shape and could easily sell for much more today...

I don't mean to come across as being preachy but it is sort of sad to see antiques being destroyed for their parts... With age comes appreciation I suppose...

Adam Munich

Wed Jan 19 2011, 04:05AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

Nah, the philco I'm going to try to fix. I think it just needs new caps. Make 4 nee knobs on a lathe and retr0brite the plastic and it's good as new. That's a summer job though.

The admiral had a beat up cabinet and I couldn't even get a dot on the crt. Plus I have no room for it and needed an AC flyback for my x-ray machine. I hate to destroy antiques myself, but some things are just not worth fixing.

I am saving the radio though, and I'm going to breathe new life into it with a wooden case. Once again a summer job...

Edit: I just remembered I have very little woodworking skill... argh.

Edit 2: I just tested the speakers' impedance, 3 ohms. It's a 4 ohm amp! This radio is amazing.

Adam Munich

Thu Jan 20 2011, 03:45AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

The last one I had to pick up. It's an old olympic TV, and by old I mean old.

The thing doesn't even have a flicker of life in it, so I'm just going to harvest the tubes and the FBT.

Arcstarter

Thu Jan 20 2011, 04:05AM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

Grenadier wrote ...

The last one I had to pick up. It's an old olympic TV, and by old I mean old.

The thing doesn't even have a flicker of life in it, so I'm just going to harvest the tubes and the FBT.

What a beautiful bunch of TV sets. I just wish i knew where to find some. I guess it is possible for me to find them on craigslist, but my mom is too eh to drive me anywhere

Adam Munich

Thu Jan 20 2011, 04:58AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

I found them all on CL, pretty much took every old one on there. In 2 months more should pop up.

Here's an arc from the asphalt covered admiral FBT. It doesn't take long for the core to get warm. Also the pic of the olympic one; it's a little smaller so I think I'll use this one for my x-ray, provided I can find a way to clamp the core without the PCB.

So, what sparked the change from pancakes to coils that cover the whole core? (like in modern FBTs)

Ash Small

Thu Jan 20 2011, 06:39AM

Registered Member #3414 Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245

Grenadier wrote ...

.So, what sparked the change from pancakes to coils that cover the whole core? (like in modern FBTs)

I think it was mainly when they started putting the diodes in. I think they tend to have three diodes, with, effectively, three separate windings in series. Modern ones also take up less space.

radiotech

Fri Jan 21 2011, 04:33AM

Registered Member #2463 Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546

Looks like someone already harvested the power transformer
from the Olympic. Its the only one of the three with an ion trap.
Did you pull the power transformer out? Of the 3, it by far the
oldest, and may easily be over 50 years old. Do some asking
on ARF before you take it apart.

These days an old tube *with* a socket with it is desired.

Adam Munich

Fri Jan 21 2011, 06:47AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

That explains why it doesn't power up doesn't it? No I didn't take it out, it was like that hen I got it. Besides I already dismantled it.

Tubes with the sockets you say? Ok, I'll take them out too. Most of the tubes are GE ones so they must be good...

I modified the flyback today. The shellac as falling off so I scratched it all off, and adventure in itself. I accidentally cut the wire with my nail so I had to remove about 20 tuns, not a big deal I suppose. I then took it out of the PCB and dipped it in paraffin to insulate it. It certainly doesn't protect from arcs but it stops corona. I still wouldn't trust it with more than 10kV rms.
For some reason the primary arced to the core. Some waxed paper fixed that.

I've been playing with these things for the past 3 hours. I've gotta say I like these. I like how they ionize the air, like a micro tesla coil. The cores get warm pretty fast though.

Undecided if I'm using the black one or this one in the x-ray. The black one looks more reliable but this one is smaller. Hm...

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