Predicta Holiday restoration

[IsthmusTV]

Bravo!! It looks like all your excellent work replacing the "K" networks really paid off. Congrats!

-Clark

[bandersen]

Originally Posted by cwmoser

Hey Bob, I'm collecting knowledge on these old Predicta's because they seem to catch my eye. Can you post a
picture of a new tube socket and tell who can supply them?
If I find a Predicta, might as well replace all the tube sockets
with the recapping.

Thanks

Carl

They're identical to the originals.

Check out these two earlier posts in this thread.
http://www.videokarma.org/showpost.p...3&postcount=28

http://www.videokarma.org/showpost.p...1&postcount=32


There are also some white ceramic ones available like these guys that might hold up better: http://www.ebay.com/itm/10-ceramic-9...-/320962006659

The central ground post doesn't go through to the PCB though. Not sure if that matters.

Originally Posted by IsthmusTV

Bravo!! It looks like all your excellent work replacing the "K" networks really paid off. Congrats!

-Clark

Thanks! Now I'll be forever curious if these networks are working as well as the originals would have

[marty59]

I've not done anything with the couplates in my Predicta but I sure like how yours turned out. I could imagine my luck could change at some point....

Once you know everything's fine I do like the heatshrink method to protect/cover 'em with.

[mpatoray]

Great work with this set! It has been a great thread to follow. Cant wait to see it all done!

[Mars777]

Congratulations Bob!

The replacement couplates that you designed seem to be a valid replacement after all. Nice work! I am suspecting bad couplates in my Eico 369 Sweep Generator which may be bad/out of tolerance as well. Maybe that is why your Eico 369 is a little out of whack also.

Good luck with the final tweaks in the Predicta!
Take Care,
Tom

[bandersen]

Thanks. I do have vertical jitters so my K networks may need a little tweaking. That or something else is not quite right. I'm in the process of checking all the voltages and waveforms.

[Eric H]

Originally Posted by bandersen

It's tempting to coat these networks in epoxy or silicone, but I'm afraid I may need to tinker with them to get the set running properly.

They do kind of look like they're built out of Saltine Crackers.

[Down Under]

Hi Bob,

I'm reading your post with interest, as I have a Holiday that I'll start working on as time permits. I'm also working on a Debutante and Princess just to punish myself!

With regards to those tube sockets, where does the break occur exactly? It's a bit hard to see, even on your close ups. The boards are out of my 17in TVs at the moment, so I'd like to know what I'm looking for in terms of broken sockets BEFORE I solder the boards back in.

Of course I'll be testing the boards first, but if any of my sockets look suss, I'll replace them.

I'd LOVE to get a Tandem, but I have to be welll cashed up to get one of these. They go for a lot, and then I have to add around $700.00 freight just to get it to Australia!


But thanks for your continued posts, I always find them interesting!

[bandersen]

Checkout this post: http://www.antiqueradios.com/forums/...p?f=3&t=176131

I just happen to have two Tandem sets and will likely sell one off. I'd like to get them both working before I make a decision though.

I'll also be restoring a Princess and Siesta model along with the Tandems.

[bandersen]

I pulled the main PCB again which actually wasn't bad to do now that I've got the hang of it.
Getting the old sockets out isn't quite so easy though. I ended up cracking the old brittle plastic and removing the pins one at a time.

I had thought the replacements were identical to the originals, but I was wrong. The replacements are made from heavier gauge metal and are twice as wide where the old ones broke. They should hold up very well

[bandersen]

Moving on to the cabinet. Structurally it's fine, but the photo finish is badly flaking off around the CRT base.


Perhaps some real veneer is the easiest way to go

[50scraze]

I really need to get on here more! First time I've logged in for months and I see this great restoration. First time I did one of these sets I absolutely hated it, several more later it's not so bad.

I think the wood veneer (teak?) will look really good. Just be prepared to spend a lot of time cutting around all those lines!

[bandersen]

That's real mahogany veneer. I might just veneer that bad center section to avoid having to cut out all the pieces. On the other hand it might stand out if I do that.

[Down Under]

I'll also be restoring a Princess and Siesta model along with the Tandems.

A real glutton for punishment, I love it!

I love the tandems, especially the mahogany ones.

Thanks for that link to ARF, I can see where the sockets fail now. Looks like a job for my magnifier lamp!

[bandersen]

Now that I've experienced the heat put out by the 3-section filament dropping resistor, I've been thinking how it could be eliminated.

I crunched the numbers and came up with about 97 volts consumed by the tubes including a 6.3 VAC replacement picture tube. If I assume 125 VAC at the plug, a 20uF AC capacitor would do the trick.

However, those two taps are there for light bulbs that illuminate the VHF and optional UHF channel knobs. I did a little research and found there are 130 VAC white LEDs available in a BA9S base.
They're a bit harsh compared to the yellowy incandescent blub, but work fine.

I figure I'll give it a try and if I don't like the results it's easily reversible.