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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sat 08, 2019 2:32 pm 
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Joined: Aug Thu 20, 2015 3:09 pm
Posts: 1174
Location: Albion, CA, USA, 95410
As noted above, the fly you ordered won't work. But the one you have can likely be repaired. I had an issue with mine where it arced over.

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I had to cut away a piece of the phenolic and patch in a new piece.

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Soldering the fine wire is a challenge but doable. You will need some non-acidic silicon (sensor safe) or similar to deal with strain relief so it doesn't get pulled off again.


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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sat 08, 2019 5:09 pm 
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Joined: May Thu 14, 2015 4:15 pm
Posts: 1654
Location: Dallas, TX
indy_kid wrote:

Apparently, the structure (wax, cardboard, etc.) for the wire leading from the 1B3 tube to the flyback was in worse shape than I knew. It detached completely, breaking the magnet wire. I attempted a repair, but it's too fine for me, and sitting hunched over the set while trying to effect the repair was murder on my back (18 years since the last fusion; probably time for another).

I went ahead and ordered the single replacement on eBay, a Thordarson FLY 119, which looked identical in the pix. I couldn't find any info about equivalent flybacks online, but it was this one or nothing. I also ordered some silicone sealant and HV dope. The first thing I'll do with the replacement is fill the cracks with sealant (there are cracks in the replacement; the seller gave no guarantee that it will work), then give the outside several layers of HV dope to stabilize it for further handling.

"Crispy" doesn't begin to describe the state of these flybacks! What were they thinking with just a wax covering? Yeah, I know, they didn't expect folks to be messing around with it; once it place and not to be touched again. Still, simple thermal expansion would cause cracks in the wax, which could lead to arcing and other problems. A more robust covering seems like a no-brainer, especially if you want your stock of unsold parts to survive for years in some warehouse.


The cardboard was glued to the coil with a substance like coil dope (styrene plastic dissolved in acetone). The cardboard has a metal terminal attached to it. The fine coil wire is soldered to this terminal and then the thicker wire that goes to the 1B3 rectifier
cap is soldered to the terminal. After that the wax ( bees and/or carnauba) covering is applied. There were not any plastics available at the time that would have aged any better. In fact part of the problem is the plastic insulation on the wire going to the rectifier has hardened. When new the wax could soften enough to slowly flow and heal any small cracks. That is part of the reason old paper capacitors were covered with wax. The wax loses some ingredients over time and hardens, it is over 50 years old. Ever see a 50 year old car tire? No one expected anyone would use vintage electronics after a couple of decades. Brittle plastic, rubber and similar parts are very common part of working on vintage equipment.
It probably would be best to remove the flyback from the set to repair it. You would have to remove it anyway to switch it with a new one. Document the connections well.

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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sat 08, 2019 7:28 pm 
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Joined: Sep Mon 28, 2009 1:53 am
Posts: 268
Location: Bloomington, IN, 47401
I got lucky! Rechecked the resistances and got 375 Ohms (spec is 350) from pin 4 on the Horz Output terminal board and the lead wire to the 1B3, and 22.4 Ohms (spec is 22) from pin 2 of the terminal board to pin 8 in the flyback socket that leads up to the picture tube! Not going to touch it until I get the silicone and HV dope in to seal it up.

The problem is still no HV. If I'm reading the SAMS schematic correctly, it should be getting 275V (or at least 275V feeds into R69, R70 and C52). Also some voltage via the grid of the Damper (6DA4). Looks like I need to make sure I'm getting 275V after L21 near the power supply. Seems odd that I would not, given that the rest of the board appears fully function: all tubes lit, audio is strong. Looks to me like I wouldn't get any audio at all if 275V wasn't on the primary of T5, driving the speaker.

Do you recommend that I rebuild K1 thru K7? I did see a restoration on the web where each of those was replaced.

Finally, what are suitable replacements for the M1 and M2 diodes?


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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sat 08, 2019 8:06 pm 
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Joined: Aug Thu 20, 2015 3:09 pm
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Location: Albion, CA, USA, 95410
Exactly what makes you say there is no HV? Lack of picture or have you done the HV test described above?

For M1 and M2 I used 1n4007's. Yes, I would replace the couplates. Crist Riggoti had them for sale and banderson has in the past too.


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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sat 08, 2019 8:12 pm 
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Location: Bloomington, IN, 47401
madlabs wrote:
Exactly what makes you say there is no HV? Lack of picture or have you done the HV test described above?


Did the test with a CFL. Nothing. No picture on the picture tube either, even though I can see the glow of the tube filament, and it tested good with a B&K CRT tester.


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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sat 08, 2019 8:59 pm 
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Joined: May Thu 14, 2015 4:15 pm
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Location: Dallas, TX
Some additional info. The CFL lighting up means that the horizontal output and flyback are
carrying the large amplitude horizontal frequency signal. It would not detect that the H.V.
rectifier was bad or there was a break in the flyback secondary. In this case since the bulb
doesn't light the horizontal output circuit is not working. It could be that the horizontal
oscillator isn't running or running very off frequency.
Ah, dampers do not have grids. One of the things dampers are used for is to create a higher
voltage than B+ supply (often called boost). I haven't seen the schematic so I don't know if
that is the case here.

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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sat 08, 2019 9:18 pm 
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Location: Detroit, MI USA
At this point I'd want to put a scope on the G1 of the horizontal output tube to verify that the drive waveform was present and looked reasonably like it's supposed to.

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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sat 08, 2019 9:54 pm 
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Joined: May Thu 14, 2015 4:15 pm
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Location: Dallas, TX
I wouldn't be too surprised that the OP does not have a scope, it would really help though.
Indy_kid you will have to re-cap this set. Unfortunately with Predictas getting to the parts
to replace them is one of the toughest parts of a restore.
Having a CRT as good as yours is a very good thing, they are hard to come by.
Don't you dare part this set out! Sell it un-repaired if you have to. Pick something easier.
If you want to continue then you need to proceed in a orderly fashion.
Check the supply voltages, check the grid and plate voltages (except the horizontal output plate
and damper cathode) of the horizontal section, then the sync circuits.
Here is a restoration article about a Predicta.
https://www.antiqueradio.org/PhilcoH341 ... vision.htm

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It's not the Destination, It's the Journey.


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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sun 09, 2019 12:49 am 
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Location: Bloomington, IN, 47401
Notimetolooz wrote:
I wouldn't be too surprised that the OP does not have a scope, it would really help though.


That's an interesting assumption, and you would be wrong. I have a BK Model 2190A and know how to use it. I haven't up to this point in the rather optimistic hope that the fix might be simpler than it is.

In fact, I have 2 scopes at the moment but am trying to sell one.


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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sun 09, 2019 1:29 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 27791
Location: Detroit, MI USA
Predictas are never, ever, simple to fix unless you get something like a tube failure in a set that was already restored. Other than that, expect the worst. It's a set that you pretty much want to go through from one end to the other the first time you pull the circuit boards out to change the caps, might as well do everything else that's known to cause issues like certain tube sockets and the couplates all at the same time.

Even when they were just a few years old, technicians hated them because they were so difficult to service and many of them were quite unreliable.

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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sun 09, 2019 3:47 pm 
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Joined: Aug Thu 20, 2015 3:09 pm
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Location: Albion, CA, USA, 95410
Mr. Detrola wrote:
Predictas are never, ever, simple to fix unless you get something like a tube failure in a set that was already restored. Other than that, expect the worst. It's a set that you pretty much want to go through from one end to the other the first time you pull the circuit boards out to change the caps, might as well do everything else that's known to cause issues like certain tube sockets and the couplates all at the same time.

Even when they were just a few years old, technicians hated them because they were so difficult to service and many of them were quite unreliable.


Words of wisdom there. I only had to pull the main board on mine twice. The second time was because one of the audio coils had a busted slug. Do EVERYTHING while you have the board off. I had my wife help me go through the board twice to make sure I got everything in correctly and sure enough she found a mistake.


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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Sun 09, 2019 5:26 pm 
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Joined: May Thu 14, 2015 4:15 pm
Posts: 1654
Location: Dallas, TX
indy_kid wrote:
Notimetolooz wrote:
I wouldn't be too surprised that the OP does not have a scope, it would really help though.


That's an interesting assumption, and you would be wrong. I have a BK Model 2190A and know how to use it. I haven't up to this point in the rather optimistic hope that the fix might be simpler than it is.

In fact, I have 2 scopes at the moment but am trying to sell one.


That is good news. I can't count the number of times I've tried to help someone with their first TV when the only
tools they have are a screwdriver and a free DMM they got from Harbor Freight. It makes it challenging to say the least.

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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Mon 10, 2019 1:16 am 
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When I was a new employee at RCA Broadcast Div. in 1972, the guy in the next cubicle was an old-timer who fielded calls from TV stations having problems with older cameras, switchers, etc. One day I heard him on the phone a long time with a customer, and he finally came out shaking his head. He had been trying to talk a guy (allegedly the Chief Engineer of a small station) through the repair and setup of a pretty ancient studio camera and had finally been asking him questions about timing and waveforms. It turned out that the only test equipment he had at the station was a VOM!

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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Mon 10, 2019 1:19 am 
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Location: Bloomington, IN, 47401
Notimetolooz wrote:
Having a CRT as good as yours is a very good thing, they are hard to come by.
Don't you dare part this set out! Sell it un-repaired if you have to.


If someone wants it at $300, I'll throw in the BK CRT Tester and the remaining parts I have on order. Both tubes in the tuner were wrong, so replacements are coming for that.

I don't plan to do anything to it until I have the silicone and HV dope and can stabilize the shell of the flyback. Don't need any more wax breaking off it. So, will be a few days before I post again.


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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Thu 20, 2019 2:03 am 
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Location: Bloomington, IN, 47401
indy_kid wrote:
I don't plan to do anything to it until I have the silicone and HV dope and can stabilize the shell of the flyback. Don't need any more wax breaking off it. So, will be a few days before I post again.


The rest of the parts finally came in (HV dope, 630V cap assortments, proper tubes for the tuner), and I stabilized the flyback with the HV dope and silicone. Flyback winding resistances still good.

What I hadn't planned on was a flare-up of my spinal problems. I have Ankylosing Spondylitis, and low-pressure weather systems are murder on my back. I have fused C5/6 and C6/7 vertebrae with a plate holding all 3, plus fused L4/5 and L5/S1 vertebrae and a plate holding those. Been about 17 years since those surgeries (3 blown disks in 6 months), so the vertebrae adjacent to the fusions have been slowly wearing out. My last pain mgmt doc said that based on x-rays and MRIs, I should expect a thoracic disk or two to go out, and was getting steroid injections there to forestall a rupture. Unfortunately, my pain mgmt doc went and got himself busted for writing illegal scrips (he was banging a 20-something "patient" - in the office with other patients waiting - in exchange for opiods), and I haven't been able to find another in my area. Every doc is scared of the DEA, so getting any opioid scrip is a miracle. The doc managed to avoid a prison sentence (old white guy, AF veteran), but he'll never practice again. IMHO, he should have gone away for 3-5 for all the trouble he caused all his patients. I had to go cold-turkey off oxycodone at the same time I was dealing with the largest kidney stone of my life. That was a bad month.

So, it will be slow-going for awhile, but that's okay. Take my time and do it right.

I did get a 3rd O-scope, a Tektronix TDS 544A digitizing, 4-channel scope, but it has issues of its own. A mid-1990s model, and they all need recapping at this point. Lots of forums about doing that, and it doesn't look that hard, so I have my next project once I get the TV working. Way more scope than I'll ever need!


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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Thu 20, 2019 6:01 pm 
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Joined: May Thu 14, 2015 4:15 pm
Posts: 1654
Location: Dallas, TX
Sorry to hear about your medical problem.
From your username I might of guessed you were younger. Without bio information people just have to
guess. It is kind of impolite to ask.
I have a couple of lumbar vertebra fused myself. Likely things worked out OK so I'm not in a lot of pain.
The reason for my back surgery was entirely different.

I and a couple of people I know from the Dallas area passed through Indy on our way to the ETF Convention
near Columbus back in early May. I know at least one of use would have taken the set off your hands for a
reasonable price. I don't plan on going next year in May, but the others might.

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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Fri 28, 2019 12:30 am 
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Joined: Sep Mon 28, 2009 1:53 am
Posts: 268
Location: Bloomington, IN, 47401
Giving up on the restoration. Depression is hitting me hard lately, and I'm in no shape to work on it.

$225, and the BK Model 440 CRT Tester is included. All the tubes are good. I've replaced a few diodes and caps. Picture tube is good. Flyback winding resistances still read good. I'll even throw in a jar of HV dope!

Local pickup. Shipping would be VERY expensive, not to mention risky to the picture tube.


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 Post subject: Re: 1959 Philco Predicta Restoration Thread
PostPosted: Jun Fri 28, 2019 6:31 pm 
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Joined: May Thu 14, 2015 4:15 pm
Posts: 1654
Location: Dallas, TX
Things like that happen. Hope you find a good doc soon.
Put an ad in the Classifieds Category here with pictures.

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It's not the Destination, It's the Journey.


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