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#1
09-26-2016, 04:11 AM
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Predicta Tandem Scored in Akron
I ended up finding a complete Predicta Tandem at a vintage store in Akron, OH for the paltry sum of $100. The CRT is marginal, and It's the blonde cabinet I really don't like, but It was too cheap to pass up.
 (photo taken after I pulled the Chassis, I have all the knobs.) The chassis is dirty, the fusible resistor has corroded in to a pile of green copper and sand dust on the Chassis, and the multi-tap sand resistor in the filament chain is roached as well, along with the thermistor. The wood base that holds the Predicta CRT pedestal is falling apart.  Good News: Plastic CRT housing is in good shape, along with the CAB safety lens, 25ft CRT cable, and CRT connector. CRT was replaced with a 21FDP4 some time in the past and is good enough to be serviceable after using my Sencore Super Mack to successfully weld the open cathode. Flyback and Yoke test good on my ring tester. This set has the optional UHF tuner. This is going to be a fun project.
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This device isn't a spaceship, it's a time machine. It goes backwards, and forwards... it takes us to a place where we ache to go again. Last edited by fsjonsey; 09-26-2016 at 04:18 AM. 
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#2
10-01-2016, 01:23 AM
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It's....ALIVEEEE!!!
 I replaced all the open power resistors on the filament string, replaced the thermistor with a CL90, used a 5.6ohm 10W wirewound and a 2A micro breaker to replace the fusible resistor, replaced all the paper caps, and now I have *video (*sometimes) There is a cold solder joint or a crappy tube socket somewhere on the main video PCB, as the set occasionally loses input signal to the video amp tube and the screen flickers to a blank white raster. The sound is also way out of alignment, but meh, It's a start. Most of the tubes are marginal to weak, and Philco branded. They must be original. The CRT seems to be waking up as the set is played. Some of the electrolytics have been replaced in the past, all PS voltages are normal and the lytics test good on my ESR meter. I'll replace them eventually, once the intermittent video problem is solved.
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This device isn't a spaceship, it's a time machine. It goes backwards, and forwards... it takes us to a place where we ache to go again. Last edited by fsjonsey; 10-01-2016 at 01:58 AM.
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#3
10-01-2016, 02:10 AM
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Zounds, that's the best $100 deal I've seen in a while.
You know, some people would pay extra for a blonde cabinet. They can be tricky to refinish, though. You get bonus points for that Euro radio in the background. Reminds me of my Telefunken Gavotte 9 (and 90% of all other Euro radios of the same vintage  ).Phil Nelson Phil's Old Radios http://antiqueradio.org/index.html
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#4
10-01-2016, 02:51 AM
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Quote:
You have a good eye, That's a Telefunken Gavotte 7!  I grabbed it at a local antique mall two years ago for $30 because it was "dead." The main filter caps were shorted, the weird AEG bridge rectifier can was open, and the fuse was blown. New filters, a fresh bridge rectifier, dropping resistors, and a new fuse was all it took to bring it back. I replaced some paper caps and the Magic Eye too. Also, the intermittent video loss on the Philco is frustrating as all hell. The tube sockets are wonky, but that doesn't seem like the only problem since they are all fully intact. None of them have the common Predicta broken pins, but the sockets are really loose. Is there any way to retension these sockets without destroying them?
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This device isn't a spaceship, it's a time machine. It goes backwards, and forwards... it takes us to a place where we ache to go again. Last edited by fsjonsey; 10-01-2016 at 04:19 AM.
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#6
10-02-2016, 10:59 AM
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A good deal for a classic set. I happen to think these Predicta's in blonde are much more "mid-century" looking than the in dark mahogany. I do agree that they're tricky to touch-up and/or refinish though. I heard these are the easiest of the Predicta models to work on.
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#7
10-02-2016, 08:48 PM
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So, here's where I'm at right now. After playing the set for a couple of hours, The intermittent video suddenly faded away into a blank white raster. I'm guessing something has gone open between the IF board and the Video amp tube, or the socket could be crap. They all seem loose. Turning the tuner has no effect on sound or video. Has anyone here had a similar problem with a predicta?
 Also, as you can see, someone in the past cut a chunk out of the wooden base for reasons that are unclear to me now...
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This device isn't a spaceship, it's a time machine. It goes backwards, and forwards... it takes us to a place where we ache to go again. Last edited by fsjonsey; 10-02-2016 at 08:56 PM.
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#8
10-02-2016, 09:50 PM
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Make sure the tuner 5X8 and 4BC8 are both good.. and also the 3BZ6's, 5AM8, and 6AW8.
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#9
10-03-2016, 07:33 AM
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You probably already know this but the Predicta tube sockets are often suspect. The metal in them becomes brittle and will often separate between the tube contacts and the PC board. You may want to try some wiggling and/or look at those sockets under a bright light.
Some members routinely change the sockets as part of a restoration. Glad you saved this set. Please keep us posted!
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#10
10-03-2016, 01:27 PM
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Quite agree. I don't suspect there's anything very major going on here. Wiggle each tube associated with the if and after that the rf sections and see if your signal pops back in. I had a Tandem last year that lost its signal like yours and I noticed that if I pressed down on the front of the pc board the sugnal snapped back in. Turned out there was a hairline in one of the printed circuit traces on the board. After jumpering that the problem disappeared. So don't be afraid to try an unscientific method to find the trouble!
As for the blonde finish, they do fetch more $$$ at auction. My BarberPole is blonde and although I would prefer walnut I know it is worth a good 35% more. They are not difficult to maintain. Believe it or not, I rubbed Novus #2 lightly over mine and it looks like brand new now!
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#12
10-04-2016, 12:14 PM
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Forgot to ask---when the picture went away, did the audio remain or did that go away too??
George
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#13
02-19-2017, 03:15 AM
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Quote:
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This device isn't a spaceship, it's a time machine. It goes backwards, and forwards... it takes us to a place where we ache to go again.
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#14
02-19-2017, 06:34 AM
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Linear Mode
