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Predicta Debutante Restoration
I got this TV last fall and now that other people's projects are nearly all done, I'm starting on my own project. I messed with this TV just a little in February. Then the other people's projects for the nearly the last 5 months.
On with the show! Here is the TV as I got it. The 17" CRT tested very good! https://tvrestorerguy.com/wp-content.../100_7588a.jpg https://tvrestorerguy.com/wp-content.../100_7591a.jpg The chassis number is a 11L43. https://tvrestorerguy.com/wp-content...00_7614a-1.jpg Here is what the chassis looked like after I pulled it from the cabinet: https://tvrestorerguy.com/wp-content...3787746319.jpg And a few pictures after going to the car wash. https://tvrestorerguy.com/wp-content...3787821792.jpg https://tvrestorerguy.com/wp-content.../100_9766a.jpg |
I decided to make up all new networks like I did on my Seventeener II project.
I used my CAD program DeltaCad. I used the Seventeener II drawings a "seed" to come up with the ones I needed for this project. I etched my boards, then populated them. Then they were coated with 15 minute epoxy on both sides. Once cured, they were spray painted to approximate the original colors. https://tvrestorerguy.com/wp-content.../100_1159a.jpg |
I decided not to re-stuff the electrolytic caps. Instead I used the method that Bob Andersen describes in his videos on his restoration of a Princess/Debutante. I still have to pull the main board, and when I do, I'll place the 3 electrolytic's from the small E-Cap.
First up were the 2 200uf 160V caps. I used some 220uf 250V 105 degrees Nichicon caps. They were placed on the terminal strip that is next to the Fusistor. One was a direct replacement on the terminal strip while the other came "from" the large 4 section E-Cap. While I was messing around with the terminal strip I replaced the 2 original diodes with 2 1N5408 diodes. https://tvrestorerguy.com/wp-content.../100_1151a.jpg https://tvrestorerguy.com/wp-content.../100_1152a.jpg The other 3 that came "from" the large E-Cap was attached to the terminal strip located between the main board and the IF board. https://tvrestorerguy.com/wp-content.../100_1153a.jpg https://tvrestorerguy.com/wp-content.../100_1154a.jpg I then removed several wires that were not needed and the "jumpered" the wires where they would have connected to each E-Cap terminal. https://tvrestorerguy.com/wp-content.../100_1156a.jpg |
Nice work so far. You have the motel version ID'd by the white cabinet, antenna delete, and instruction sticker. I have the regular brownish-grey consumer version. That model has always been my favorite Predicta because it's the last model offered in '59, and the cleanest design of them all. I love the expanse of glitter-woven cloth on the front too. Very "mid-century" looking.
Good luck with the resto! |
Top notch work on those PEC networks! :thmbsp:
How did you clean the chassis/PC boards? |
he took it to the car wash. :D
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Awesome work! I never knew there was a 1961 Predicta and that chassis is nearly identical to a Philco 23" console I have. That "cool chassis" design sure beat the hell out of the earlier "warm chassis" Predictas
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Wasn't the Continental (AKA danish modern) model introduced in 1960 ? It used essentially the same chassis as the 17" models but with a better 21" CRT than the original 1958 models.
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I then did the IF board. It was simple to remove. After a good cleaning, all the resistors were replaced with 1W. I then added solder to each ground stud to beef them up. I also checked each coil. All was good.
After the board was installed, I wrapped each wire around its stud 1 or 2 turns. Then cut off the excess wire leaving a small 3/32 end sticking out. This is to aid in removing the wire in the future. Then each one was soldered. https://tvrestorerguy.com/wp-content.../100_1149a.jpg https://tvrestorerguy.com/wp-content.../100_1147a.jpg https://tvrestorerguy.com/wp-content.../100_1150a.jpg |
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Today I worked on getting the main board removed. I labeled each wire with the "L" designation and then unwound the wire wrap. Then unsoldered the ground links. Once removed I cleaned up the excess solder on the ground studs and cleaned off the board real good.
On to recapping. https://tvrestorerguy.com/wp-content.../100_1204a.jpg |
The car wash approach scares me a bit. How do you ensure that no moisture remains in IF coils etc. Having said that it certainly does the job. I'll be watching your progress with great interest.
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The car wash gets the initial cleaning done. For the "final" cleaning as to what you see here, this is what I do. After the board was removed from the chassis, a good look see inspection was done to determine the condition of the board. Both boards were in great shape. Then I head over to the sink and turn on lukewarm water. Then I spray the board with "Scrubbing Bubbles" bathroom cleaner. I let it foam for a few seconds, then I use a 1" chip brush I get from Harbor Freight, to gently, but completely, brush the entire board. Getting in between the components. You'll be amazed at how brown the foam will get. Probably from smoking all those years. Then it is completely rinsed off and the process is repeated. Once rinsed off, I shoot contact cleaner into the pots, tube sockets, adjustable coils, and elsewhere I think it needs it. Then into the oven again for about an hour or out in the Texas hot sun. |
The first thing I did was to add the 3 E-Caps to the board. A big thanks to Bob Andersen for this method.
For the 100uf 50V cap I'm using a 100uf 160V cap. There are 2 area that are already "cleared off" and tinned for the cap! All you have to do is drill 2 holes. I used a 1/32 PCB drill bit. The holes are drilled in the pad just south of the "Vert Lin" screening. Here is a picture of where I drilled: https://tvrestorerguy.com/wp-content.../100_1213a.jpg https://tvrestorerguy.com/wp-content.../100_1216a.jpg For the 10uf 450V cap I used a 10uf 450V cap. There is a small square where the "+" lead will go and you have to drill a hole next to the square for the "-" lead. Again, I used a 1/32 drill bit. On the next one I do, I'll drill the hole a little be further away from the ground link. Once the ground "-" hole is drilled, I scrapped off the solder mask and cleaned an area around the hole of the copper trace so I could solder. This is the only time you need to do this. The last cap goes into existing holes. More on that next. https://tvrestorerguy.com/wp-content.../100_1214a.jpg https://tvrestorerguy.com/wp-content.../100_1215a.jpg For the last cap a 20uf 350V cap I used a 22uf 450V cap. This cap will be placed into the lower 2 boxes labeled "WR1". See the above picture for their location. The left hand hole is ground so the "-" lead goes there. The "+" lead goes in the right hand hole. This hole is connected to the box just north of it. I then took a white/green wire I previously removed when I removed the old E-Cap and wrapped it around the stud labeled "Audio B+", then soldered it into the that last box. Thus connecting the "+" lead to the stud. As a matter of fact, when I was removing the wires from the old E-Cap, if I just left the white/green wire on that stud and cut it about a couple of inches long, I could have used it to jumper to the last "+" box. https://tvrestorerguy.com/wp-content.../100_1219a.jpg An overall picture of the 3 E-Caps installed on the main board. https://tvrestorerguy.com/wp-content.../100_1221a.jpg |
I recapped and changed out all the resistors too on the main board today. I left the high wattage wire wound resistors because the checked good and also looked good too.
I used 1W resistors to replace the 1/2W, 2W resistors to replace the 1W resistors, and 3W to replace 2W resistors. I used a 1.6KV .0015uf Panasonic cap located in the upper right hand corner of the board. I cut some standoffs from 1/2 dowel and used some #2 sheet metal screws to hold them to the board. Time well spent. I'll keep them in my jigs and fixtures drawer for later use. All pretty routine with no problems. I re-flowed the solder joints on each tube socket and gave the board a very close inspection. Before I did the recapping, I ohmed out each coil. All was good. I didn't bother with any of the ceramic disc capacitors either. I did check each slug on the transformers and coils to be sure they could be turned. https://tvrestorerguy.com/wp-content.../100_1229a.jpg https://tvrestorerguy.com/wp-content.../100_1230a.jpg |
One thing to be wary of is that the tube sockets on these tend to go open internally on random pins, and this gets worse the more times tubes go in and out.
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The main board is back into the chassis. Whew!
The tube sockets look like the better ones with the wider metal strip between the the terminal and pin socket. All checked good. https://tvrestorerguy.com/wp-content.../100_1232a.jpg |
A member on the other Forum asked if I checked the resistors that I replaced to see if they were out-of-tolerance.
On every restoration, I replace all the resistors 99% of the time. I log each resistor that was removed and each one that goes in. Just as a matter of record so to speak. On this restoration with the IF and Main boards done, here is the tally. IF Board: 14 resistors replaced. 6 were out-of-tolerance 43% 2 were close to being out-of-tolerance 14% 6 were within tolerance 43% Main Board: 45 resistors were replaced. 31 were out-of-tolerance 69% 6 were close to being out-of-tolerance 13% 8 were within tolerance 18% |
Now that the main board is done I moved on to the HV cage. I cleaned it, replaced the 2 resistors (1 was out-of-tolerance, the other was ok), ohmed out the flyback (all checked good), and sealed the flyback with black Super Corona Dope.
https://tvrestorerguy.com/wp-content.../100_1236a.jpg https://tvrestorerguy.com/wp-content.../100_1233a.jpg https://tvrestorerguy.com/wp-content.../100_1243a.jpg https://tvrestorerguy.com/wp-content.../100_1244a.jpg |
I then moved on to the input power plug. I replaced the 470K out-of-tolerance resistor, replaced the film cap with a .022uf X2 safety cap, and added a fuse holder.
Then I cleaned and lubed all the pots and cleaned the tube sockets. This pretty much wraps up the chassis work. https://tvrestorerguy.com/wp-content.../100_1246a.jpg https://tvrestorerguy.com/wp-content.../100_1247a.jpg |
Watching your work is inspiring. Can't wait to see it fired up.
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Beautiful job, Crist! Would you ever consider making/selling those couplates for those of us who don't have a chance in hell of doing something that intricate and involved?
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Even just the boards and BOM would be great or boards and components.
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I might be interested in a set. I left the original couplates in mine and the vert sync is rather weak. Barely locks in and won't hold for more than a few seconds at a time...If I decide to press it into service I'm going to have to address that.
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Definitely interested in a set (actually 3!)
Thanks! Rob |
OK guys. Give me a few days to get it all together and then I'll let everyone know.
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I plugged in all the tubes and everything else. After a few adjustments on the back of the chassis Bingo!
Still more to do but the picture is very encouraging. https://tvrestorerguy.com/wp-content.../100_1272a.jpg |
Well, my Fusistor is open. I'm thinking of getting a chassis mount resistor and mounting on the back of the HV with leads long enough to reach the plug in sockets. I'll use the original open fusistor connector.
If I use the 5.6 ohms I get 288V for the 275V B+ line. If I go to 12 ohms I get 273V. Of course the 12 ohm resistor runs hotter. Remember I fused the power in. Does this secondary need to be fused? |
After all that work I would fuse the secondary. :yes:
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I did the tuner today. I replaced the 1 paper cap and 10 resistors. 1 resistor I couldn't get to. Oh well. The 1/2W resistors were replaced with 1W and the 1W was replaced with a 2W. I then cleaned the tube sockets and used De-Oxit on the wafer switches. The tally is:
10 resistors replaced 5 out-of-tolerance 2 very close to being out-of-tolerance 3 were within tolerance. I then tried the tv again. I got a clearer picture. https://tvrestorerguy.com/wp-content.../100_1274a.jpg https://tvrestorerguy.com/wp-content.../100_1279a.jpg https://tvrestorerguy.com/wp-content.../100_1275a.jpg https://tvrestorerguy.com/wp-content.../100_1280a.jpg |
Crist, It looks like you are using metal film resistors. What voltage rating did you use for your 1W and 2W resisistors? I'm especially interested in the ones under the HV rectifier tube socket? Thanks, in advance.
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Today I added the new "Fusistor" and a 2A fast blow fuse. I had a 10 ohm 50W chassis mount resistor so I mounted it on the back of the HV cage. I then wired it to the original Fusistor connector. The 10 ohm value will give me a B+ voltage of 280V using my wall outlet which gives 123VAC. The normal B+ voltage is listed as 275V. This way when the HV cage needs to be removed they can be unplugged without any fuss.
I also installed the IF board cover. https://tvrestorerguy.com/wp-content.../100_1305a.jpg |
I then turned my attention to the CRT/Yoke. I removed the CRT from the shell and gave the CRT a quick wipe down.
I replaced the 2 680 ohm resistors (both were within tolerance) and the 120pf 5KV capacitor. I used a 120pf 6KV cap for that. https://tvrestorerguy.com/wp-content.../100_1286a.jpg https://tvrestorerguy.com/wp-content.../100_1289a.jpg https://tvrestorerguy.com/wp-content.../100_1292a.jpg https://tvrestorerguy.com/wp-content...4467328272.jpg https://tvrestorerguy.com/wp-content.../100_1293a.jpg I then cleaned up all the wiring and cleaned the connectors too. I then used my lacing cord to tie up each bundle neatly instead of the tape Philco used. https://tvrestorerguy.com/wp-content.../100_1295a.jpg I then cleaned up the inside of the shell. It had a lot of "soot" in there. Now nice and clean. https://tvrestorerguy.com/wp-content.../100_1300a.jpg https://tvrestorerguy.com/wp-content.../100_1304a.jpg |
I noticed that the wire going to the Plate Cap from the 6DQ6 Horizontal Output tube was missing some insulation where it enters the cap. I looked closer and noticed that the inside was was corroded green and needed attention.
I replaced the wire with some 20KV wire that I have. I also used a silicone grommet where the wire exits the HV cage. Dan Jones gave me this tip at his presentation at this years ETF Convention. All better now. https://tvrestorerguy.com/wp-content.../100_1315a.jpg https://tvrestorerguy.com/wp-content.../100_1318a.jpg https://tvrestorerguy.com/wp-content.../100_1321a.jpg https://tvrestorerguy.com/wp-content.../100_1323a.jpg |
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