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-   -   Predicta Princess restoration (http://www.videokarma.org/showthread.php?t=267514)

bandersen 08-05-2016 10:21 AM

Predicta Princess restoration
 
This is the second or third vintage set I ever picked up and the very first I tried to restore. Luckily, I quickly realized I was in over my head before I did any damage and focused on the cosmetics while I practiced on easier sets like the Motorola VT71.

It was the beige version and rusty. The least appealing of the three colors originally offered IMO (Vermillion, Mahogany and Beige). (Also missing the antenna and metal channel selector knob.
https://c6.staticflickr.com/4/3429/3...9d86594a_z.jpg

https://c1.staticflickr.com/3/2145/2....jpg?zz=1

So I decided to strip it, remove the rust and paint it a more appealing red.
https://c6.staticflickr.com/4/3547/3...e26703c5_z.jpg

https://c3.staticflickr.com/4/3458/3...1a539844_z.jpg

https://c8.staticflickr.com/4/3629/3...48af4349_z.jpg

https://c4.staticflickr.com/4/3579/3...41960d84_z.jpg

https://c4.staticflickr.com/4/3611/3...94567949_z.jpg

https://c5.staticflickr.com/4/3540/3...04417dc0_z.jpg

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Here it is back together with a replacement antenna stuck in it. There it sat for 7 years....
https://c8.staticflickr.com/9/8103/2...beeca950_z.jpg

bandersen 08-05-2016 11:01 AM

Recently, I was contacted about restoring a Predicta Debutante with nearly identical chassis. That inspired me to pull this chassis back out and finally attempt to get it running.

Here they are side-by-side. The Princess chassis is on tap and has a few caps replaced from when I started on it years ago.
https://c1.staticflickr.com/2/1557/2...6fb25684_c.jpg

Now back when I started messing round with it I did replace the electrolytics and a few paper caps and tried powering it up. I only got a few flashes of light on the CRT and no sound.

I used an 8YP4 with adapter and moved the filament lead from the low voltage tap to 6.3 volts.
https://c3.staticflickr.com/4/3311/3...80c6fda1_z.jpg

This gassy tube might explain why I got no reception and a flaky HOT might explain the intermittent high voltage.
https://c1.staticflickr.com/2/1530/2...34d7d1fb_c.jpg

I dug right into it using the Deb. as reference. First out came the main board for a full recap including the couplates.
https://c3.staticflickr.com/8/7323/2...6010fb02_c.jpg

I made those up on little perf boards that were dipped in urethane conformal coating and painted with primer
https://c3.staticflickr.com/8/7234/2...338f79c0_c.jpg

Here's a look at the IF board.
https://c7.staticflickr.com/8/7685/2...42a939df_c.jpg

Looking good inside the HV cage.
https://c4.staticflickr.com/8/7078/2...62278201_c.jpg

Cleaning out the CRT head.
https://c8.staticflickr.com/8/7592/2...ed1e3015_c.jpg

It tests good but if I ever need a replacement I scored one from VDC back when they actually had CRTs in stock. Only $65 as I recall.
https://c4.staticflickr.com/4/3420/3...59a028cf_o.jpg

Ready for a power up test ! Note I replaced the electrloytics I has installed before with higher quality ones and used beefier IN5408 diodes.
https://c3.staticflickr.com/8/7133/2...c0ae1bd9_c.jpg

Eric H 08-05-2016 01:48 PM

This is a great thread, it's good to know the Electrolytics can be mounted right on the board and terminal strips, no stuffing cans, I hate that part most of all..

I have a Debutante with a great CRT and a rusty cabinet, I was planning to repaint it in "Vermillion" also, did you have paint made up or is it from a spray can?

bandersen 08-05-2016 02:00 PM

Thanks. Three caps fit very nicely on the main board using existing pads and holes. I think I only had to drill one small hole. It almost as if they anticipated smaller caps being available in the future. The other five caps are also mounted nicely on the existing terminal strips. I'll take some more photos showing exactly where they are connected.

The paint is off the shelf Rustoleum. I think I still have the can and will check the color when I get home.

bandersen 08-05-2016 02:04 PM

I noticed some production changes between the two chassis. I'm guess the Princess is older as most of the wiring harness is cloth covered while the Debutante uses plastic insulated wire.

Also, some components were left of the Deb main board and some values weringe a bit different. Perhaps they refined the design :scratch2:

Electronic M 08-05-2016 02:07 PM

I shelved my first TV resto for a long time too...Then I gradually had 3 of those sets sitting in my basement...Eventually I got sick of dead sets taking up room, had done most better projects in line, and just went for it. It can be VERY efficient restoring 3 of the same set at once, but it you don't like part of the job you will probably have to repeat it.

bandersen 08-05-2016 08:40 PM

I used Rustolem gloss enamel 7762 "sunrise red".
https://c5.staticflickr.com/8/7736/2...787bb924_z.jpg

bandersen 08-05-2016 08:45 PM

After a little tweaking, the set it's playing great :thmbsp: It was definitely a huge help to work on two the same time :yes:

https://c5.staticflickr.com/9/8165/2...cb16c67b_z.jpg

https://c5.staticflickr.com/9/8072/2...f0c18c0f_z.jpg

https://c7.staticflickr.com/9/8361/2...efe8171a_z.jpg

bandersen 08-05-2016 08:48 PM

Almost forgot to mention that years of searching finally paid off and I scored a proper channel knob. It's a little beat up but I'll take it!
https://c1.staticflickr.com/9/8107/8...8aecf5c1_z.jpg https://c1.staticflickr.com/9/8261/8...dfdc0074_z.jpg

decojoe67 08-05-2016 09:18 PM

Another impressive job Bob. It looks very nice.

Radiotronman 08-05-2016 10:35 PM

Bob that looks awesome. Great choice on the red color. I haven't been able to find a princess near me, definitely more stylish than the debutante.

madlabs 08-06-2016 10:26 AM

Looks great Bob. I am plugging away on my Predicta. I'd like more information on your couplate replacements, such as exactly what caps you are using. Since yours work and I don't know what the heck I'm doing I'd like to do a copy of yours, part for part and layout. I hope to finish under the chassis this weekend and would like to get a parts order coming so I can start digging into the PCB next week.

Love the red.

Jonathan


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