My Attempt at Predicta Restoration

[PredictaNoob]

If it is OK with the group, I'd like to chronicle my efforts to restore this motel salvage set. I've seen this done here, and quite honestly, the documented steps that others here have bothered to share was the catalyst for my decision to attempt a similar project. This first installment of photos were taken by the guy I bought the set from, so this is how it looked when it arrived at my P.O. Its a 59 Philco Predicta, Debutant model, 10L43 chassis. It was missing the back and power cord, but otherwise complete. It arrived with one small crack to the CRT cover, only visible from the top and won't effect viewing. It smells like hell, if Frank Sinatra were Satan.

[PredictaNoob]

Here is the chassis before I cleaned it. The whole shebang smells like its been sitting in a giant dirty ashtray for the last 40 years. And as a former smoker, I really, really hate that smell...:




And the ill fitting round speaker someone had installed. I've ordered a proper oblong 4 x 6.

[PredictaNoob]

Here is the chassis after I cleaned it with q-tips and alcohol (a technique I learned from here!). I tested the resistors and found 20 of them on the board and tuner that were out of tolerance! I've been attacking the rust, but still have a few places to address while I wait on the replacement parts to arrive.

[DaveWM]

Originally Posted by PredictaNoob

Here is the chassis after I cleaned it with q-tips and alcohol (a technique I learned from here!). I tested the resistors and found 20 of them on the board and tuner that were out of tolerance! I've been attacking the rust, but still have a few places to address while I wait on the replacement parts to arrive.

something about that pot on the extrerm right does not look right, Although the mounting arangement seems correct for the type of pot used. Odd. just a guess but the resistor is prob a higher than called for value and the pot is lower than called for. that way less voltage drop across the pot so a lower wattage pot would work (but the range would suffer as well so the fixed resistor would have to be pretty close to the correct total required value).

[DaveWM]

the lin pot calls for a 1500 ohm with an internal stope at 180 ohms.

[PredictaNoob]

Originally Posted by DaveWM

the lin pot calls for a 1500 ohm with an internal stope at 180 ohms.

Good catch. I hadn't even noticed that oddball until you pointed it out, (and the plastic insulated wire should have been the dead give away).
Its a flippin .5 MEG pot at 2W.
Sheesh, I'll order a proper pot when I order the resistors tonight.
Good news is that the caps arrived today.

[DaveWM]

half meg? geez there must have been a super critical adj. check check the tube resisitance on pin 9 of the 6dr7 vert out tube to ground. Should be around 450 ohms, give the meter a chance to settle in as there is a bypass cap across it. It must be set to nearly fully closed (min resistance).

[wiseguy]

I had to try this method of removing rust from a tuner shield from a kenwood kw-1100u amp..interesting as within 3.5 hrs it has dissolved part of the SS spoon off completely..LOL, i find it entertaining.. and interesting..and the rust spots are almost gone..

[DaveWM]

OP seems to have dropped off the planet.

[bandersen]

Originally Posted by wiseguy

I had to try this method of removing rust from a tuner shield from a kenwood kw-1100u amp..interesting as within 3.5 hrs it has dissolved part of the SS spoon off completely..LOL, i find it entertaining.. and interesting..and the rust spots are almost gone..

That's a real nice power supply you've got there!

Originally Posted by DaveWM

OP seems to have dropped off the planet.

Maybe he never made it back from Normandy ?

[wiseguy]

The Power supply shot is to Show The voltage and current of the "part" in the bowl was drawing and it's setting..(which was 6 volts).. interesting as soon as you lower the rusty metal part into the salt and water mixture it really draws some power during this process..... this why I am glad I don't have a Wife to get upset at me for using silverware from the kitchen drawer for this ...

[PredictaNoob]

Some of the metal parts after rust removal and polishing, but before priming and painting. I used an electrostatic rust removal process to attack the deepest rust spots, using a 6-volt power supply positive terminal connected to a piece of stainless steel, the negative connected to the part (both by-way of cheap alligator clips and some 16 gauge wire. The process pretty much destroys the clips). I used a plastic tub with a solution of salt (1 tbsp per gallon) and let the whole thing soak overnight connected to the power supply. It basically replaces oxidization with ferrous compounds from the stainless steel ~ think Dorian Gray!)

This is pic where I used this process on an old metal/porcelain caster:


Here are the parts:

[Phil Nelson]

Originally Posted by PredictaNoob

I used an electrostatic rust removal process to attack the deepest rust spots, using a 6-volt power supply

I meant to ask this question when you posted the photos, but better late than never.

What did you use as a power supply? I have an old trickle charger that I used to recharge my motorcycle battery each spring. Maybe that would work.

Those pieces looked so good after the electrolytic process was done, I'm wondering why you then went on to paint them. Did they still have pitting where rust used to be?

Phil Nelson

[PredictaNoob]

Originally Posted by Phil Nelson

I meant to ask this question when you posted the photos, but better late than never.

What did you use as a power supply? I have an old trickle charger that I used to recharge my motorcycle battery each spring. Maybe that would work.

Those pieces looked so good after the electrolytic process was done, I'm wondering why you then went on to paint them. Did they still have pitting where rust used to be?

Phil Nelson

That is exactly what I used, a 6-volt trickle charger; hooked the leads to a short length of wire attached to some super-cheap copper alligator clips (since they get destroyed in the process). I went ahead and primed and painted the pieces because I've found that even though the rust is removed/replaced, the 'aged' spots will quickly rust again with a vengeance. There was some pitting, but that was there before the process. Typically, whatever is present stays in place and will be replaced by the ferrous compounds. If the rust has left pits, it will remain pitted.

On an aside, years ago I found an 18th century toy gun outside of a castle in Rhineland-Pfalz. It was a rusted ball, that I thought was an actual gun. I worked on that thing for weeks, electro-bath, dental pick, again and again. After a few days, it was clean enough to recognize as a toy gun. Finally, I was able to free up the firing mechanism. I've been a believer in this process ever since.

[Sandy G]

Wow...I can hardly wait to see more progress...Howzabout the caps ? I'm sure they were a disaster like the resistors were, too...You obviously Know What You're Doing...