Philco Predicta restoration

[josephdaniel]

Hopefully this will be the last thread I start for this set!
I started recapping and replacing resistors last night on the main PCB. I had new 5% tolorence resistors for most of the board so I went ahead and used those. There was only a few resistors that didn't get replaced...

Here is a picture for your enjoyment

[Kamakiri]

Boy, that looks familiar. I just did the same thing a couple months ago. Got my set back together, and, well, let's just say that it needs further diagnosis.....

[josephdaniel]

I'm pretty sure that this set will too, but I figured I might as well do what I can and see where that gets me... I might get lucky and have a working set!

[init4fun]

Originally Posted by Kamakiri

Boy, that looks familiar. I just did the same thing a couple months ago. Got my set back together, and, well, let's just say that it needs further diagnosis.....

What you gents are experiencing with these recapped sets having problems has got me to wondering , , Are you checking the value of each new component before installation ? Back when I was first starting out , I used to take "Brand new" to mean "Perfectly working" and MAN was I let down ! Time and again I'd do a recap and run into the same thing , "Damn ! This set ain't any better than when I started with it !" .... I would invariably end up going back and checking the new components one by each and the failure rate was appalling ! Since then , I test each new part before installation and my restorations have gone much more smoothly . Nothing too involved , just take an ohm meter to the new resistors and a good old capacitor checker* to the new caps , and weed out the factory defects before they end up in the set . Even parts of supposedly "tight tolerance" like those resistors with the pretty gold bands on em aren't immune to the occasional factory derp , so a working check of all replacement parts really is time well spent . Tell me , you DO test each tube you put into a set , even a brand new tube , right ? So why not check all other replacement components as well , especially since we know an ohm meter's reading of a resistor is a far better indicator of it's quality than a "good" reading of a tube in a tube tester is

* "Good old capacitor checker" meaning any unit that tests the new cap at it's actual working voltage , which leaves most if not all new digital style meters sorely lacking . Gotta get one of the kinds with the eye tube and adjustable voltage up to 450V for the "breakdown" test .

Good Luck and happy restoring ...

[bonanzaman]

Originally Posted by josephdaniel

I'm pretty sure that this set will too, but I figured I might as well do what I can and see where that gets me... I might get lucky and have a working set!

Are you doing any of the bloody k-networks while you have access to them? I'll be starting a Princess in a few weeks, and they are all getting rebuilt

[josephdaniel]

I want torebuild the k networks but I'm just gonna see how it works as is. I have been told that allot of predictas that have been restored are still working on their orgional networks. If they do turn out to be bad I will try and build somelikethe ones that banderson made a while back...

[bigaudioal]

Originally Posted by josephdaniel

I want torebuild the k networks but I'm just gonna see how it works as is. I have been told that allot of predictas that have been restored are still working on their orgional networks. If they do turn out to be bad I will try and build somelikethe ones that banderson made a while back...

Seems like those networks are not too bad to rebuild if you take the time and draw everything out from the schematic like Bob did in his videos. Takes time, but did not look that difficult. And if you are not concerned about cosmetic originality, you don't have to epoxy and paint them.