[Nathan Slingerland]

Very impressive with the replating.

I’ve been just dusting with a small brush and vacuum - then spraying with contact cleaner. Works decent but Mike your dishwasher would do a bit better than what I’ve been doing.

[rfeenstra]

I've put many in the dish washer. Works good.

Nathan, do you have a scan of the patent label for the 20?  I couldn't find one in the Library, just the tube layout.

[Nathan Slingerland]

Unfortunately no scan of the model 20 patent label (yet). The 20 I have currently has a patent label but missing too much to make a decent source.

I didn't realize that RadioDaze made them but for what it's worth they do have it: https://www.radiodaze.com/philco-20-mode...lbl-ph-20/

[fenbach]

what do you replate the tuning cap with? and how? is it a DIY process? seems to me you'd want the chassis to look as nice, too. and that would keep you occupied for a while.

[rfeenstra]

It's tin plated, DIY. Not very original but I was playing with it. There was some rust so some of the original plating was gone. I didn't want it to rust again so I tin plated it. Tin is much brighter than what was used originally. the tin will oxidize over time (just look at the typical tube shield). Unfortunately, it is very difficult to do the chassis. The aluminum shields are spun on and all of the sockets would have to come off. It cleaned up pretty good but definitely is a different color than the tuning cap. The rust that was on the chassis was very light and came off without rust pitting. Not sure if these things are cadmium plated or zinc plated. I'll need to put some sort of film on it to keep it from rusting again. I suspect that zinc plating on the cap would have looked much more like the chassis but I don't have zinc plating capability yet.

Nathan, I didn't realize RD had that! Thanks, but I was able to salvage the original. Not perfect but at least original, not that the radio is going to look exactly original, but...

All of the resistors underneath (except WW) are between 50 and 300% over value so I may try making some. There are only 5 and they are all the same physical size so shouldn't be too bad. they are the type with the molded lead ends so a bit more difficult than the type with the wire wrapped around the end. I probably could get by with hiding a parallel resistor underneath.

[Arran]

What I do with chassis rust spots is to treat them with phosphoric acid, which I have in both a cleaning product I found, and in a type of rust remover. In any event it seems to prevent the steel from rusting again, I guess by converting the iron into iron phosphate, they call it pickling I think. The rust remover was called "Removall" but I don't think you can get it anymore, it would turn the steel grey after the rust was removed, unless you polish it afterward.
Regards
Arran

[Phlogiston]

The bluish-grey tone of the original plating makes me think that it was zinc plated. Cadmium is greenish - just stay away from that. Never scrape sand or brush cadmium without the proper PPE.

[morzh]

Rob

Chuck Paci should have some made.

[rfeenstra]

I've emailed Chuck. I'll see what he has. Thanks!

[rfeenstra]

A no from Chuck. I installed the original resistors with a parallel resistor hidden underneath. Someday, if it ever comes, I'll make new ones! I know Steve makes dog bone's but I don't think this style.

[Phlogiston]

This kind?

   

[rfeenstra]

Yes, Russ, only they are quite a bit larger. Do you have aplace on your blog that demonstrates how yo make those?

[Phlogiston]

I have been looking and haven't found any good pictures of the processes.

There are at least two ways I have done this.

Pictured is a resistor that has the original lead (Pb) ends (metal - no paint). These are made by removing the ceramic center (white part) and replacing it with a glass (preferable) or plastic tube. There are Pyrex tubes with the proper outside diameter for most of these, BUT, their inner diameter might limit the size of the replacement (watts). A plastic tube might allow for larger inner diameter but resistance to heat is diminished.

The second, and far easier, way is to mold the whole thing and paint it. I will get a picture of the mold posted when I get over to the shop.

[rfeenstra]

Thanks Russ.

[Phlogiston]

Hi-temp silicone -