[GarySP]

Hello everyone. For about 2 years now I have been following the phorum under the name "guest". I am very impressed with this phorum and the wealth of info and willingness to help others with vintage radios. I'm just getting started on a Model 20a. I wish I could say it is "farm fresh", but it is more like "ridden hard and put down wet!" Sadly, when I found it it was hanging on a garage wall with coathangers punched through the cabinet. I'll have no problem restoring the cabinet, but electronics restoration is another story. I know just enough to be dangerous!! I'm starting off by fabricating new dogbone resistors, and I have a couple of questions. The set has 50k, 100k, 250k, and 500k resistors in it. I was only able to get the 100k as an exact replacement. Will 51k, 240k, and 510k resistors get me close enough? I'm thinking the originals were probably +/- 20%. Also, the originals were I believe 1 watt. Will substituting with 2 watt be any issue? Any and all help is greatly appreciated. I'll apologize now in advance...there will be times where you will have to explain things to me like i'm 5 years old! Please be patient with me and keep me from electrocuting myself! Incidently, the radio itself was my grandparents. About 35 years ago I plugged it in briefly, and it played, but not very well. Has not been out of the packing I put it in since. I'll try to post some photos later. Thanks again.

[TA Forbes]

2 Watt will be fine.

Pull up the justradios.com site. There are many resistors there that are what you are looking for.

The values you listed are ok. You want to stay within 20%. Personally, I limit that to 10%

[GarySP]

Thanks for the information to the website, Mr. Forbes. I've read enough of your posts to know that you've probably forgotten more about this old girl than I'll ever know!! Seems my initial assessment of this radio may have been a little critical. Other than the holes in the cabinet and one small piece of grillwork missing, it's not in bad shape for 80 years old. (I should be so lucky at that age!) No major problems jump out at me with the chassis. I did notice that it had a dial lamp, but no bulb, and is not on the schematic. Any idea what bulb it should have? It is also missing the tube shield for the 24's. If anyone has one laying around, I'd like to hear from you! The speaker is intact, but had some repairs made to the cone. I'll think about re-coning it down the road. I also noticed the resistors in the set don't have the color coding I expected to see. Just grey tubes with what looks like zinc castings on each end. I'm going to replace them and then start on the caps. Plenty of bakelites in there to rebuild, and the infamous tar can! Thank again. Gary.

[Ron Ramirez]

Hi Gary

Do you mean a dial lamp socket? Early Model 20 sets have no pilot lamp or socket, this feature was added later in production.

The lamp you need is #41, 2.5 volts, 500 mA.

Philco did not start using the standard RMA body-tip-dot color code until 1931 or 32, don't remember exactly right now and would have to look it up to be certain.

[GarySP]

Thanks for the bulb info Ron. I'll pick that up when I go to get my caps. I'm lucky enough to still have an electronics parts store just a couple of miles away from my house. They are truly going by the wayside. The owner says he might even have some NOS tubes I might need...he just has to dig through his very dusty inventory. Says he has two Hickok tube testers, but isn't really ready to part with them. I'll keep trying. On another note, I have an issue with a warped dial indicator. Any clues as to how I might be able to straighten it? It is in very good shape other than the warp. Thanks again for all the help. Gary

[TA Forbes]

Radio Daze and oldradioparts.net both have repop dials should you decide to go that way.

Most of the old dials have a degree of warp-age, if it does not interfere with the travel of the tuning control then I would just leave it.

Good probability that several of your resistors are way out of tolerance. It is important to be sure what resistor it is you are measuring, since you cannot go by the color code.

There are several threads in the phorum that address re-stuffing both bakelite blocks and the filter can.

[GarySP]

Thanks again TA Forbes for the info. I just finished building my dogbones...just need to paint the color codes on them now. I'm replacing ALL resistors and caps in this radio. I'm a walking testemonial to Murphy's Law! Sometimes I think he lives in my back pocket! I can almost gaurantee that if I leave one original component in this set, sure as God made little green apples it will be the one out of tolerance! Will probably start on the caps later this week. I'm really learning on the fly, so one little step at a time. Take care. Gary

[GarySP]

What a racket!!! Cost me twice as much for the paint to color-code my resistors than it did for the resistors themselves!! In reading the other threads lately it looks like this is "rebuild a model 20" month. That great...I can learn from others situations as well. Take care all. Gary

[GarySP]

Hello everyone. Slow but sure progress is being made on my Model 20. I finished making all my dogbones...twice!!! I wasn't happy with the quality of the final product the first time, so I rebuilt them all again. I like to think I'm a meticulous artisan...my wife and kids would just say I'm a--l! Ordered all of the caps and started making detailed drawings before I pull any bakelites out. Like I said earlier, I'm a bare-bones rookie at this. I do have a question though.. while most of the bypass caps are in bakelite cases, two are in what look like metal matchboxes. Was there a reason for this? I wasn't under the impression that caps had to be shielded. I couldn't find a tutorial on rebuilding these caps. Can you point me in the right direction, please? I ordered NTE mylar caps 630v for all the replacements. Are these OK? I've made a couple of observations on the chassis itself. It seems to have a previous repair at the power transformer. A black rubber wire comes from a small hole drilled in the fiber terminal board of the transformer and is soldered to the number 2 lug on the BC resistor. The BC resistor must have been running hot. It melted the pitch in the filter can down into the chassis underside, and glued the can in place rather securely. Would not budge when I took out the screws to inspect it. (Reference earlier thread regarding Murphy's Law!) By the way Ron, are your ears burning? I've always prided myself as being barely above rotory phone friendly. If I ever want to post some pictures in this thread I'll have to get a lot more computer savvy. Photo 101 and probably alot of colorful metaphors here in come! And here I thought computers would just be a passing fad like televisions! As always, thanks for the help and take care. Gary

[TA Forbes]

Hello, Gary: without looking at a schematic I assume you mean the ones in metal cans with 1, 2, or 3 wires coming out one end?

They are easy. Open them up, pull out the innards, re-stuff.

[Joe]

Word of advice when you recap the big tar can that contains the filter caps. You DO NOT have to unsolder all the wires going to the lugs underneath the can! Just take out the four screws holding the can in place, hold the bottom securly and rock the can till it comes loose. Lift it and cut the wires that are protruding from the inside of the can and lift the can off. The base of the can will remain and you can clean that out. Then you don't have to remove all the tar and old caps, just gouge out enough (maybe 2 inches deep), so the new caps fit. Make sure none of the old gunk is loose so it doesn't fall on top of your new caps. I just did this, and everything went fine.

[GarySP]

Hello everyone. Just got the filter can on my 20 out. I tried your advice Joe, but ended up unsoldering the entire unit to get it out. The BC resistor was running hot enough to melt the pitch inside the can, and it cemented the two pieces together. Once I had it out I was able to apply heat to the base and pry it apart enough to cut the wires inside and separate the two pieces. I then propped the filter can on top of a coffee can with some scrap steel and placed the whole thing in front of my torpedo heater in my garage. In less than a minute the innards were sliding out of the can into the coffee can. No muss, no fuss, and no smells in the house to light my wife's fuse! I'm progressing rather slow on this project. I only get a little time here and there to work on it, and I'm not in any marathon to complete it, at least until it's warm enough outside to start on the cabinet!! This is a great remedy for cabin fever. I appreciate all the advice I've been getting. My caps should be here any time now, so for now just cleaning up the chassis. Take care. Gary