[streetmechanic]

Several questions about this little radio-phonograph. (1) There seems to be a general consensus that candohms can't be trusted; what wattage rating do you use when replacing them? I'm guessing they had a heat-sink advantage (rivetted to the chassis) that replacements won't have. (2) Is the 15 ohm resistor (number 70 on the pictorial diagram) one of those "flexible" units that turn up sometimes in 1930's electronics? It's hidden in a piece of spaghetti on my set. Can they be trusted long-term? It tests dead-on accurate now. (3) What do experienced restorers do about rubber-covered wire? My temptation is to leave alone wires that are not actually bare and posing an immediate short hazard, at least until I can be sure the radio will work properly. After that I may consider "doing it right" and rewiring the whole thing- which I guess brings up a fourth question: is there a good source for replacement wire in appropriate colors?
-Dave

[klondike98]

If the candohm is measuring OK I leave them alone as I would with the 15 ohm resistor. The rubber coated wires will likely crumble as you work to replace the paper capacitors. Some colors are less brittle than others but I find I'm often replacing or covering most of them. If I haven't disturbed a wire and it looks intact and it still has some pliability in the rubber I may leave it alone. Other folks may have other opinions I'm sure...

[Radioroslyn]

#1 It needs to drop 125v down to 63v at 150ma which =s about 10 watts of dissipation. At 10wts it's going to get hotter than the hinges of H**l. So you'd want to double the wattage. Or you can use a diode to drop the 125v to 85v then you only need to drop 23v. That =s 150 ohms at 3 1/2 wts dissipation. 5wts is good. You can get power resistors w/an al cast heat sink.

#2 The "shoe string" resistors are wire wound jobs. Haven't seen many bad ones at all. Do not bend them as it can break the resistance wire inside. Left alone they're fine. Can be replaced w/carbon type if needed. Unless it's in a high frequency rf circuit where it's used as an inductor also.

#3 Generally I stay away from '39-'42 Philcos. Those are the rw years. The large chassis are a bit easier more room to work with. Not so much with the ac/dc sets. Try to assess the condition of each wire and replace as needed. Just as good practice I've replaced all of the hv wiring. Have used plastic coated wire. Cloth covered is too expensive and now days it's getting hard to find. About 15yrs Beldon was still selling rubber wire. But minimum order was 500' pr spool @ something like $1 a foot that's one color. Not really hobbyist friendly pricing.
  
I do have a 41-300 which is a great player! Did burn up some rubber wire when servicing it.

[MrFixr55]

Look up Remington wire on eBay. The wire that you want has a UL1015 rating. I use 18 gauge which is overkill for a lot of it, but for the grid and plate you can certainly use 20 or 22 gauge wire. For most under chassis, I don't get too fancy trying to match the original wire, but if you are working on a high value radio, that is a consideration.

Search the forum for "rubber insulation" there are some relatively recent posts of disconnecting one end of the wire and slipping spaghetti or heat shrink tubing over the wire after knocking off the disintegrating rubber insulation. this willl save some time.

[Ron Ramirez]

You can buy from Remington direct, bypassing eBay:

https://www.remingtonindustries.com/

Be aware they do not carry 20 gauge solid wire with UL1015 (600 volt rated) insulation, only stranded. Solid wire is what Philco used originally. In fact I have not been able to find any supplier for good 600 volt rated 20 gauge solid wire. Solid wire is easier to work with when you are replacing multiple wires under the chassis and will stay in place better (far less likely to want to curl up as stranded wire does). Plus, 600 volt rated 20 gauge solid wire more closely resembles the original rubber-covered wire.

Antique Electronic Supply carries 22 gauge, 600 volt rated solid wire. 22 gauge will work for the 1939-42 Philcos.

I used to unsolder one end of a rubber-covered wire, remove the crumbling insulation, then slip heat shrink tubing over one end, heat the tubing to shrink it, and reconnect. However, over the years, I found that it was just as easy to replace the wires rather than resleeve.

[streetmechanic]

I understand that nobody would call this a high-value radio but for me it's got at least two things going for it. I want a good, small-footprint beam-of-light player in my phonograph collection (I'm a nut for 78's) and the cabinet finish on this is original and at least 99% perfect. Taking that into consideration, this is likely a keeper. Years ago I actually owned a 42-1015 in the same shape cosmetically but missing its (notorious) 1942 Philco record changer so I guess I've had the alpha and omega of Philco record players.
The candohm is off-value- I'm guessing the terminals are just crimp connections to nichrome wire which are getting wifty after lots of heat-cool cycles. Not something likely to improve with age.
This is the first (or anyway one of the few) times I've worked on a transformerless series-string radio. Trying to shoehorn new parts in a little cramped chassis while avoiding further damage to rubber insulation calls for new skills!

[Chas]

Hardened rubber insulation can be moved about for service if it is heated with a hot air gun. The rubber will harden once it is cooled into a new position. That meas working around hot wire but generally we poke the pliers or soldering iron in for rework... In most cases the insulation will remain intact, if not there is always replacement with PVC or some suggestions of silicon covered wire (looks a lot like old rubber)...

The heat method is very useful with transformer leads as they are often very difficult to recover with heat shrink.