Mystery 1930s Philco name that Resistor ??
 

I'm in the middle of recapping a Philco U-1 anyone heard of it coz Google hasn't . Anyway I have a popped resistor can anyone give me a definite value see pic

Re: Mystery 1930s Philco name that Resistor ??
 

Could be 47 or 470 Ohms .

Re: Mystery 1930s Philco name that Resistor ??
 

The two remaining chunks tested at 2.2k and 1.2k respectively apparently some sort of 1930s coding I'm not used to

Re: Mystery 1930s Philco name that Resistor ??
 

Coding is (or was) body, tip, spot or ring. Looks like the tip code has been fried.

So value begins with 4, ends with ring as number of 0s. Ring looks brown but could be faded black or even cooked red or orange. Location in the circuit should give the game away......

Just looked at your profile to try to reconcile your avatar pic with your username!

Re: Mystery 1930s Philco name that Resistor ??
 

Is the black electricians sticky tape staying to preserve originality?
Do you know what the resistor is connected to?
If you can't get a definitive answer I would start with a large value and work down till the voltages make sense.

Re: Mystery 1930s Philco name that Resistor ??
 

400 ohms?

Lawrence.

Re: Mystery 1930s Philco name that Resistor ??
 

The resistor is connected to one end of the mains fuse the other end goes to the Baretter via the other resistors nearby and a 35uf 25v cap

Re: Mystery 1930s Philco name that Resistor ??
 

From that location it's difficult. Possibly it's a chassis connection to a valve cathode?
Really need a more specific location via other resistors and a 35uf cap is not sufficient.
Is there a direct connection to a valve pin?

Re: Mystery 1930s Philco name that Resistor ??
 

If there are similar resistors in the radio you may be able to work out the identification code by comparing the actual measured resistance with the colours.

The resistances originally had a tolerance of 20%, and will probably have changed over time.

There may have been a coding system which became redundant in the 1940s or 1950s.

Re: Mystery 1930s Philco name that Resistor ??
 

Is it an American or British Philco?

Re: Mystery 1930s Philco name that Resistor ??
 

Yes that is what it is I think. The black is not fried, its just black. Philco were very big on resistors painted like this. Notice the white fabric wire above, with the black flecks in it. Philico used this type of fabric covered wire a lot too.

Re: Mystery 1930s Philco name that Resistor ??
 

Is there any chance the model number has been misread, it is odd that there is no reference to it on the web. If so I would think it a good idea is to try and make a definite identification of the radio. Photos, valve list, approximate year, photo of dial, photo of chassis showing layout, can all help identify the radio, just in case there is a similar model.

Mike

Re: Mystery 1930s Philco name that Resistor ??
 

I got took in and thought it was fried, hence my thoughts on value.

Re: Mystery 1930s Philco name that Resistor ??
 

My first thoughts were 470K. J.

Re: Mystery 1930s Philco name that Resistor ??
 

It's eather 470 ohms or 470k- 470,000 ohms.

If it's burnt out like that, it could suggest the lower value but not nesesaraly.

If you look at some examples of 2.2 meg ohm 2,200,000 ohms, (in words) two million two hundred thousand ohms, the whole of the body is red with just a green band arround the middle.

But unfortunatly it doesn't always stay true to form, that the middle coloured band is always the number of naughts. Having said that, useually if it's a DOT it oftern is (but still not always) there were several differnet veriants over the course of time.

It is extremely unlikely, that your resistor of this type would have 7 naughts.

Paul

Re: Mystery 1930s Philco name that Resistor ??
 

The only thing is,you would not normally get a 470K burning up ,hence my thoughts on 470 or 47 Ohms.

Re: Mystery 1930s Philco name that Resistor ??
 

Ok having tested a couple of others it's body tip spot as predicted so if I can work the colours out I'm sorted it's the usual is it brown is it violet routine

Re: Mystery 1930s Philco name that Resistor ??
 

If we knew more precisely the position of the resistor in the circuit it would be possible to give a more accurate answer.

Re: Mystery 1930s Philco name that Resistor ??
 

Right well after cleaning it would appear to be yellow body black tip brown band which I make 400 ohm . The resistor is connected at one end to the fuse on the chassis and via another resistor to the barretter.

Re: Mystery 1930s Philco name that Resistor ??
 

Bias supply?

EDIT: Is the loudspeaker original, if so is it field coil or permanent magnet.

Lawrence.