Need Help Reading Components, 1931 Airline 62-181

[Winky Dink]

After an initial cleanup I'm ready to gather the usual replacement components, but I can't even identify my capacitor values. The only vintage electronics I have any familiarity with is 1950s TV.

The only documentation I have is a Rider schematic with a few notes (Vol 2 Montgomery Ward 2-2) which I've downloaded from three sources, and the best is only partly legible. So I'm trying to interpolate from what I can read on the schematic and the components.

Just for starters, I have three illustrated questions:
Figure 1: I have three resistors like the violet one in the photo--a single body color and no other markings. The two are gray and white. What the value of the single-color resistors?

And how do you read these mica capacitors? On the stack of three in the picture, one has a spot white and a smear of orange. The others have a dash of green on one side.

Figure 2: I assume these are paper caps, but the only marking is a single spot of color. Can the part number hold a secret clue?

Figure 3: I can only guess what's in the box. Is this like a huge multi-capacitor can? Other than the label which I read as "total capacitance 6.02 M.F.," there nothing else written on the outside of the box. Should I just remove the bottom to see what's inside?

If you can help me out with these questions, I promise I'll leave you alone...for a day or two.

- Henry

"There are no stupid questions. But there are plenty of stupid questioners."

Here are some other pictures of the 62-181:
http://picasaweb.google.com/coldrb/A...eat=directlink

[Reece]

So the builder for Monkey Wards wanted to keep everything a secret, eh? Those are part numbers on the paper caps, and unless there were a parts list available listing P/N's vs. values, you'll have to trace where they are in the circuit and compare to the schematic for the values. If the values aren't on the schematics, then I'd compare another radio schematic with the same tubes and similar circuit to see what they used there.

The old dogbone resistors are read with the same color values as today, in B-E-D order, Body, End, Dot. You have to assume that a solid color resistor then is the same color for all three B-E-D. Check it with your ohmmeter. Most don't have to be replaced if they are 20-30% off of their rating, unless in a critical circuit. I don't replace any at the outset unless they are waaay off or burned or broken, of course. However: the resistors MIGHT be following the way of the capacitors and the color is only a "part number" for the mfr. and don't have anything to do with the value, although you've got other resistors with the standard B-E-D system on them.

Got no clue on the micas: aren't they in parallel, by the way, not series, with all terminals at each end connected? Micas are usually the least of your troubles, leave them alone unless the radio doesn't work.

You're working with stuff found in King Tut's tomb here; hopefully the curse won't follow you! Have fun.

[Winky Dink]

I was hoping this would be a little simpler than TV, but no-o-o-o-o! I've started looking at schematics with similar circuitry for clues. Apparently the part numbering system changed in the early 1930's. I have one list which includes an "old part no." column, but it's blank for the components I need. If an all-white dog bone is read W-W-W, then it would be 99 billion ohms. The schematic shows at least two 1 meg resistors which I haven't located yet. This is going to be challenging. I'll start snipping and testing resistors. Also I'll look for someone who has an early 1930's Wells-Gardner set to compare component markings. Thanks.
- Henry

[Reece]

I think I've got a 99 billion ohm resistor or two, if you need it!

[GuyIncognito]

I tend to gravitate toward sets of this vintage, so I have a few years of experience trying to decipher the murky schematics found at the usual online sources. Enclosed is my attempt to mark up the schematic, as best I could.

A couple of values are best guess, but would no doubt be close enough to the +/-20% tolerance to work.

Any corrections cheerfully accepted!

Hope it helps...

[Winky Dink]

Most values agree with my guesses, but I missed a bunch of decimals on the capaci...I mean, condensers! At my level of electronic knowledge, reading a schematic is like translating War and Peace with a Russian-English dictionary. Thanks for the input, especially for taking time to mark up the schematic. This a step in the right direction.