Resistors in decade box

[Fresh_Start]

Can someone tell me what kind of resistors these are? 
What's the likely wattage rating?
I'm asking about the long, orange, tubular resistors (not the odd ball carbon comp etc.)



Thanks,

Chip

[eleventeen]

Hey man. Well, hollow like they are, I'd have to say wirewound. The little ones could be as much as 2 watts, that longer one looks like 4 watts. Is this a General Radio box? I ask because if these are the used dudes you bought, I'd tend to think EICOs and Heathkits from that era would use phenolic switches vs. ceramic. And Gen'l Radios are usually all stacked up in a line. If I were replacing these, I would go with cheap resistors, 1, because sub boxes in experimental circuits have a way of blowing the resistors, and 2, the noise performance isn't going to be gangbusters because you have to run the clip leads out to the box anyway.

I notice on ebay there are a few Hong Kong sellers who will sell you an assortment of resistors of every value for a very cheap price. Annoying delivery time, but that would be my choice. Buy one batch and you're pretty much done, meanwhile, you hunt for metal film resistors or whatever the fetish says you gotta have for particular values. Have you seen what people want for regular 1/2 watt, or, Gawd forbid 1 or 2 watt IRC or Allen Bradley or Ohmite (eg; US made) resistors?? Insane.

[PRR]

What they are? Or what they should be for your use?

Personally, unless there are obvious repairs, I would assume 99% of the resistors in there are good AND good-enough. If they read wrong, snip one end and check again. It's just unlikely that "most" of the resistors got toasted.

If you must re-build: 2W carbon-film. I'd be happy with 5% but you may find 2% assortments at a good price.

The reange below 1K, which you may be tempted to use for power tube cathode bias, might be 5W parts, even 10W.

[Fresh_Start]

PRR - actually this thing reads very close to dead-on-balls-accurate 

I'm not touching any of the tubular orange/red resistors.  They're FINE!  Just wanted an idea of the dissipation rating so I could replace the three or four obvious repairs with similar values.  Also, assuming these are at least 3 watts, I can go cheaper on replacement resistors for my substitution box (those values have drifted all over the place!).

Cheers,

Chip

[PRR]

> an idea of the dissipation

Resistor boxes get burned. You want infinite-Watt resistors. The problem is infinite cost. For a few-parts repair, your labor (now and next time) is worth more than the cost of a few Watts. So go high until cost gets silly or size is a problem.

I forget what those parts used to be rated. I think it was low-tech at the time. That it was some old hand-winding jig which could not compete on cost with machine-made 10% resistors, but could hold 1% tolerances on small runs at low price.

If it was ceramic, it is clearly 2W-5W, but the resistance could shift more than 1%. And they may be paint not ceramic. And they may "work" with the paint burned off, until corrosion rots the wire. So I think you were supposed to keep them well below 1W. But I think you can buy 2W 2% ceramic-skins for pennies now. And if they drift another 2% when glowing dull-red, you don't much care in tube-work.

BTW: did some digging by the garage. We knew there were rocks. Found boulders the size of an engine. And a tractor tire-chain. And a mooring/logging chain. Then the rear bumper from a pickup truck. Hole big enough, excavator went home, I see a "pipe" at the edge of the hole. I chip away, there's a clutch housing. With a flywheel. And then I found much of an oil-pan. I knew where this was leading. Pulled out a 1950 Chevy Six, 215CID, 92HP (if it only had a head), dip-oiled. The flywheel was no more than 3" under the surface.

[Fresh_Start]

FWIW the bright orange tubular resistors are labelled "0.25%" and are still within that spec.

Chip