A nice big piece of Pye

[Jon A.]

Originally Posted by MadMan

The real question is, how do you plan to print the new dial onto the glass?

I've heard of printing on clear acetate film and sticking that to the glass, and I don't recall saying what you quoted.

[old_coot88]

Originally Posted by Electronic M

....The 'outside foil' band on the end of paper caps is traditionally connected to ground. The outside foil wraps around the cap shielding it (thus why you want to connect it to ground...

Not necessarily. If shielding is your concern, the outside foil needs to go to the lower impedance side, which is not always ground. For example, the coupling cap from plate of a 1st audio stage to grid of output stage. The outside foil goes to the plate because it's lower impedance (albeit higher DC voltage) than the grid.

Signal impedance is what you're shielding for.

[Jon A.]

Originally Posted by MadMan

Yeah I thought that was a great idea to make sure to minimize interference in my stuff when I'm recapping. But then I tried it, and came to realize that you need a super-accurate/sensitive scope to be able to figure out which lead is the outside foil. So like... I figure now if my scope isn't sensitive enough to tell the difference... why bother?

I've ordered from justradios before, their parts seem to be decent quality. But the $25 minimum sucks, so if you miss something in your order you're fucked.

I've used capacitorworld too. They definitely sell cheap shit. And they have a bad tendency to screw up my orders, and they have NO customer service to speak of. But anyway, the way I see it, most old paper caps have a tolerance of +/- 20%, and most modern film caps - even the cheap ones - are usually 10%.

Idk. Also - noice radio!

As I said above there are quite a few videos on testing for the outside foil, but only one I know of is really useful, and from what I saw an older scope should work just fine.

Yeah, the minimum order thing sucks, that's even worse than missing a part and having to cough up the extra shipping charge.

As for Capacitor World, I'm not the least bit surprised.

Yeah it is a pretty cool radio. Most antique table radios I've seen are a lot simpler and a lot smaller.

Okay, now I'm pretty torn as to which resistors to choose. Someone recommended Vishay metal film resistors a while back but I'm not sure how to go about stepping up the wattage.

[madlabs]

I like metal oxide resistors with the metal film ones for higher values. Just bump on wattage up, so for a 1/2 watt get a 1 watt etc. This is not for wattage but for physical size and voltage rating.

[maxhifi]

I understand why one would want to buy the good stuff, like real orange drops. But the bulk ebay brown drop caps have saved me tons of money, and I haven't had a single failure. I wouldn't use them in something valuable, or critical, but for old tube radios, PA amplifiers and other such applications, they are great. It's also nice to have all the values I need in stock, all the time, for minimal cost.

See attached how I organized them (box not from ebay) . Everything in that box cost me under $50, I've refilled the 0.047s and 0.1s a couple times but the rest are still from the initial order.

[teevee]

Mouser is my go-to for caps. I usually order enough to get the price breaks, I don't think they have a minimum order, but I get enough to make the 8$ shipping worthwhile..

[Jon A.]

I looked up my old thread and it was Bob Andersen who recommended the Vishay metal film resistors and he posted the link below. If he likes them then they must be good. Besides, metal oxide resistors are a bit hard to come by in the values I need.

http://www.mouser.com/catalog/catalogusd/646/817.pdf

[Jon A.]

Okay, just a couple more resistor questions; this radio uses mostly 1/2-watt resistors so I have most picked out.

1. Is a 3-watt resistor of about the same physical size as a 1950s 1-watt a suitable replacement?

2. There's a massive 18k 2-watt, ~30mm long carbon comp in there, what can I replace that with?

3. What is the modern equivalent for a 1.6k, 4-watt power resistor?

[madlabs]

https://www.mouser.com/ProductDetail...dji2uRYA%3d%3d

This should work for the 1.6K

https://www.mouser.com/ProductDetail...dji2uRYA%3d%3d

A little smaller than 30mm, 25mm.

Are you using 1 watters for the 1/2 watters?

[Jon A.]

Originally Posted by madlabs

https://www.mouser.com/ProductDetail...dji2uRYA%3d%3d

This should work for the 1.6K

https://www.mouser.com/ProductDetail...dji2uRYA%3d%3d

A little smaller than 30mm, 25mm.

Are you using 1 watters for the 1/2 watters?

That 1.62 looks good, thanks. Edit: Oh shoot, that's a non-stocked item.

The same link was pasted twice; I've made that mistake many times. Actually it's the 18k 2-watt carbon composition resistor that's about 30mm long; I have no idea what to replace that with. I'm using 2-watt resistors to replace the old 1/2 watters. Bob Andersen said he does this, they're approximately the same physical size.

To sum it all up I plan to use 2-watt metal film resistors in place of the old 1/2 watters and 3-watt to replace the old 1-watters as they're very close in size. I have no idea what I'll do about that 2-watt carbon composition fatty or the 1.6k 4-watt resistor.

I got a close-up of the circuit the 1.6k 4-watt resistor is in, highlighted it and identified the tubes in the area, hopefully that helps.

[madlabs]

Dang. I thought I checked the non-stock option. Grr. I do see that Mouser has a 10 watt, 1.6 k in stock. If you can do 1.5K Mouser has plenty of in stock options and that is a less than 10% difference. What is the tolerance of the original part?

Here is a 18k, in stock and 25mm.

https://www.mouser.com/ProductDetail...reHfLvJIcaE%3d

[Jon A.]

No can do, tolerance is 5% and I wouldn't feel safe going lower. I believe it's a wirewound resistor; I suppose 1.8k 5w will have to do in this case, it's about as close as I can get. As for the 18k resistor I suppose I'll go with the Panasonic 3w metal oxide.

If that's all in order I now just need a source for dial string, 6.5V 0.3A indicator bulbs, tuning condenser grommets and a dial pointer like the one pictured which is the usual grossly overpriced eBay item. The ad says it's 4 3/4" long which seems appropriate for this radio and the carriage looks like the one in the dial stringing instructions.

[MadMan]

It's just a piece of metal. Can't be that hard to make.

[Jon A.]

Yeah, some 18 gauge bus wire ought to do it. I just have to finish figuring out the bends needed to mock up a pointer carriage.

Now, is there a one-stop shop for the bulbs, grommets and dial string?

[madlabs]

How about two 3.3k, 3W in parallel? That gives you 1.65k.

https://www.digikey.com/product-deta...W-3BK-ND/36825