widow maker ethics question

[Leo_Gnardo]

Can someone help me figure out what rating iso transformer and line fuse I would need for this? It is marked 30 watts on the label, and curiously "Volts 117 AC/DC 60 cycle".

Power law P=IV tells us current will be about 250 milliamps. Makes sense because your typical filament is 150 mA and the remainder should be enough to let the pre & power tubes do their biz. Now don't forget, there's always a startup "bump" in current so I'd pick an isolation transformer that will handle double the average, or 500 mA, also fuse the system with a half amp slo blo. You may find iso transformers rated in VA, in that case 60 VA would be a good pick.

[Enzo]

Fibber McGee and Molly does get tiring, though not nearly as awful as Mary Foster, Editor's Daughter.

Tune to a newer station and listen to the Bickersons. I swear the wife and I do their bits all the time.

[g1]

If it is half wave rectified, you will need to over-rate the iso-transformer.
I think Leo's over-rating factor would suffice.

[Leo_Gnardo]

Fibber McGee and Molly does get tiring, though not nearly as awful as Mary Foster, Editor's Daughter.

Tune to a newer station and listen to the Bickersons. I swear the wife and I do their bits all the time.

I never get tired of Fibber McGee & Molly, nor the rest of 'em. In fact I'm listening to WVKR's Sunday program, 3 hours of old radio from 6 to 9 PM, and you can pick it up on your computer if not within FM range. "The Fat Man" is on right now, it's always a hoot to hear "Bulldog Drummond" or "Archie & Jughead", and you can't go wrong with Groucho Marx and "You Bet Your Life."

Onto important stuff, Randall here's a couple choices from Mouser, I'm sure any will do for your purpose:

power transformer Isolation Transformers 115 V Power Transformers | Mouser

[Enzo]

I used to listen to an hour of it every night on WBBM Chicago online streaming. the syndicated show was When Radio Was. Some comedies were sharp, and others less sophisticated than even Hee Haw. I wound up liking Yours Truly, Johnny Dollar, a detective show series.

[Steve A.]

So the question in my mind is this: was the hum fixed?

FWIW when asked to do something technical like this which raises ethical questions sometimes it is easier to say that you don't know how to fix it rather than you don't want to fix it, explaining the reasons for your decision. Play dumb- it seems to work well for at least some of the Presidential candidates...

Steve A.

[Randall]

I went with the Triode N 68X, 50 VA. Thanks everyone!

[g1]

I went with the Triode N 68X, 50 VA. Thanks everyone!

Can you get back to us as far as how warm/hot the transformer gets in service?

[Randall]

Can you get back to us as far as how warm/hot the transformer gets in service?

I sure will.

[Leo_Gnardo]

I went with the Triode N 68X, 50 VA. Thanks everyone!

The price is very affordable & you're putting it in a metal enclosure, right? All will be good I'm sure.

[Randall]

Yes on the 5" x 4" x 3 " aluminum enclosure, think I should poke some vent holes in it?

[Enzo]

For appearance and professionality, make a hole then snap in a vent plug.

Mouser stocks this line of such items:
http://www.mouser.com/ds/2/184/5-01_115-909189.pdf

[rjb]

For appearance and professionality, make a hole then snap in a vent plug.

Ghetto Version:

Master Flow 2 in. Resin Circular Mini Wall Louver Vent in White (6-Pack)-RLSC2 - The Home Depot

[Randall]

Here it is finished. Electrolytics replaced, in line iso transformer in aluminum box, grounded AC cord. Hum is gone, all cleaned up, and working well. The iso box gets somewhat warm, I did punch some holes in the top and bottom, but less so than the plastic cabinet of the radio. Customer is very happy, his wife has her radio back. Thanks for all the help as always!

[loudthud]

Most of these things are what was called the "All American Five". Five tubes and AM only. This one has FM too. How many tubes does it have?