directly heated valves

[jplebre]

Maybe not the right forum (but I like it here - it's cosy!

What's the deal with directly heated rectifier tubes? It means adding 5v (depending on the tube) AC voltage on the rectified side.
Doesn't this add up to the ripple? I mean the wave will have un-even peaks.

A little suggestion could we have an area of the forum for random tech questions like these, not actually associated with a specific design?

Thank you
J

[amptramp]

Some power transformers have centre-tapped 5 VAC windings just to accommodate designs that cannot tolerate 60 Hz modulation.  As a collector of antique radios, I have run into several Rogers sets that used a pair of 2X3 rectifiers to increase the tube count - but they never capitalized on the ability to eliminate 60 Hz by taking the raw DC from the heater tap (both heaters were 2.5 volts and were run in series from a 5 VAC winding).

[PRR]

On another forum some guy and I disputed this. I said there was extra 60Hz and he thought there wasn't. He actually measured the effects. In any practical case the superimposed 60Hz is really too small to matter.

[jplebre]

capitalized on the ability to eliminate 60 Hz by taking the raw DC from the heater tap (both heaters were 2.5 volts and were run in series from a 5 VAC winding).

Do you mean AC?

when you said in series, both rectifiers in series because they are only half wave rectifiers?
http://www.r-type.org/search.php?zoom_query=2x3&zoom_per_page=10&zoom_and=1&zoom_sort=0
Just can't find info on the 2x3. Some people referred to 2w3

[amptramp]

Try this page:

http://www.mif.pg.gda.pl/homepages/frank/short/054/0/001.pdf

Rogers sets used a lot of interesting tubes that no one else used.