some help with a compatible tube in an acetone amp

[phsyconoodler]

I have an Acetone single ended amp that has a 50H-B26 tube in it.I need to find a compatible replacement as the Japanese tube is near unobtanium.
  I thought a 50L6 might work but the plate and screen voltage in this amp is insane a about 300v and the 50L6 can't handle that voltage.The pinout on the 50L6 is basicallyu the same as a 6V6/6L6,so I may have to use a filament transformer for the heaters,but I was wondering if there is a compaible tube that would work in this amp?
  Anyone that has some experience in this matter? It would be greatly appreciated!

edit: i've decided to just use a filament transformer and a 6v6.it will make life easier.

[drgonzonm]

Did a search on 50H-b26,
 on franks tube I found a spec sheet for the 50H-B26, I noticed that the one of the charts was a 50EH5,  The specs were in Japanese, which I do not speak. Fortunately, someone had scribbled in some English words.   also listed were several other tube numbers.  I did not compare these other tubes to the tube values listed.   The comparison might be worth your time. 

I noticed on a couple of sites, these tubes are being sold for $3.00 each. 

Good luck with your project

[PRR]

Does it have any power transformer now?

50H-B26 appears to be much bigger than 50L6 or 6V6, more like a 6L6.

Do you have any clue what current it runs? (Like, it is working and you can read cathode bias values?)

[drgonzonm]

This is a site that provides some of the data for that 50H-26.

http://tubedata.milbert.com/sheets/084/5/50H-B26.pdf

If you have a schematic please share. 

[phsyconoodler]

I put in the filament transformer and used a 150 ohm cathode resistor,moved the screen voltage so it was higher that the old tube's 150v and it works just fine.I did use a 6L6.
 It indeed has a rather large power transformer but it never worked before cause the tube was shot.
It has a tiny reverb tank inside the chassis that actually works pretty good.
  It's not super loud or crunchy like a champ but it has a nice tone,340v on the plate now and similar voltage on the screen.Sounds fine with the little 8" alnico speakers.

 Very odd tube that Matshushitu or whatever.Very odd indeed.

[bigsbybender]

 Very odd tube that Matshushitu or whatever.Very odd indeed.

Matsushita...  Internationally traded under the Panasonic and Technics brands.

[phsyconoodler]

Indeed.This little amp is a marvelous creation,it doesn't follow any other design standard it seems.Capacitor coupled reverb,that very odd tube and it has killer alnico 8" speakers and an innovative metal tilt-back leg on the back of it.
  I have run across Tiesco amps that are similar but this one is definitely unique.It sounds pretty good,a little like a blackface Champ now,but the reverb adds dimension.
  I just have to track down a hum and get the trem working and it will be a cool little amp.

[PRR]

> Very odd tube

I think it IS a 50L6, in a miniature bottle/base, with a higher dissipation rating. (Most 50L6 will stand over 150V; mostly marketing kept the ratings down to steer you to other tubes for non-radio designs.)

50H-B26 may well be intended for TV sweep work. Big V-sweep or small H-sweep. Being TV market, it could have been very-very cheap the year after it went out of style (perhaps when transistors stole its hole). If it was used only in a few over-worked chassis, the back-stock of replacements might not have lasted through 1970.