Filament Transformer for 26 DHT

[korneluk]

folks,

I'm looking for a 1.5VAC 1.5A transformer for a 26 DHT. Any ideas where I may be able to find one?

TIA,

-- josé k.

[Tweeker]

Use a 2.5V transformer and a 2/3 ohm resistor on each side if you must, cuts inrush down too.

[zobsky]

You probably want to use DC on this tube, judging from several reports. So think about using a higher voltage filament transformer, .... rectify, filter and regulate the voltage down to 1.5V.

[korneluk]

No, I am purposely experiementing with AC heating.

[zobsky]

cool, ..let us know if it works out, I have a pair of 26 at home too. make sure you get something that can support the 1A rating of the tubes.

Another possibility is connecting the filaments in series if you can find a 3V transformer (maybe others can comment on how desirable this is)

[316a]

Hi ,
How about a cascade of transformers ? Something along the lines of :

primary:secondary-----primary:secondary------26
115:30-------------------------115:6

That should get you up and running , trim the voltage with series resistors if needed

cheers

316A

[danFrank]

Wind your own; that's what I did. 1.5 vct is a pretty easy job. Get a 5 volt or 6.3 volt filament transformer, unwind the secondary while counting the turns to get the turns per volt ratio. Then multiply that by 1.5 to get how many turns are required for 1.5 volts. Divide by half to get ct.
I am in the process of building Kevin Kennedy's 26 preamp and I have never liked DC on DHT's. I could not find a 1.5vct transformer anywhere so I just wound my own. I made a dedicated winding for each 26 tube. Maybe the hum will be too much , I guess I'll find out!
Good luck, Daniel

[zobsky]

Any results (positive or otherwise) to post regarding AC heated filaments with this tube?