Hey Everybody. Happy 4th of July Independence Day!!
I have a heathkit DX-60 I have been using some on AM, just mostly getting use to it. I really like AM its got a very nostalgic feel and I love tubes. I have read a lot of the tech post regarding the DX-60 and have got the bug to build and external modulator for it. I have found several schematics and articles for one of the modulators. One uses 6DQ6gt's and I really like it as I have a lot of DQ6 tubes. And another uses 807's which I do not have. My background. I have built and repaired many amplifiers from 4cx250 tetrodes to 3cx3000 triodes. So I have enough basic knowledge and experience except on the area of modulation transformers. Both of the Modulator units I have found use Mod transformers that I cannot find anywhere.
The 807 Mod unit I found on here in an article and it uses UTC s-2 and a Stancor A3892 30 watt transformer. The 6DQ6GT uses a Interstage transformer 1:3 primary-to-secondary ratio Thordarson 20A22 and a Modulation transformer, 4000-4000 ohms UTCS-19. I cannot find anything like these. So where do you folks find your transformers?
Do you know any substitutions for these?
Can you run Mod transformers back to back to get your correct impedance? Such as a 4k ohm CT primary with a 12 ohm secondary, 2 of these transformers with the secondarys tied together to have 4k ohm to 12 ohm to 12 ohm to 4k ohm? if that makes sense to you.
this is an article with the 6DQ6GT's I am sure some of you have seen it before. Like I said I am a Newby so I will probably ask lots of dumb questions. All input is appreciated.
https://www.robkalmeijer.nl/techniek/electronica/radiotechniek/hambladen/qst/1955/12/page26/index.htmlThanks & 73
KK4RSV
Darrell