Convert techlib transmitter to use tubes?

[neazoi]

Hello,
Any thoughts of how one should convert this transmitter to use little subminiature pentode tubes?
http://www.techlib.com/electronics/graphics/unfair1.gif from http://www.techlib.com/electronics/amxmit.htm
I just like the loop design, I do not mind is anything else needs to be changed

 

[betwixt]

It would be difficult, the long-tailed pair is straightforward but putting another pentode in the 'emitters' leg would be quite a problem.

If it's the antenna you are primarily interested in, look up "inductive loop antennas" for ideas. For receiving they are easy to construct, I tried one with my 100W transmitter and it generated several KV across it's ends and I had to use quite expensive tuning capacitors to prevent flash over!

Just out of interest, what subminiature pentodes to you have? I built a receiver once using EF74 wire ended pentodes and ran it off a 9V battery.

Brian.

 

[neazoi]

It would be difficult, the long-tailed pair is straightforward but putting another pentode in the 'emitters' leg would be quite a problem.

If it's the antenna you are primarily interested in, look up "inductive loop antennas" for ideas. For receiving they are easy to construct, I tried one with my 100W transmitter and it generated several KV across it's ends and I had to use quite expensive tuning capacitors to prevent flash over!

Just out of interest, what subminiature pentodes to you have? I built a receiver once using EF74 wire ended pentodes and ran it off a 9V battery.

Brian.

Thanks for the answer.
I have the 1j17, 1j18, 1j24, 1j29 and 1j37 all soviet military types. They can operate with 1.2vf and 40-60va.

In the circuit it seems that he sends the signal out of the collector to the antenna through the 8nf caps. I believe I could use any type pf transmitter to feed the signal just right at the common point of the caps, what is your opinion?

I think the antenna the way he has used does not behave like a tuned circuit for the transmitter, he just uses it like a "next stage" in the chain. The circuit could have been followed by an amplifier through a cap connected to the transistor collector.

What if I isolate the antenna from the rest of the circuit and make a standard tube crystal transmitter to feed the antenna?