01-01-2017, 09:56 PM
(This post was last modified: 01-01-2017, 09:58 PM by Murphyv310.)
Hi Mike.
Yes the final one is a three valve version. EF37A, EH90 & 6V6. I always meant to do one with EF86, EH90 and EF80. The 6V6 is just a buffer it's not intended to rump up the power, it just makes the transmitter more linear and reduces distortion in the modulator that various aerials and loads produce. You can optimise the drive to the buffer stage to reduce distortion.
The preamp has NFB from detected audio from the buffer.
I'd need to redraw out the circuit for you. but this online is very similar indeed. http://www.dogstar.dantimax.dk/tubestuf/amtx-3.htm
The buffer stage and feedback components are very similar.
Mine though is crystal controlled, has tuning on the EH90 anode and has a tank coil to reduce harmonics.
Yes the final one is a three valve version. EF37A, EH90 & 6V6. I always meant to do one with EF86, EH90 and EF80. The 6V6 is just a buffer it's not intended to rump up the power, it just makes the transmitter more linear and reduces distortion in the modulator that various aerials and loads produce. You can optimise the drive to the buffer stage to reduce distortion.
The preamp has NFB from detected audio from the buffer.
I'd need to redraw out the circuit for you. but this online is very similar indeed. http://www.dogstar.dantimax.dk/tubestuf/amtx-3.htm
The buffer stage and feedback components are very similar.
Mine though is crystal controlled, has tuning on the EH90 anode and has a tank coil to reduce harmonics.
