View Single Post
Old 18th Jan 2023, 8:50 pm   #164
AdrianH
Octode
 
AdrianH's Avatar
 
Join Date: Mar 2020
Location: Blackburn with Darwen, Lancashire, UK.
Posts: 1,573
Default Re: Questions on 160/80 metre AM transmitters.

Quote:
Originally Posted by frsimen View Post
You could consider a high pass filter on the output to remove the fundamental when on 80m. You would need to switch it out of circuit for 160m operation, of course.

Paula
Yes that is always possible, but not a simple solution now I have the box built, one other possibility I could try, is to drive it with a 3.6 MHz VFO for 80 metres, that way there would be no 1.9 MHz input and the second harmonic would be at 7.6 MHz which would be filtered out better with the PI network. I could drive it with DDS freq generator I have somewhere in my junk, but a bit of a cheat. I have a sort of idea brewing for a simple mixing type TX, but that will be very much further down the line.

Cheers

Adrian
__________________
Asking questions and learning, or trying to!
Youtube EF91Valve
AdrianH is offline