Re: 80 meter superhet
Hello all again
Very good of you all to take all this trouble for me. I see what you mean about the 11.000 MHz filter being not the perfect tool for the job, but I have made some progress. Regarding the point raised about matching the impendencies at each end of the crystal filter. My original mixer was a diode ring mixer, I spent lots of time trying to get that to work but in the end I gave up and changed it for a 602 mixer. At first that too was no good untill somone sugested I put a toroid transformer in between the mixer and the crystal filter. It was only then that I started to hear the 80 meter band. Regarding the suggestion that I try bypassing the filter to see what happens, I have already tried that and the result is deafening. Of course its mostly broadcast stations, but this leads me to the question does it need a transformer on the output too. If it does then this is where I am at a loss as to what would be suitable. This receiver was built as an experimental set from the begining, that was the whole idea, that is why it is built on the modular principle, it is a test bed for RF circuits. I might have to try another route one day but its all valuable experience in the end.
Regards Mike
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