Again, this unit was purchased from another person. I don’t think that person made any alterations, I can’t see any alterations and nothing looks burnt
I made up a small clip lead to try to short out the diets. This is certainly not optimal, because it will act like a small antenna. But it makes an easy way to allow me to sort out some diodes ?and see what happens
So using my UHF pad, and a bunch of BNC attenuators as well, on 21.02 MHz with Drive at 84% here were the values
fundamental: -6. ?Dbm
Second harmonic: -28 DBM
third harmonic -34 DBM
these are similar to some of my previous measurements for this band which is probably the worst
applying the shorting clips to the input Diode was no improvement and maybe one Db worse
applying the shorting clips to the output diode made a 6 dB improvement at the third harmonic
fundamental: -6 dBm
Second harmonic -29 DBm
third harmonic -40 DBM
I am out of time, so I can’t do much more, but I suspect these numbers would be better with a small short rather than this large clip. However it did not completely eliminate the problem. But it’s another clue. ?
