Glenn,
Yes, 1N4007 performance as PIN at 30 MHz in that regard is not great. The measurements documented on the page below suggest around 6.5 pF at 10 MHz with some modest level of reverse bias, which seems in line with the datasheet. I wonder whether this issue - even with the original PIN diodes - was the reason that Drake included two in series in the receive path?
As my junk box has no PIN diodes in it, I shall check to see what can be purchased.
Regards,
Mark, G4FPH.
