Hi Simon, apologies for delay in responding to you, I have had some 'technical difficulties' with BT Broadband, but all is well now.
Yes I have seen the circuit to which you refer. It uses a crystal - not a crystal osc pack, which I suspect would give a cleaner output to the mixer.
I have now got 100MHz and 125 MHz crystal osc packs, and a 64MHz crystal. Don't know if its a side-tone or fundamental frequency - not that it matters. I intend to begin experiments some time this week.
Its been many years since I played with rf circuits - got diverted into computers in the mid 70's. So I was right gob-smacked when I went to order some small value silvered mica capacitors (I always used them
in rf frequency sensitive circuits): 12pf ...... £1:20p, postage extra. How much money must I have thrown-given away over the years?
So I have ordered ceramic disc caps instead. Needing them that day, I called into Maplin, having seen they stock all the values I required, and asked the young lad at the counter to get me the caps on my list:
values and Maplin codes provided. He looked on his terminal and told me they only stock one component of each value (3pf, 1pf, 12pf, ....), I said but I need at least two of each part, the reply I got was that they
could order them from head office, and it would take two days or so.
I of course went straight on Ebay, and ordered lots of values in packs of ten each.
So, when my caps arrive, I'll stick a chip onto some plain copper, and try out the circuit.
Cheers and 73 to you.