Aerial for 500 is a loop 30 feet by 20 feet. TX gives 150 watts RF and so far my furtherst QSO is with G3GNR in Devon who gives me 559 at times.
TX: There are four 807's in parallel/push pull with 600 volts on the anodes. The only solid state bit is the VFO on 8 megs, divided down - the driver is a 6L6. The ATU is on the right hand side, and is just two small variable capacitors to resonate the loop, so nothing fancy. The HT comes from two separate power supplies in series, The big control in the front is a variac which feeds the primaries of the transformers so that I can get exactly 600 v. HT - I don't want to blow up the 807's RX:FT 950 with home brew pre-amp. Small TX loop for RX aerial. On 8 Nov 1009 at 2250z on 507.7 kHz John reported VX9MRC was 339. [First Scottish reception of Canadian 600m experimental signals]