JohnG3PQA

Hi Martin,
Many thanks for all the info., sounds as if you have built a lot of these loops and noted about the higher Z input needed at higher HF frequencies.
Not had time to finish the loop yet to try the preamp., but if the gain dropoff of the Wellgood from 23dB at 20MHz down to 13dB at 30MHz (measured with 50 ohms in and out) combined with the inductive reactance mismatch is critical, then the Wellgood needs modifying or replacing. BC550s may not be ideal anyway.
I will report back here anyway with results so other readers know how it works with the small design changes and different transistors.
73
John