[hpsdr] Transmit on HPSDR

[Luke Steele]

An antenna T/R changeover switch could be as simple as a single pole
changeover relay. Any relay would work, but the PCB power relays are good
for several hundred watts. The relay could be switched via Penelope's T/R
control pin on the DB-25 connector.
However, I read that Pennywhistle has no low pass filtering, so you would
be at risk of harmonic emissions. An outboard PA with LPF could take care
of that.

In my setup, I've used a 100W PA block intended for a commercial HF
transceiver. It has the T/R switching, LPF, ALC and high SWR protection. As
mentioned before, a PA assembly from a broken HF transceiver would do the job.

On the receive side, I find that I have sufficient selectivity in my
antenna systems to not need band pass filtering on the front end.

Good luck,
Luke VK3HJ

 1294715447.0