neazoi
Advanced Member level 6
Hi, I have a wire antenna for TX and RX for my rig (HF 100W), but now I want to use a separate antenna for RX (loop).
I have only one coaxial through the wall and I cannot pass another. There is no remote power source (on the antenna side).
The only simple way I think this can be done is through a phantom power through the same coaxial on the RX.
A phantom PSU for RX is simply an LC block with the L being large (eg 1mH) so that no RF escapes to the PSU.
But if you want to switch TX and RX antennas there must also be a relay to switch between them. A system is proposed in the attachment. Note my TRX outputs VCC at a control pin on TX, so I added an inverter there cause I want the opposite)
The problem is that the remote relay coil stays connected to the line during TX also, with unpredictable results.
What solutions can I find for this. Somehow to isolate the line during TX? Latch type relays are ok if they are of any good.
Maybe just add a 1mH before the remote relay coil (as shown in the attachment) is enough? We are talking about 100W of HF power, can this effectively isolate the RF from flowing to the GND through the relay coil?
I have only one coaxial through the wall and I cannot pass another. There is no remote power source (on the antenna side).
The only simple way I think this can be done is through a phantom power through the same coaxial on the RX.
A phantom PSU for RX is simply an LC block with the L being large (eg 1mH) so that no RF escapes to the PSU.
But if you want to switch TX and RX antennas there must also be a relay to switch between them. A system is proposed in the attachment. Note my TRX outputs VCC at a control pin on TX, so I added an inverter there cause I want the opposite)
The problem is that the remote relay coil stays connected to the line during TX also, with unpredictable results.
What solutions can I find for this. Somehow to isolate the line during TX? Latch type relays are ok if they are of any good.
Maybe just add a 1mH before the remote relay coil (as shown in the attachment) is enough? We are talking about 100W of HF power, can this effectively isolate the RF from flowing to the GND through the relay coil?
