I hope they have better protection from large RF signals shorting out the LNA. I have to replace my LNA 4 time now. The FCD didn’t like the strong RF in my ham shack. I’m running +500 watts on 439Mhz ATV with 100db of isolation and it still takes out the LNA. I had to put a shorting RF relay at its input to keep it from taking out the LNA.
Too bad you can’t make it more than 180khz wide. It would be nice to have 4 to 6 Mhz detection bandwidth. for the new
Digital Ham TV coming out here soon.
Thanks for your note. The front end is completely different in the FCD+, among other things it uses a completely different LNA. However I’m surprised you’ve had difficulties with your front end, I am only aware of 2 or 3 of the original units having LNA faults out of many thousand, and when I opened them up to repair them it was clear that quite a bit of RF had been pushed in there directly. There are protection diodes placed right on the LNA. At 430MHz, unless you get the electrical position right a shorting RF relay might not help.
As I am sure you know, the FCD and FCD+ are designed for narrowband transmissions, so 180kHz is more than enough for that.
I hope they have better protection from large RF signals shorting out the LNA. I have to replace my LNA 4 time now. The FCD didn’t like the strong RF in my ham shack. I’m running +500 watts on 439Mhz ATV with 100db of isolation and it still takes out the LNA. I had to put a shorting RF relay at its input to keep it from taking out the LNA.
Too bad you can’t make it more than 180khz wide. It would be nice to have 4 to 6 Mhz detection bandwidth. for the new
Digital Ham TV coming out here soon.
WB8LGA
Charles
Hello Charles
Thanks for your note. The front end is completely different in the FCD+, among other things it uses a completely different LNA. However I’m surprised you’ve had difficulties with your front end, I am only aware of 2 or 3 of the original units having LNA faults out of many thousand, and when I opened them up to repair them it was clear that quite a bit of RF had been pushed in there directly. There are protection diodes placed right on the LNA. At 430MHz, unless you get the electrical position right a shorting RF relay might not help.
As I am sure you know, the FCD and FCD+ are designed for narrowband transmissions, so 180kHz is more than enough for that.
Many thanks, Howard