03-04-2018, 12:35 PM
Thanks Doug, I'm going to go with a separate receive antenna for now, and that will have to be my 40m dipole until I get something better.
"You didn't confirm whether you had placed the series trap across the coax inner to ground... which is what I would expect you did."
That's exactly what I did. I'll file away your suggestion of a parallel LC circuit for future reference.
Jim
1 I can't hear the second harmonic on a Shortwave portable.
2. I doubt if the engineer actually checked the compliance, but I could be wrong. He actually sent a plan for a trap the size of a 200 L drum, which was overkill to put it mildly. As I said, I now think we're dealing with front end overload anyway, which would explain why there was no QRM with a 40m dipole.
- Jim
"You didn't confirm whether you had placed the series trap across the coax inner to ground... which is what I would expect you did."
That's exactly what I did. I'll file away your suggestion of a parallel LC circuit for future reference.
Jim
(30-03-2018, 06:12 PM)VK3RX Wrote: Interesting.
You earlier said:
Quote:- 50dB attenuation is something like 50mW for a 5kW transmitter
So I'm surprised that would cause such overload at 3km, but then I've never had a BC station so close. Can you hear the second harmonic on a shortwave portable?
I wonder if the station engineer actually measured and proved the station's compliance. I know with the Mildura situation I described the station had to for the then P&T, but in that situation the interference involved the aviation authority so there was a bit more clout.
1 I can't hear the second harmonic on a Shortwave portable.
2. I doubt if the engineer actually checked the compliance, but I could be wrong. He actually sent a plan for a trap the size of a 200 L drum, which was overkill to put it mildly. As I said, I now think we're dealing with front end overload anyway, which would explain why there was no QRM with a 40m dipole.
- Jim