"Any new ideas on high performance preamps for 160m?? "
The only thing I can suggest is to build the front end of the
preamp as if it were a JW Miller style crystal radio, followed by the
amp itself. Yep, crystal radio. Those sets had a bandwidth of ~10khz.
Super selective and, yes, on 160m the
Hi Folks
I am following the conversation about LOG RX antennas, I understand the pain
from a noise city lot on 160m. it is hard. I am using Waller Flag's
vertical, since 2006, and horizontal since 2010, however vertical noise is
so bad with new solar panels and EV charges , on top of LED
Hi Roger,
Your loft-mounted small receiving loop is working well, congratulations!
Your somewhat reduced null depth at night is caused by horizontally
polarized signals leaking into the side of your loop. That can
be improved only by locating it near the ground
Well done OM!
73
Frank
W3LPL
Two years ago just for laughs I made up a larger LOG RX antenna. It was 25 feet
on a side. Feed point impedance was high so a matching transformer was
necessary. Output about -30 db.
The pattern maxes out at an angle around 50 degrees but there is some useful
response at lower 160 meter type
Many thanks for the replies (some direct) . . . it seems the LOG IS rubbish.
And Frank, considering what you say, my 6ft Vertical Loop in the Loft works
surprisingly well. It's obviously NOT near the ground, and there is mains
wiring running along the floor underneath it (to the lights in the
Hi Roger,
Any 160 meter receiving antenna laying on conductive soil will have
extremely low RF output and you'll need at least 40 dB of preamp gain
with very low noise figure and you must take extreme measures to control
common mode currents. Antennas NEAR the ground perform dramatically
better
You are correct. It is rubbish. I built it and recorded measurements
because there was so much hype about it. I got exactly what I
expected. A high angle omnidirectional antenna is not a DX receiving
antenna. However if you are into NVIS it actually will improve S/N for
those signals
I just tried making a Loop on the Ground to see if it would be any lower
noise than my 6ft 160m Loop up in the loft.
I followed several people's suggested dimensions . . . so 15 feet each side,
feeding it in the middle of the side pointing West with a 450:50 ohm
transformer . . . And it's
