Chris Mike JNT et al - So this piqued my measurement interest
This evening running circa 2W ERP at 137kHz 1Kw from Decca 5501, I measured the following:-
Ve7sl clone 10ft diameter screened mag loop burhans amp at 50ft from 500ft circumference tx loop gave plus 13.2dBm into terminated 75ohms W and G SPM30 (oerrr!) - this is normally connected via a 6dB pad to an Icom R75 without issue to date. Amp appears to have a lot of "head room"
And -8.4dBm from an LF engineering L400b probe at 150ft or so
Interesting
Laurence KL7L WE2XPQ Wspr 2 136kHz till dawn
Laurence, Chris & All: I did a test with
my eprobe which is about 30 feet away from my HF elevated ground plane that has
65 ft radials a few years back. With 100W output on 40 meters. I was getting 1mw
of RF power from the eprobe into a Boonton RF voltmeter. I was using a 1 inch
wide by 12 inch long brass strip as the eprobe antenna at the time. I
would assume the eprobe may be able to generate more power than that at higher
nearby transmitter power levels. Suitable overload protection for a
receiver front end would appear to be prudent.....
73, Mike wa3tts
----- Original Message -----
Sent: Wednesday, October 14, 2015 2:56
PM
Subject: RE: LF: PA0RDT antenna near a
TX? Front end OK?
Chris I run up to 1Kw on 136kHz and up to 400W
on 475kHz and "alive" Eprobes (L400 and PA0RDT variants) about
100-150ft away up at 30ft plus and not blown them up. They don't like it
much of course and produce unwanted products during Tx but that not
surprising. Only FET failure to date has been down in Oklahoma
from a nearby lightning strike. Laurence KL7L et
al
> > > If I mount my PA0RDT clone on my mast stub, about
50 feet from my LF > TX'ing aerial, is it likely to be damaged if
powered on when TX'ing? > > Thanks. > Best
regards, > Chris mailto:[email protected]> >
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