Terry,
I am looking for a suitable circuit to use with the blown loops
this one might also be worth looking at.
http://www.activeloop.de/html/english.html
Unfortunately I made the silly mistake of using a transmitting
antenna
too close to them
It would be very interesting to hear some more details,e.g.:
QRG of transmitter,TX power,TX-antenna type,
how close was the TX-antenna to the loop?
Was the loop amp on or off when it was fried?
You may guess why I'm so interested in your experience.-:)
We have a ALA 1530 mounted on top of a mast with 2m (50W)
and 70cm (35W) yagi antennas.
The HF dipole (1kW) is about 6m below.
So far the loop amp is still alive...
73
Clemens
DL4RAJ
----- Original Message -----
From: "Terry GW0EZY" <[email protected]>
To: <[email protected]>
Sent: Friday, December 16, 2011 1:18 PM
Subject: LF: RE: Wellbrook Loop
Hi Andy
I use Wellbrook loops - 1530 for hf (150 kHz - 30 MHz) and 1010 (10
kHz - 10
MHz) for lf. They work very well with my SDR-14 and SDR-IQ.
The loop feed box is filled with a potting compound to provide
weather
protection so you can't see the configuration and no info is
supplied with
them. Unfortunately I made the silly mistake of using a transmitting
antenna
too close to them - Wellbrook do not repair them but send a
replacement loop
unit.
On request Wellbrook replaced my 1010 loop with an lf-enhanced
version to
improve response below 10kHz I think by using a coupling transformer
giving
a better lf response but degraded hf response. It seems to work well
as I
can see the Russian Tx at 11.905 kHz and also get good results at
136 kHz.
I'm building a Miniwhip, so will get the opportunity to compare
soon. I can
confirm the benefits of noise reduction. Mine are mounted one above
the
other at 20 feet on a fibreglass pole with rotator (I am building
your
rotator controller for more accurate control as the null is quite
sharp).
I am looking for a suitable circuit to use with the blown loops
(they are
not completely dead but have a serious loss of sensitivity but
disassembly
is certain to destroy the loop amplifier). I suspect it's not so
easy to
form a 1 metre loop with aluminium tubing so the loops can be
re-used for
experiments.
I was thinking something along these lines:
http://www.pm.keirle.com/3_radio/hf_loop_ant/hf_loop_ant.htm
http://www.ik4hdq.net/doc/testi/smlloop.pdf
http://www.vlf.it/looptheo7/looptheo7.htm
http://www.vlf.it/lowfloop/lowfloop.htm
However, I look forward to seeing one of your designs Andy!!
If you need more info on the Wellbrooks please email direct.
73 Terry GW0EZY
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