[Lowfer] Band conditions

Mon, 14 Oct 2002 09:38:10 -0400

Jay, 

Yes I would be interested in your results.

----- Original Message ----- 
From: "Jay Rusgrove" <[email protected]>
To: <[email protected]>
Sent: Sunday, October 13, 2002 12:56 PM
Subject: Re: [Lowfer] Band conditions

> Larry
> 
> Thanks for the capture. Glad to see VD is good copy there.
> 
> Yes, my loop is pointed east/west.
> 
> I have used my TX loop for receiving and measurements this summer on TAG
> and WA shows about a 1 to 2 dB s/n advantage over my 17 turn, 5.5 ft per
> side tuned box loop. I find that about 24 - 28 dB of attenuation between
> the TX loop and the receiver input is required. Otherwise, the
> background band noise activates the receiver agc.
> 
> A couple weeks ago I installed a single turn 100' diamond shaped RG-58
> loop untuned receive antenna. It's set up with the braid as an
> electrostatic shield - at the top of the loop there is a 1 inch gap in
> the braid. The free ends at the bottom of the loop have N connectors
> that attach to each side to an aluminum box. The primary of a broadband
> transformer has one end connected to each of the center pins - at the
> moment it's "floating" with no connection to ground. The secondary of
> the transformer feeds a heavy duty bipolar (50 mA idling current!)  2.5
> dB noise figure 50 ohm broadband fedback preamplifier. DC is fed to the
> preamp via the output coax. The transformer I'm currently using has 5
> turns on the primary and 25 turns on the secondary wound on an FT-37-75.
> 
> Haven't had time to do complete testing or optimization of the
> transformer, but it works pretty well as is down to at least 10 kHz. The
> electrostatic shielding removes much of the local noise and s/n
> measurments on TAG and WA look promising. At the moment the bottom is
> only about 3 feet off the ground. I'm going to try elevating it to 100
> feet at the top. Also plan to try a similar antenna with 200 feet of
> RG-58.
> 
> If you're interested I will let you know what I find as I do more
> testing.
> 
> Jay
> 
> 
> 
> Larry Putman wrote:
> 
> > Hi Guys!
> >
> > Here it is 11am and VD is blasting in and if you look
> > carefully in the upper left corner there is WA.
> >
> > I suspect that in a month or so WA will be stronger yet
> > during the day.
> >
> > Bill are your loops still rotating?
> > Jay did you tell me your loop was favoring east/west?
> >
> > If Dex would join you on this freq I am sure he would be
> > on this capture also.( Hint )
> >
> > Since these TX loops seem to be doing such a good job
> > would a loop built similar to the TX loop work better
> > as a receiving loop also??
> >
> > I know that Mitch's 12' Octo loop is doing a fantastic job so
> > what would a very large coax loop do?
> >
> > Larry WB3ANQ
> >
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