Hi all.
Thanks for all who have responded!
I'm not sure where the "no groundwave signal" stuff started.. I said that
I'd noted QSB on a signal from approx 5 miles away as RF goes on 80m. I
assume that this would be a groundwave signal, as it was daylight at the
time.
Just a quick update on the loop.
I found the 6:1 balun, so connect that direct to the loop, then coax to the
tuner about 6ft long.
It certainly calmed things down on 80m, but there were penalties..
The tuner didn't like it at all on 160m, and there was serious RF in the
shack on 15m.
I think I'll make a 4:1 balun and try that.
The reason for such short feeder runs is that the loop passes 5ft away from
the shack window.
Anyway, the 8ft coax feeder with feedpoint ferrite cored 12 turn RF choke is
back in place as this seems the best compromise at the moment.
Paul MW0CDO.
----- Original Message -----
From: "Paul" <gw7lhi@hotmail.com>
To: <tentec@contesting.com>
Sent: Thursday, January 08, 2004 10:44 PM
Subject: Re: [TenTec] Not TT - Wire antenna question.
> Hi all.
>
> Many thanks for all of your comments, much appreciated and now digested a
> little!
>
> The loop is playing well for me in some respects.
> To my surprise, I'm getting good reports on top band using 25 watts PEP.
> A few days ago, the QRO segment of 160 was alive with North American
> stations.
> Some of these guys were a few dB over S9 with me here, the radio is a
> Ten-Tec Omni V.
> I didn't attempt to call any of them, as they all wanted to work an IZ7
who
> was 40dB over S9 here.
> I used to have a 50m long random wire at a location not far from here, and
> the RX signals from that were not as strong as they are on this loop.. nor
> are signals from my 20m long random wire.
> On 80m, the loop doesn't seem to work well at all. Groundwave TX reports
are
> down to S3 compared to S9 on a ground mounted vertical. I haven't tried
any
> DX or EU on 80m yet. RX on 80m is good, so I assume that TX is lousy
because
> the loop is just over a half wave on 80m.. it's very reactive for sure,
and
> much easier to tune on 160m or 40m.
> On 40m, reports from UK ops are excellent, 10-20dB over the vertical.
> Further afield, reports are mixed, for some the loop is better and others
> find the vertical better.
> I haven't tested any higher bands on TX, the loop loads on them all.
>
> I changed the feed arrangement to some balanced twin feeder to see whether
> the tuning on 80m improved.
> it did, but several other bands became very touchy and there was more RF
in
> the shack than there was with the short length of RG58 with it's feedpoint
> RF choke. The ATU's internal balun started complaining too.
> The RG58 and shield RF choke is back in place now.
> Somewhere, I have a commercial 6:1 balun.. I may try this with the open
wire
> feeder..
> I'm not sure what impedance the twin feeder is, it's grey with stranded
> copper conductors approx 1/2 inch spacing. Not the stuff that comes with
> G5RV's.
>
> The loop is still up in the air on the fibreglass poles, despite 70mph
winds
> and torrential rain last night & today. I note that the tuning doesn't
seem
> to be seriously affected by the wire movements in the wind.
>
> All in all, an interesting wire antenna to play with.
> I'm particularly taken by it's low noise characteristics compared to the
> ground mounted vertical and a 20m long dog legged random wire.
>
> All the best..
>
> Paul MW0CDO.
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