[Elecraft] 160m loop experiment a big failure

[Jon K Hellan]

On 10/17/2011 03:02 PM, Rich - K1HTV wrote:
> Don,
>     How did you plan to use the 160M loop? If you want to work the locals (within
> 500 miles) a low (less than 100 ft high) 160M loop is a great sky warmer. If you
> are more interested in working DX on the Topband then give an Inverted-L a try.

Up to a point, this is true. Given that a loop is possible, you can also 
make an inverted L, and it would work better for DX. A double L may also 
be a good choice. See 
http://www.surriel.com/radio/160-meter-double-l-antenna.

But sky warmers can do very well, too. I don't have trees taller than 4m 
(13'). My lot is abt 600 sq m (0.15 acres). This is actually considered 
large in Europe. There is almost, but not quite, room for a dipole for 
80m. To get on the lower bands, I started out with an inv vee, slightly 
shortened, 15m (45') at the apex and 4-5m (15') up at the ends. I built 
it for a local sweepstakes like contest, but worked 80m DXCC with it. 
(Easier from Europe than from the USA.) Last winter, I wanted to play 
with 160m, and ran low wire to the ends of the inv vee. Seen from above, 
the antenna looks rather like a 'Z'. Result after one season: 61 
countries, including Canada, USA and Tajikistan.

It helps that outside my local area of abt 200k inhabitants, population 
is pretty sparse for  3-400 km or so. There is also no AM broadcasting. 
This makes QRM arriving from high angles less of a problem than it would 
be in much of the USA.

I'm not arguing that you should build a skywarmer where a low angle 
antenna is feasible. But it would be a shame not to try *something*, if 
you can't put up an ideal antenna.

73
Jon LA4RT

>
> I've had very good luck with two that I've built. The one that favors Europe,
> Africa, the Caribbean and So. America has only 30 feet of the 135 feet of wire
> vertical. The rest of it is horizontal, ending up around 50 feet high in a tree.
> This Inverted-L is fed with 50 Ohm coax with a 500pf capacitor in series at the
> base of the antenna.  Presently there are 16 short (1/8 wavelength, 65 ft)
> radials. The second Inverted-L has 60 ft. of vertical with the rest horizontal,
> sloping down to 30 feet. This antenna favors the west and northwest. It has 8
> quarter wave, 130 feet, radials.
>
> Running the K3 barefoot with these Inverted-L antennas, since I've moved to my
> new VA QTH,  I've increased my Topband DXCC total from 201 to 222 countries
> confirmed running 100 Watts or less. Some of the best DX to the east includes
> 4X, S0, 5N, D4 and UA6. To the south CE, CX, VP8/F and to the west FO,
> FO/A,T30,T2,KH6,ZL&  a number of KL7's to the NW. So, as you can see the
> Inverted-L, even without a lot of the wire being vertical, can perform well as a
> DX antenna. It certainly will outperform a 160M loop.
>
> So, if you are interested in making longer haul QSOs on 160M, I would ditch the
> loop and go with an Inverted-L. If you have a tower, I would shunt feed it, but
> that's another story.
>
> 73,
> Rich - K1HTV
>
> = = =
>
>
> -----Original Message-----
> From: goldtr8 at charter.net [mailto:goldtr8 at charter.net]
> Sent: Saturday, October 15, 2011 12:15 PM
> To: Elecraft
> Subject: [Elecraft] 160m loop experiment a big failure
>
> I set up a 160m loop in the yard to try one out from all the great reading I did
> regarding the antenna.
>
> For me I can get it to tune with no problems except the RF in the shack is
> terrible.
> .
> .
> .
> .
> So I thought I would share my current failure while I ponder my next
> move or give up on the loop.   Ok I wont give up, YET!
>
> Cheers
>
> ~73
> Don
> KD8NNU
>
>
>
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