Topband: WB6RSE Flag type loop question

[wb6rse1 at mac.com]

Mike -

After many experiments, what I came to understand is that a loop is a loop is a loop. They're all variations on a theme. Ground dependent vs independent. Elevation. Size vs capture area. Need for a pre-amp or not. Nearby structures and antennas. The degrees of freedom are many. Some are great. Some so-so. Others just poor performers. The feed point transformer in all cases was critical. N4IS's horizontal Waller Flag up high is apparently very effective.

The original article by Earl, K6SE (SK), in July 2000 QST is an excellent reference demonstrating that the 14' x 29' single loop configuration is optimal for both 160 and 80 with a single value termination resistor. My article adds nothing new electrically, just a more robust mechanical support design after some spectacular failures. Quite a learning experience.

To repeat, the most critical element of the loop is the feed point transformer. Take care when winding it and be sure to bench check it.

The full size loop works well on 160 and 80. I find very little need for a pre-amp. Another option to consider for lower elevations is a vertical Waller Flag. As you likely know, it's two smaller phased loops that fit in about the same footprint. It requires attention to detail when connecting the phasing of the loops and will require a pre-amp.

The flag is the most that I could accommodate on my small West Coast city lot. Now at 200+ DXCC on Top Band and counting, albeit very very slowly anymore.

Good luck!

Steve WB6RSE


> On Aug 1, 2018, at 9:47 AM, W0MU Mike Fatchett <w0mu at w0mu.com> wrote:
> 
> Thanks!
> 
> 
> I think I will still try to build the vertical version to try.
> 
> 
> On 8/1/2018 10:15 AM, donovanf at starpower.net wrote:
>> Hi Mike,
>> 
>> A horizontally polarized loop -- or any other horizontally polarized
>> 160 meter antenna -- has extremely poor sensitivity when installed
>> less than about 0.1 wavelenght above the ground. Even if you raise
>> a horizontally polarized loop to about 0.1 wavelength (50 feet on 160
>> meters) it will be a poor antenna for DXing because of its insensitivity
>> to low angles of arrival.
>> 
>> 73
>> Frank
>> W3LPL
>> 
>> ------------------------------------------------------------------------
>> *From: *"W0MU Mike Fatchett" <w0mu at w0mu.com>
>> *To: *topband at contesting.com
>> *Sent: *Wednesday, August 1, 2018 3:40:10 PM
>> *Subject: *Topband: WB6RSE Flag type loop question
>> 
>>   Has anyone tried a loop like this in the Horizontal plane?   I suppose
>> if one had an AZ mount they could try it from horizontal to Vertical.
>> 
>> His flag build was in the July 2015 QST.
>> 
>> W0MU
>> 
>> _________________
>> Topband Reflector Archives - http://www.contesting.com/_topband
>> 
>