[TowerTalk] Portable 160M Shielded loop. de K0FF

[K0FF]

Don, K4ZA is headed down to St.. Maarten in a few weeks and was running
short of time to assemble all the equipment, so he asked me to come up with
a suitcase-able version of the 160M SLOOP (Shielded Loop).
The results can be seen at:
http://homepages.dstream.net/K0FF/160/K4ZA

This one uses 20' of RG-8 instead of the CATV hardline, and resonates with
800pF, which is fixed tuned with Silver Micas to 1832 KHz. This
configuration seems to have a higher impedance than the larger cable
presents, so the usual toroid transformer that I would use on here gave less
than optimum results, but by using W8JI's binocular core design, I wound one
for 600 Ohms,and got a near perfect match.

Mechanical aspects were dictated by portability and especially weight. By
using 1/2" PVC water pipe for the spreaders, and an aluminum conduit
pound-in base*, weight was kept at 6 pounds. The longest piece is only 40".
Vibration and rough handling by the airlines is address by shock-mounting
the transformer, and leaving a bit of slack in the leads.

A Pennant Box, K6SE electrical design, constructed with the same vibration
precautions will go along as well.

*note the bang-cap in the photo..this is to protect the threads when
pounding.

73 Geo>K0FF


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