[Lowfer] RX Loop Tuning

[Joseph DiVerdi]

>Paul,
>
>>Using cat 5 wire to bring in the antenna provides one with a certain >measure of noise immunity from feedline pick up. It also gives one 3 >addition pairs of wire to things like motor control.
>
>Yes, the twist in the cat 5 line should help in the immunity factor. What kind of loss can be expected at say 200kHz for 200ft? One time I tried using twisted cable (not cat 5) for sending a square wave to the loop final and found the losses to be high.
>
>I'm a bit partial to the flexibility of the RG-59 coax with F connectors and use it for all TX and RX Lowfer antenna connections. From one of the Hams fests I ended up with a ton of free F connectors and male-male connectors (which also work nicely as panel mounted connectors) Very easy to try out any new antenna ideas, make quick line extensions, burry the line where required, leave it lying on the ground in the woods for months, etc - and the line is very low in loss, including 185k square wave transport.
>
>Thanks for the input.
>
>Bill

Dear Bill,

I've done a bit of experimenting with low-cost wire to convey low-level signals from an active antenna to separately located workshop receiver. I'm interested in lower frequencies (10-100kHz) and toyed around with four-conductor telephone-grade wire. The results can be seen at http://xtrsystems.com/vlf/transmission_line_test .

I found that the driving and terminating the cable impedances affected the loss characteristics dramatically. The limiting factor in my test was the high frequency performance of the transformers.

Best regards,
Joseph

-- 
Joseph A. DiVerdi, Ph.D., M.B.A.          
http://xtrsystems.com/           970.980.5868 (voice) 
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