[Lowfer] RX Loop Tuning

Thu, 1 May 2003 12:50:24 -0500

If a guy were to wind the transformers on a ferrite toroid then would the
higher frequency signals transfer with less loss???

Mike>WE0H
http://www.we0h.us/lf

-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of Joseph DiVerdi
Sent: Thursday, May 01, 2003 12:39 PM
To: [email protected]
Subject: Re: [Lowfer] RX Loop Tuning

>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)
PGP Key ID: 0xD50A9E33