[Lowfer] LF receiving loop

[Dexter McIntyre W4DEX]

Zack,

I can't comment on that preamp design but I had great results from Lyle's
balanced loop preamp:

http://www.lowfer.us/k0lr/bal-pre/bal-pre.htm

Dex

On Tue, Nov 6, 2018 at 10:37 AM Zack Widup <w9sz.zack at gmail.com> wrote:

> I finally got done with a project that has taken me a couple years in my
> "spare time." I made a 20 turn LF loop, 5 feet on a side, with turns spaced
> 1 inch apart on a pvc "X" form. And I built this remote tuner/preamp:
>
> http://www.lowfer.us/k0lr/preamp/preamp.htm
>
> It's the second schematic, with the four varactors, that I built. I used
> MVAM109 diodes. I also added a set of switchable parallel capacitors to the
> circuit. allowing me to add capacitance from 100 pF to 6400 pF in powers of
> 2. I also placed taps on the loop, at 3, 5, 10, 15 and 20 turns so I could
> select smaller inductances.
>
> I got around to trying it out last night. I was not happy with the results.
> The tuning appears to occur where I expected it based on some calculations
> I made. But the signal strength is on the weak side. I tuned part of the AM
> band and saw signal strengths far below what I'd hoped for. Only a coupe
> local stations moved my s-meter. I am getting stronger signals from an HF
> vertical (MFJ 1796).
>
> I am using 100 feet of Micro-8X coax cable between the remote tuner box and
> the receiver in the shack. I don't know if that's part of the problem or
> not.
>
> Does anyone have any experience with this?
>
> 73, Zack W9SZ
>
>
> <
> https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon
> >
> Virus-free.
> www.avast.com
> <
> https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link
> >
> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>
> ______________________________________________________________
> Lowfer mailing list
> Home: http://mailman.qth.net/mailman/listinfo/lowfer
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Lowfer at mailman.qth.net
> Post must be less than 50KB total for message plus attachment!
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>