开云体育

Shielded untuned loops are easy to build and far less expensive than buying one ready-made.? I have two which I built:? 1)? A 2-Meter diameter 2" copper pipe with three internal turns and 2) A 0.5-Meter diameter 0.5" copper tubing with five internal turns which I use for DFing.? The nulls are extremely sharp on the small loop!? The larger loop is mounted up on the hillside just to our east and is used pretty much for VLF/ELF receive.

Again, really simple to build.? Just pay attention to symmetry.

Dave - W?LEV?

On Mon, Nov 7, 2022 at 6:58 PM Bob, N1KPR via <rwbetts=[email protected]> wrote:

Hi Fred; It's non-resonant so it acts like the secondary of an air-core transformer. I had a 48" version for LOWFER work (136 and 472 KHz), but really couldn't see enough signal gain to account for the bigger size. Also monitored Cutler (Maine)signals around 24KHz here in Connecticut (W-J8711). I'm currently using an old Rockwell-Collins RDF 650 Aircraft receiver for LOWFER 472. One of the projects is here:

• ??
  
• Youtube: N1KPR
• Youtube: Ham Radio Doctor

Engineering, where enigma meets paradox

On Monday, November 7, 2022 at 11:01:51 AM EST, Fred Moore <n40cla@...> wrote:

Good morning Bob,

Do you possibly have the same design for 100khz - 500khz?? Basically I think the only difference would be the wire length and maybe the loop diameter.?

Thanks

Fred - N4CLA

On Sun, Nov 6, 2022, 11:58 Bob, N1KPR via <rwbetts=[email protected]> wrote:

I uploaded a triple shield passive loop that is a common monitor antenna for b'cast stations. I use it with a 15-20dB preamp for home entertainment. That gives a signal strength equal to my 160-meter dipole but much quieter. Great for AM DXing.

Bob, N1KPR

• ??
  
• Youtube: N1KPR
• Youtube: Ham Radio Doctor

Engineering, where enigma meets paradox

On Sunday, November 6, 2022 at 04:47:58 AM EST, rinus nienhuis via <dridotcom3=[email protected]> wrote:

searching for a passive? receiving shielded loop for medium wave broadcast band
have somebody a design?
thanks in advance
rinus

--

Dave - W?LEV

Just Let Darwin Work