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Varicaps definitely can rectify and create QRM from strong signals, be they AM BCB stations or nearby ham stations or if you are running SO2R. The back to back configuration helps but you can still

> >Hi all, I'm experimenting with various remotely tuned open air loops and ferrite loopsticks. I have made >a remotely tuned varicap diode assembly and a remotely tuned variable capacitor assembly

Hi all, I'm experimenting with various remotely tuned open air loops and ferrite loopsticks. I have made a remotely tuned varicap diode assembly and a remotely tuned variable capacitor assembly (using

Applicable to receive loops? http://edn.com/design/analog/4430051/Differential-amp-has-6dB-lower-noise--twice-the-bandwidth Discuss...

What are you saying, that the loop will work better with the center conductor attached, or what.

A loop antenna primarily responds to the magnetic component of a radio wave. An unshielded loop will also pick up some of the electrical component, and not necessarily in a symmetrical manner. If you

Garey wrote on April 17. Guys: “Wondering what the "advantages / disadvantages" are for a Shielded Loop vs a non-Shielded Loop for the same Loop DIAMETER. I have a "feeling" that one has a better

Some of the advantages are low frequency noise immunity and isolation from nearby objects. I have a section on the noise immunity on my paper on shielded loops in the group files section. Chris Trask

Guys: Wondering what the "advantages / disadvantages" are for a Shielded Loop vs a non-Shielded Loop for the same Loop ?DIAMETER. ?I have a "feeling" that one has a better "Q" than the other -

Guys, One of the best things that I have found is PAP pipe ( polyethylene - aluminum- polyethylene). I found some 1" on eBay and have used it to build both a 1 meter loop and a 6' diameter shielded

PVC wouldn't be good for Q. An HDPE jacket would be far superior. Maybe there's irrigation pipe available with suitable diameters?

There may be an indirect advantage. With the bulk resistance reduced, the Q of a series-tuned loop would i

Brian, That would be an interesting construct for a shielded loop. Chris Trask N7ZWY / WDX3HLB Senior Member IEEE http://www.home.earthlink.net/~christrask/

Chris, We used 6mm copper tubing with a bonded PVC jacket for instrumentation lines at work, 10mm overall diameter so that would fit nicely down 15mm copper water pipe as the loop Just a thought. 72,

Thanks for the articles Chris. My present 10' shielded loop is used only for the BCB and below so much of this would likely not affect my system as much as if it were to be used on higher frequencies,

I sent you a couple of files to illustrate how the loop element diameter and frequency affects the efficiency of a non-shielded loop antenna. The results can be extrapolated to understand the effects

Thank you Chris. would it be something one could notice (measure) on a 10' loop? My present 10' shielded loop uses RG-58 and going to RG-8 or RG-11 would really increase the weight. Is it something

When I did my in-depth work on loop antennas, I found that as the diameter of the element (NOT the loop diameter) was increased, the efficiency improved. This was a result of the larger cross

I recently read of one claim for greatly improved performance of a shieled loop when changing from RG59 to 3/4" hardline for the loop....same diameter. The conclusion was that the much larger center

Hi Chris. For sure it's a very good preamp but it implies too much coils for me. I have some toroid but can't identify them. Unless you have one readily made for sale. I forgot to mention that my band