Re: [loopantennas] Re: c-crane dual coil antenna?
- Hi Kevin,If you will look in the files section I have several articles that I have posted that will give you a lot of information on multi-coil loop antennas, where I have made various configurations with 2 and 3 coils in parallel as well as a Pollydoroff configuration. All of the various configurations, using more that one coil have made an improvement in performance over that of a single coil. Most of the experiments were done on either a Ferrite Sleeve Loop (FSL), or on Sstacked Toroid Loop Sticks (STLS). You will find them listed under my everettsharp74 email address. However, I do not use that address as my primary address, it is everettsharp (at) aol.73's Everett N8CNPIn a message dated 7/5/2013 9:42:10 A.M. Central Daylight Time, mckeetajc@... writes:
I would much appreciate it if you would supply links to a site or two where one can learn more about Xtal set builders use of multiple air-wound coils in the same plane.
--- In email@example.com, kevin asato <kc6pob@...> wrote:
> It's similar to what xtal radio developers have been using - multiple air-wound coils in the same plane to help increase sensitivity to their crystal sets. The use of the ferrite bar allows a reduction in the coil size. Difference is that the crystal sets do not fix the position of the coils to allow for fine tuning of signals. I do similar using a Terk Advantage coil with my portable radios. It works but it is not a miracle worker.
> From: Don <stb55@...>
> To: firstname.lastname@example.org
> Sent: Thursday, July 4, 2013 5:03 AM
> Subject: Re: [loopantennas] c-crane dual coil antenna?
> Hi Steve,
> Thanks! I did not know you did that investigation. I bought one a couple
> of years ago to hopefully improve the AM reception of my stereo in this
> metal can. The "twin-coil" was also about half price. Anyway, it did not
> help/improve reception in my case.
> Don KPC6NDB
> Upland, CA
> 34.10 -117.63 1250ft
> R-75 w/250Hz 2x R-71A w/250Hz R-70
> Perseus SDR-IQ FUNcube Dongle Pro+
> FRG-100B DX-1000 SR-AF & LPF
> DSP599zx MFJ-784B HD-1418 AF-1
> MSB-1 PA0RDT Mini-Whip x2 @ 20ft
> RYO Active Antenna @ 20ft
> LFL1010 ALA100L x2
> On 03-Jul-13 22:36, Steve Ratzlaff wrote:
> > This same topic came up several years ago. At that time I bought the
> > Twin Coil antenna and tore it apart and tested it extensively on the
> > bench. I used both the original twin coil then replaced it with a single
> > coil. In all tests, there was no significant difference, if any
> > differences at all, between the two configurations. And reading the
> > patent, there are glaring errors seemingly purposely inserted to try to
> > fool the unwary. It's a good antenna for its 7.5" ferrite rod size and
> > works well and I recommend it if one needs a 7.5" ferrite rod remotely
> > tunable antenna. But if you homebrew your own using a similar 7.5" rod
> > from Amidon, and the standard single coil, you'll get the same
> > performance. There is no magic at all in the use of "twin coils". If
> > anything, it appeared the technician on the factory production line
> > could more easily and quickly adjust the antenna for the proper tuning
> > range, compared to a single coil--perhaps that's the main reason why the
> > "twin coil" continues to be made.
> > 73,
> > Steve AA7U