I can vouch for the Coily Enforce Antenna. I have used the older generation enforcer and now the New Enforcer with larger coil and double tubed mast and Bird QC connector for quick swap to any other connector I want to put on the antenna.
I have run A99, Imax 2000/GPK, Maco V58/V5000, Signal Engineering Thunder 8XB, Shakepere Super Big Stick and Army Stick... and just recently....the Jay in the Mohave I-10K.
The Jay in the Mohave and the Coily Enforcer antennas (with Maco V58/V5000 following a little behind) did the best job to eliminate any types of TVI and RFI.
However, the I-10K and the Maco V5000 were close in performance, whereas the .64 Enforcer gave me better performance out in the distance and on DX. I have done some back and forth comparisons.
I tried a friends I-10K here. It was very close to the Maco V5000 that I had previously. It did do better for eliminating TVI. The Maco and I-10K were better than a Imax 2000 w/GPK. I have had two Coilys. One was the first generation Enforcer (got it last summer) and sold it to my good friend and got the newer Enforcer (built better and tuned in a little better says Mr. Coily). I had the I-10K on one side of the house at 35ft base, and the Coily Enforcer was at the other end of the house at 35ft base. Both were used with 100' LMR 400 for testing (I usually use Heliax, but I wanted to make sure everything was fair) on 27.2050 and 1:1 match @ 50 ohms impednace. I used a Alpha Delta 3 position switch box. I used a Grant XL, Galaxy 66v, Cobra 200GTL, Kenwood TS-2000X, Icom 706 MKIIG for my test radios. The wattage was left at 4 watts dead key for the single final radios, used the Cobra 200GTL at 3 watts DK swing 100watts on Low power and 40 swing 160-ish on HIGH. the ham radios were done at around 20 watts dead-key and swing forward.
I saw about 1 S-Unit gain with the Coily Enforcer on receive and transmit to the I-10K. People said on SSB (with the Grant XL and Cobra 200GTL) that my signal went from 7 s-unit peaks on the I-10K to 8-8 1/2 peaks on the Coily. The biggest jump was the modulation.
I tested the switch box back and forth for about a week straight on signals close to the noise level and signals very close. The signals close to the noise level were the ones the showed the largest improvement. I had a guy about 35 miles out (its all flat terrrain here, no hills or mountains..) that was barely copyable with the I-10K. I flipped to the Coily and the signal was now understandable. It was not a huge difference "like using a beam" but I did see a difference.
I am not in any way, shape, or form in business with Mr. Coily or trying to promote his products. I am just stating hard core facts that I found and your results may differ based on many variables (elevation, power, atomospheric conditions, etc....). I will admit that last summer I was sorta skeptical about the claims and such that I read on the Coily website, but I can now vouch for almost 1 year of use that his claims are all true. My output now (in comparison to a A99 or Imax as these are a popular reference point since so many people have them) is that now the gain of the antenna makes my signal now appear that I am running a 1 or 2 pill linear all the time, and I am completely barefoot. Also, the same goes with the receive. The white noise and static from the A99 and Imax which was ever so bothersome, it completely removed, and I now can hear distant station out 30+ miles easy now.
I feel the money spent on the coily was completely necessary, it removed all my noise at the bottom of the s-unit scale, eliminated TVI and RFI that I previously had, receives and transmits better and farther than any other stand-by groundplane I have tried, and it actually has gain to it, I figure around 6-ish DBD gain, I have done many tests and with 100 watts into the Coily it appears the ERP output is around 400-ish (giving the antenna roughly a 4x multiplication factor, or around a 2 element beam).
I have tried 100 watts (dead key or CW) into the A99 and received 1/2 the perforance. I double my power into the Coily Enforcer, I gain 1 s-unit. I double my power into my Imax, I gain about 1/2 s-unit. Everytime I quadruple my power into the enforcer I get around 2 s-units. When I quadruple my power into the Imax I get 1 s-unit. Do some calculations with the antenna gain and multiplication theory and you'll find on paper that my real world results are about correct. The more power you put into the Coily, the best it gets!
Thanks and please I do not want any arguements or such coming from my personal experiences and test results.
(P.S. If anyone wants to know why I didnt go to the Jay In the Mohave I-10K, I had troubles getting email response and was told eventually that they were backlogged and I didnt want to wait. So I then kept looking around and found the coily antennas. I didnt know about them till last summer of 2005.
Thanks very much.