Originally Posted by EscapeVelocity

Secondly, the because the lengths of the antennas are all equal, the middle antenna is going ot be out of phase with the other 2, thus reducing the effectiveness of the antenna further.

Im going to do some computer and physical modeling of this.

Originally Posted by IDRick

Hmmmm, interesting. My son has issues with multipath in his apartment in Boise, Idaho. He lives about 10 away from the towers (located on a mountain). This may be just the ticket. I think I'll give it a try....

Originally Posted by EscapeVelocity

Thanks for the link. I think Ill build one and check it out. I have been contemplating a 3 bay design.

My first thoughts on this. Fractaling an antenna does not fight multipath....other than by reducing the effectiveness of the antenna. It in fact can increase multipath problems as it becomes more active in multiple polarizations. (Perhaps, had I been educated in the science of antennae, I might have drawn the same conclusions. All I really know is that Grabbit Ears solved the two worst problems that I have encountered. One was extreme multipath. For 4 years I tried every indoor antenna and trick I could to get him a picture without ghosting on his analog reception. Prior to the switchover, Grabbit Ears finally got CLEAR picture with no ghosting. Since the change, he has no problem with reception using Grabbit Ears. The second is a high interference area where previously I had opted for an 8-bay CM4228 plus amplifier to get full reception. Swapping Grabbit Ears for the 4228 resulted in the same signal readings as the 4228.) Secondly, the because the lengths of the antennas are all equal, the middle antenna is going ot be out of phase with the other 2, thus reducing the effectiveness of the antenna further. The 8" Loop on the Radio Shack 1874 Budget is likely a better antenna than the GrabbitEars on UHF. (Since I have them at 44 miles out, and since they typically receive green AND yellow signals making them compare to an attic antenna [using TVFool reports]-I would expect that they outperform the 1874. Typically these reports from antenna web and tvfool are inaccurate as to the antenna needed. i.e. with the weaker digital signal, very often one needs to step up to an antenna that is one size larger than recommended. )

Ive been contemplating a 3 bay, as well. My thought is to use shorter antennas on the upper and lower parts of the 3 bay...and a longer in the middle. Perhaps 1/4 waves on top and bottom and half wave in the middle.....or 1/2 waves on teh top and bottom and 3/4 waves in the middle(which would have the side effect of increasing the bandwidth as well).

Im going to do some computer and physical modeling of this.

Originally Posted by EscapeVelocity

Yes.

Think of it this way. You have a classic 2 bay design, say the Old American Made Channel Master 4220, with 8" whiskers and 8" inter-bowtie spacing. Adding another 8" bowtie(or dipole) at the center feedpoint will be out of phase with both the upper and lower antennas...thus reducing the antennas effectiveness. This is essentially what the GrabbitEars did (except they fractilized the upper and lower antenns). (After making Grabbit Ears, I tried three bay using 7" bowties and it didn't work well. Neither did 2 bay using only fractals. That one was less effective than 2 bay bowtie.)

Im not quite sure if it works like this (how the waves set up currents and voltage in the antennas - ie if its instantaneous or travels along the length of the antenna which would effect phasing)...but using the CM 4220 as an example, making the upper and lower bowtie whiskers 4" or 1/2 wave plus the 4" to the feed point on the feedlines = 8" full wave added at the center feedpoint...so it would be in phase. However the current and from the longer element would be higher compared to the shorter elements on the top and bottom, and Im not sure how that would come together or if it would increase gain over a 2 bay. (Its likely that all other things being given...that there is bandwidth to be gained from 2 different lengths of whiskers though).