For FM run a vertical, I get 100+ mile range using low loss coax(5/8 hardline I picked up cheap because it was an odd size nobody else wanted it) and a generic 17' antenna. Use a switch and a beam or horizontal loop to run horizontal. Or use a 2 port antenna divider and run both at once 3db down which is still way better than the 20+ db polarization loss between vert/horizontal.
Giving up 3 dB to gain 1-2 S units at long distance would seem to be a good bargain. There are commercial omni horizontals out there like these - https://sites.google.com/site/g3xbmqrp3/antennas/bigwheel Those can be easily stacked to achieve substantial gain, too. Just marry a good vertical antenna and one or more of those. Those antennas survive well here in Minnesota, your mileage may vary. The 45 degree solution also works. Yes, I know why vertical was chosen originally - we didn't really have handhelds at the time, and it's much easier to put a whip on a car than a halo. However, I've done quite a bit of mobile SSB on two meters, and the difference in range between SSB and FM is somewhat amazing, using horizontal antennas. When I lived in Silicon Valley, there was a linear translator (think SSB repeater) in the foothills of the Sierras, a couple hundred miles away. The translator was close to a high level FM repeater. We could rather easily hit the translator from a mobile, but could not even hear the FM repeater most of the time. We used a horizontal halo for SSB, and a vertical whip for FM. This might be an opportunity for hams to do some innovation.
Always been vertical, but as i understand there's a 3 db differential between vertical, and horizontal? Is the Cushcraft 13B2, that's strictly 2 meter only, and uses a hairpin, or coax gamma match? Mine is a coax gamma match. Is it cushcraft, or crushcraft? I've got two of the similar coax gamma matched antennas now, and thinking about putting one vertical, the other horizontal, or both vertical, or horizontal...many different combination possibilities.
No there is a 20+db difference BUT if you split the power via a power divider you only lose 3db using a vertical and horizontal antenna combined. Yes a 2 port divider for 2m is not cheap to buy(easy to build!) plus you need 2 antennas. Just an option for those who don't want to invest in a 2m beam and the required rotor. Use a horizontal loop at the base of a vertical and combine with the power divider. Would have to play with spacing to make sure you don't get a lot of interaction... I have never done it but it would work. A TV antenna rotor while being a pain to use and keep calibrated for direction is plenty to turn a 12 element 2m beam too. And that is really the best option. Separate antennas and a switch(or separate radios, I use a FT-7900 in the shack on FN, FT-991 on SSB/CW/digital weak signal)
Interesting discussion and everything appears factual. I spent almost my whole career as a broadcast engineer and did both FM and TV. Early on FM was horizontal only same as TV. That way you could use your TV antenna to receive FM as well. As time went by FM radios started appearing in vehicles and portable radios with whip antennas as well. Now FM was faced with the dilemma of serving both home receivers hooked up to a TV antenna and the new mobile and portable radios. That's when CP came into the picture. CP receive antennas also have decided advantages if the transmitted signal is CP. Forgive me in not remembering specifically what the advantages were but I remember only reading that they were there but in spite of that CP receive never caught on. CP never caught on with TV as well although there never was the compelling reason to use CP. Economics had a major part to play in CP or not CP. Economics plays the same role in the two way industry as well. We're in the same boat they are and maybe even more so. Many of us are fortunate to be able to have a repeater in operation using older surplus commercial equipment. My repeater is an old Micor which just keeps running and running. Now, enough of the history. Some have mentioned directional CP. Shivley and ERI (I think) offer directional CP FM broadcast antennas. They use a parasitic element with their standard CP antenna. As I recall they can get at least a 10 dB null on the tower side of the antenna. Another option is to use crossed dipoles with appropriate phasing harness. Scala makes them and I used an array of two on a translator that was shoehorned in between two other stations. There's advantages to each type of polarization but we end up living with standards set years ago. It's not unlike analog TV. We lived with NTSC color (sometimes refered to as "never the same color") when the European PAL standard was much better.
Interesting that WA1ZJL mentioned Scala. I did a stint as a test technician and assembler for Scala Div. before Kathrein made the decision to move cell panel production to Mexico and spin off Scala Gold Line products to limited contract mfg. The reason I'm chiming in here is just before the final boot out the door, I pitched to what has to be, the most talented group of antenna guys I'd ever worked with to build for amateur use. I brought to the discussion a few examples of popular antennas used by amateur repeater owners and a ARRL repeater book. Just for giggles, we dissected a few mechanically wise, (great fun and laughs around) and ran them thru the anachoic test chamber and all were in most ways, pretty sad compared to what we built for commercial applications. That idea is still alive, but it comes down to this, who wants a antenna capable of surviving 100 mph winds, operate encased in ice or pulled by it's coax from the sea for two weeks after a Gulf hurricane and upon breaking the surface, transmit. Certainly I would if I had a repeater, but I don't, so I can't say I'd buy one for $ 500 plus. What's the market?
Mobile communications require circular pattern in horizontal plane: all mobile/portable users won't care direction to the relay while most relays try to cover as far as possible in all directions. Obviously, vertical polarization is most suited for this. Stationary users may work with directional antennas at distant relays but also obviously they must be compatible in terms of polarization. So let's leave mobile FM in vertical polarization as is. Horizontal polarization is mechanically better for Yagis and most directional antennas: it is much easier isolate (I mean RF, not DC) horizontally polarized antenna from a mast. So again it is obvious that for weak signal modes, where omnidirectional patterns mostly are not welcome, the horizontal polarization is widely used. Additional benefit: local FM relays are attenuated for approx 20dB. Circular polarization is a good idea for SATs and probably EME: you may work stations regardless their angle of polarization (vertical, horizontal, diagonal) but lose 3dB. So it may be a better idea to switch two orthogonal antennas rather then combine them both to one circular. Yep. Theoretically it is possible to create as narrow FM as SSB is (with appropriate filters, not just to reduce deviation) and acheive pretty similar communication distance. But the big advantage of FM is tolerance to frequency accuracy. Wider deviation means greater tolerance. That's why FM (FM itself and FM-based digital modes) is commonly used in channelized commercial applications. And that's why deviation cannot be too narrow. BTW, in Europe we are still using 5kHz deviation and 25kHz frequency step.
