Can some of you out there list what type of antenna you are using to transmit on the FM band 88-108mhz. Using about 20-50 watts.
Can this antenna be used from the 88-108 without having to tune to a certain frequency?
I will mount the antenna on a 30 foot mast in back yard of my house.
What is best circular polarization-vertical pol or horizontal pol. What model antenna are you using and where to buy.
I have been searching the net and ebay and there seems to be all kinds of antennas and stories on what to use. looking to reach about 5 mile radius so a 5/8 wave omni looks best but hope you all can recommend something that has been working good for you in a radius and not directional.
As I mentioned in another thread....I am using a CP antenna (made in Singapore). It CAN be used over the entire 88-108 MHz band, but performs BEST when tuned to the transmitter frequency. An SWR bridge is cheap -- and will prove invaluable if you do a lot of antenna work!! Tuning the antenna is SIMPLE --- but somewhat TEDIOUS....it requires powering the transmitter down, moving a slider or spacer on the antenna a TINY bit, then r-tightening the connection and checking to see if the SWR went down or UP....and diong this until the SWR is at MINIMUM for your operating frequency... TRUST ME....the extra effort IS worth it!! Final amp transistors can be COSTLY!! Re: "best" polarization -- if you are in among tall buildings you may find a VERTICALLY polarized antenna works best...but it tends to be somewhat directional - ie., the majority of the transmitted signal is FORWARD, with reduced signal "off the back" of the antenna. A CP antenna (theoretically) transmits an equal-strength signal in BOTH horizontal and vertical planes. Issues such as beam-tilt and multipath will create artifacts that can degrade a CP signal, but at power below, say, 100 watts....your biggest trouble spot in getting maximum coverage will be the local terrain....Like my setup -- if you CAN'T get the antenna up high enough to clear a forest....you're going to be dealing with reduced signal coverage -- literally, ther's "no getting around it!"... To digress....the CP antenna I'm using was purchased on eBay.....it's US$350 plus shipping...yeah, it's pricey...but it's built like a tank and with a coat or 2 of clear Krylon should last a LONG time! Again....Feed it with QUALITY coax, like LM400, and COMPRESSION-FITTED connectors ("N" is close to ideal, but GOOD QUALITY PL-259s will work...) REMEMBER.....all the power in the world goes (virtually....) NOWHERE without a TOP-NOTCH ANTENNA! Happy Broadcasting!
No model #.....Just do a search on eBay for "FM Broadcast Antenna" and it should scroll up... My antenna is only about 8 feet off the ground on a pole/tripod structure.....but the whole thing is about 700' on the side of a "bluff", with favored coverage to the east-southeast-enough to hit about half my hometown and a fair chunk of the neighboring burg as well. I intentionally wanted to shield the signal to the WEST -- the area served by several broadcast stations in a fairly large city. My goal was - and IS - to service the rural area with a format NO OTHER COMMERCIAL OFF-AIR STATION is providing ('50s and pre-Beatles '60s Oldies). From what I've read....the Comet 5/8 is a very good performer....for a LOT less $$ that the Singapore CP. But, not having had any hands-on experience with it I can't say how rugged it is. If you live in an area like the Northeast United States you're going to NEED an antenna that can stand the pounding of winter storms and strong winds throughout the year.... Again....$$ spent up front for a TOP-QUALITY antenna will provide peace-of-mind down the road....
I was also thinking about the j-pole making it out of copper 1/2 tubing looks simple enough to make and most posters says it works well.
I have my 2 meter and my hf antennas on the side of the peak of my house in the back yard, gets pretty bad here in Boston winters with snow and winds. Antennas hold up pretty good both are dipoles and fiberglass. I have the swr tuner on the HF antenna 0-30mhz and works great over the years.
Do you know if they make an swr tuner for 88-108 like for the cb/ham band I have an mfj swr tuner for my ham HF radio and was wondering if one is made for the 88-108 band. I see swr meters are made but can't find a swr tuner to keep the antenna pretty well tuned.
Personally I use a Diamond Antenna SX-1000 SWR bridge....it covers from 1.8-1300 MHz over 3 "bands"....it will handle up to 100 watts of RF when running UP TO 100 MHz....then 70 watts from 100 MHz to 160 MHz...I've had this unit for nearly 20 years and it has worked flawlessly -- and it's a LOT cheaper (albeit less rugged and a bit less accurate....) than a Bird 43!! So you're in Beanttown!!! I'm about 70 miles north of you, just east of Concord, NH. My Dad and I lost several antennas over the years to winter storms -- the largest was a 3 element FULL-SIZE 15m beam (Gotham, made in FL!! Wimpy for New England, made from aluminum TV mast!!!) on a 40' mil-spec tower with a HAM-M rotor!! Never did replace it...we moved soon after the accident.... BTW....I keep the Diamond bridge in line with one of my 3 transmitters....the other 2 have built-in reflectometers that do a decent job of checking fwd/ref power.. Right now my SWR @ 91.9 MHz is ~1.3:1 -- and that's with a 5-position coaxial switch in line, also!! All cabling - even 2' jumpers - is LM400 with compression-fitted "N" connectors....
I use a homemade J-Pole antenna and it works well but they are very finicky to setup and get tuned to the frequency of choice with lowest SWR in mind and feedline radiation needing to be choked off which can become an issue if not done properly. Definitely would not recommend it to a beginner without at least a little background in making DIY antennas.
It's hard to beat a basic center fed dipole for DIY even on the FM broadcast band, but you won't get the low angle radiation you want like you would with a 5/8 wave ground plane.
If your antenna is cut/tuned to the middle of the FM broadcast band it should work okay across the band but the SWR could get high enough at the band edges to make your transmitter angry so it's always best to tune it to the specific frequency you plan on using.
When it comes to polarization I would stick to vertical simply because most car radio antennas are vertical. Horizontal pol will give you some directivity but it's usually not the best bet for a significant amount of your listeners who will be tuned in while driving around. Circular polarization is nice on paper but when it comes to reality you really need to be pushing some decent power into a circular pol antenna to get any decent distance since half of your power will be directed horizontally and the other half vertically to put it simply. That's fine if you are running serious power but for low power it's not practical unless you run multiple bays and that will get complicated quickly when you have to start phasing them properly.
If you're on the edge of your listener base like out on the skirts of your town it can help tremendously to use a directional antenna in vertical polarization and point it towards your audience.
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