What is the best UHF antenna for a repeater.
Putting up a repeater and wanted to get feedback on (if cost was not an issue) what the best UHF 440 repeater antenna would be. I see allot of talk about the DB420, but when Andrews sold the antenna line the ham specific model (440-450 MHz) was dropped.
I also see talk about Sinclair and Celwave and the Model 455-5N specific to 440-450 Mhz. Straight fiberglass vertical or folded dipole, just wanted to get some feedback, since these antennas are between $950 and $1400, ouch.
I have looked at Diamond and other Ham specific brands, but I don't think they compete with the commercial antennas.
I suppose their are considerations about how high it will be and on what type of structure, building, tower, water tower, but just thought I'd see what kind of advise I would get, thanks
DB408 or 420 cut for 450-470 will work fine on ham band.
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I agree with Joe. Celwave sold the Stationmaster line (previously Phelps-Dodge, and previously CPC before that) to RFS, who still sells the same antennas. The 440 MHz Stationmaster or Super Stationmasters are still on the market and work well.
I wouldn't use a Diamond etc. for a repeater.
The transmission line is just as important as the antenna, especially at 440 MHz: Use hardline or Heliax, and make sure it's in good shape with properly installed connectors. Make sure whatever you clamp to is clean and free of oxidation, and hopefully so is the entire supporting structure. Towers with guy wires can be problematic (sometimes) for repeaters, as slightly oxidized or intermittant guy connections can also generate noise.
Originally Posted by WB2WIK
Every dB you gain with a superb antenna, you could potentially loose with a poorly connected/damaged/lossy heliax install. Make sure you get the good stuff
An easy place to start is play around with loss calculators: http://www.arrg.us/pages/Loss-Calc.htm
That gives you a good ballpark estimate of what you can expect from various hardlines and heliax. My suggestion would be the Heliax LDF- series from Andrew. Play around with the feedline length to see if LDF4-50 is good enough or you'd need to go to LDF5-50 or higher.
I am in the market for either Heliax or Hardline, but sticker shock for a 200' run is killing me. I was hoping I could find someone that has been through this and can suggest a source or wholesaler that can save a Ham club some money, ouch and thanks
If you need 200' to reach the antenna at 440 MHz, you'll want 7/8" hardline (or Heliax). Put out a "want" on some of the boards and you'll find some, probably surplus, at a reasonable price.
Originally Posted by NF9L
Ive had a lot of Stationmaster or competitors sticks on my tower plus the 8 bay stacked 450-70 folded dipoles for commercial band customers, UHF and hi band VHF and both work just fine on 2M and 70cm. It does take a little tweaking to the cans since there is some VSWR but a 200' run of even 7/8 on 440 will mask out most of the VSWR. My runs vary from 100-160'
Im currently using an abandoned 4 bay VHF FD on 2M FM and a 8 bay FD for 440 for contests. Sure beats the Diamond I had on the house! But I had to remote the amps and preamps since that tower is 250' from the house.
I used to run a DB420 on my 444.375 repeater in Ohio. It beat the pants off the original "ham" short fiberglass stick.
Maxrad makes a stacked aluminum dipole UHF antenna, for a lot more reasonable price, that is suitable for repeaters. It may not last 30 years like the P-D or Sinclair ones, but your club can afford it..
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Antenna performance depends on whether you want gain, directivity, top or side mounting on a tower, etc. The commercial brands you mention are good performers, and will last for many years barring lightning strikes.
I was thinking about using a Diamond X-200 for a 440 to 2 meter remote base. Great gain (in fact it worked too well, having hetrodynes -- two or more repeaters on each pair ). Over a few years the inside element rusted and necessitated some major rebuilding before re-use.
Like most everything, you gets what you pays for . . .