What is the best UHF antenna for a repeater.

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by NF9L, Sep 11, 2011.

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  1. NF9L

    NF9L Ham Member QRZ Page

    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
     
  2. K7JEM

    K7JEM Ham Member QRZ Page

    DB408 or 420 cut for 450-470 will work fine on ham band.
     
  3. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    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.
     
  4. AD7N

    AD7N Ham Member QRZ Page

    !!!! This

    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.
     
  5. NF9L

    NF9L Ham Member QRZ Page

    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
     
  6. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    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.
     
  7. KM1H

    KM1H Ham Member QRZ Page

    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.

    Carl
     
  8. WA8ZYT

    WA8ZYT Ham Member QRZ Page

    I used to run a DB420 on my 444.375 repeater in Ohio. It beat the pants off the original "ham" short fiberglass stick.
     
  9. K8JD

    K8JD Ham Member QRZ Page

    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..
     
  10. WA7KKP

    WA7KKP Ham Member QRZ Page

    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 . . .

    Gary WA7KKP
     
  11. WA7KKP

    WA7KKP Ham Member QRZ Page

    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 . . .

    Gary WA7KKP
     
  12. AD7N

    AD7N Ham Member QRZ Page

    I've got ~50-75 feet of LDF6-50 Heliax that came my way at nearly scrap price. The seller had acquired it after it was torn from a commercial install, and had no use for it.

    If you can find local hams with commercial connections (someone in the local Repeater Owners group or frequency allocation organization), you should be able to get some very decent commercial surplus at a fraction of the cost of "full retail".

    EDIT: Also try the Repeater Builder's mailing list:
    http://www.repeater-builder.com/rbtip/repeater-builder.html

    These guys know how to build repeaters six ways from Sunday, and there's bound to be a local on the list who can help. Best luck!
     
  13. KM1H

    KM1H Ham Member QRZ Page

    I had 2 Diamonds blow apart when on top of the mast on the 180' tower which is why the 3rd try went on the house. I wasnt about to remove the rotator, loosen the yagis (one was a 4el 40M KLM) and drop a 24' .25" wall, chrome moly mast again for a POS again.

    Carl
     
  14. AD7N

    AD7N Ham Member QRZ Page

    HUSTLER antennas run circles around Diamond antennas in the ruggedness dept. They're built from design to manufacture to handle extremely rugged situations. Need an antenna that can handle 80mph ice storms on a mountaintop, or annual monsoon rains like a champ?

    A Hustler vertical would survive a lot better than a Diamond antenna...
     
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