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Looking for a good vhf antenna

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#2
Its a vhf marine antenna requiring a side support bracket and would be optomized for the vhf marine band. You might want to tell us what would you be using it for then we could give an appropriate opinion.
 
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#4
This antenna is not a commercial repeater grade antenna and does not have the frequency coverage for your stated vhf repeater split(your transmit and receive frequency). Chances are it would perform poorly for this function. It was made to mount and be used on a sea going vessel with a vhf marine band radio. If I were you I would choose a commercial grade antenna for the frequency range you need.
 
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#6
I am not sure what you have to mount it on or how high(tower, building top, water tank, etc.) but I would probably go with something similar to the quality of the antenna below on ebay.
That one is for illistration purposes as its not the right freq range but you get the idea from looking at it. Either similar to that or perhaps a 4 bay dipole array but that is rather large for the vhf-hi band and this will most likely cost you more than $500. Plus you will need good quality feed line such as andrew or comscope hardline or similar. Good luck & let us know how you make out....


http://cgi.ebay.com/Decibel-Product...VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247
 
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#7
Yagi's

I'm not against yagi's either, but I want to have 360 coverage, how do I over come this to get full wide covergae. Would it work with two yagi's or do I need four. How would they connect to work with each other, I'm unfamilar with yagi's (other then that I lnow their directional).
 
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#8
A 4 bay dipole array is about the best antenna for VHF hi band at 6dBD omni or 9dBD in an offset pattern and about 21ft in length. These will cover the VHF high band range with no tuning. The better brands are Cellwave, Sinclair, DB Products and cheaper brands like Cushcraft or even Maxrad will have the same performance but are built much cheaper. Used Sinclair and DB Products dipole arrays show up cheap on Ebay and the Maxrad version is not too expensive new, maybe $250. There are a few 21-23ft long fiberglass monsters from Cellwave, Telewave and others that will have upwards of 5.25dB gain with the band width you need but there close to $1k new and I don't see too many of these used. The ham brand antennas like Comet, Diamond Hustler and dozens others will claim wild gain figures and you get what you pay for. Make sure the gain figures are referenced to a dipole (dBD) and you can compare apples to apples, but some hamster brands use the dBD rating and still lie. If you see some miracle VHF antenna thats 8ft long and claims 11dBD gain, something stinks. A repeater is only as good as the antenna you connect it to so my advice is not to skimp on the antenna. Stay with the brands that commercial repeater operators use and you will not have to worry about the antenna again for many years.
prcguy
RADIOGUY2002 said:
Okay, what do you suggest. I open to just about anything up to 500.00 to have it done right.
 
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#9
What about one of these?

YDA1504 Dipole Array Antenna UHF Base, Frequency: 150-174MHz, Center Freq: Tunable, Omni Gain: 6dB, Offset Gain: 9dB, Dipole Bays: 4.

Made by antenex, any opionion on this?

I need somthing for the long haul, thats price effective and will not have me up on the roof every year. And yes I would like my repeater to be truily effective. I spent the money for lmr-400 cable you better believe I want the best antenna with in some constraints. My budget is limted thow, on certain antennas and I have read bad or mixed reviews on onmi directional vertical antennas.
 
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#10
Info

Thanks guys, I appericate the info. Pls, keep me informed. Its my first repeater project and I like to do it right. My j-pole is effective, but I feel that the system could be way more effective. Whats the best way to mount this with out a tower? Would a mast system work?
 

SAR923

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#11
I don't think you're going to get a better antenna that a stacked dipole array in terms of durability and performance. You're going to have to tune it for good performance on your input frequency but the coverage should still be broad enough to RX well. I know almost nothing abut antennas but our comm techs swore by Sinclair stacked arrays for repeater sites. We had a 110 mph wind storm one winter off the Pacific that took down an entire tower with all kinds of government and cellular antennas and the Sinclairs were the only ones that were still usable when they put up the new tower.
 
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#12
The Antenex is probably fine for your application, I have the Maxrad version thats nearly identical and its good for non mountain top use. I have a few DD Products and a Sinclair and they will outlast the Antenex or Maxrad types probably 10X overthe cheaper brands with their sealed coax connections and silicone grease flooded coax. The actual performance and gain will be the same. You will have to weatherproof the connectors on he phasing harness and the connectors on the dipoles, this is the real weak spot on the cheaper dipole arrays, There is an aluminum SO-239 on the dipole and if water gets in the female connector corrodes prematurely. You can use Pentrox or other anti corrosion electrical connection grease on the connectors and wrap them with with a layer of Scotch 33+ tape then some heavy duty weather wrap like supplied with Andrew Heliax connectors. The first layer of tape keeps the gooey outer layers from sticking to the connectors and ruining them.
prcguy
RADIOGUY2002 said:
YDA1504 Dipole Array Antenna UHF Base, F: 150-174MHz, Center Freq: Tunable, Omni Gain: 6dB, Offset Gain: 9dB, Dipole Bays: 4.

Made by antenex, any opionion on this?

I need somthing for the long haul, thats price effective and will not have me up on the roof every year. And yes I would like my repeater to be truily effective. I spent the money for lmr-400 cable you better believe I want the best antenna with in some constraints. My budget is limted thow, on certain antennas and I have read bad or mixed reviews on onmi directional vertical antennas.
 
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#13
Update

Any opionions on this one Andrew Corporation DB222, anybody have experience with this. Here's what I was thinking, 23 ft roof top with a 10 ft mast attached to a chimmey with the antenna attched to it. So, it will be approx 43 ft in the air. With LMR-400 cable run of 33 ft into a lighting arrestor with a 10 foot jumper able.

Any other input or ideas.....
 

Thayne

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#14
The DB222 would be excellent, Lists for $328, so you should be able to get it cheaper than that or maybe find a used one.
 
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