Repeater Antenna Shopping Question

[DylanMadigan]

Well it appears the old/cheap antenna is dieing. Does this antenna look legitimate, is it worth the price, and will it out perform the old one?

To my understanding higher gain will help me as the antenna is just above the tree line and we are in a mostly flat area. I'd also imagine this would hold up better over time, but I'm still a bit new to the radio world so I figured I'd check with the experts first.

Edit: I also found this one

 

[kayn1n32008]

The one on EBay is garbage.

If it’s not going on a mountaintop that gets severe ice and snow then the DB-411 is ok. Both are light duty junk. The weak point is the exposed phasing harness. But for the price, at a site with out environmental extremes it should be ok.

 

[mmckenna]

Well it appears the old/cheap antenna is dieing.

Ah, Ed Fong and his magical antennas.

Does this antenna look legitimate, is it worth the price, and will it out perform the old one?

Yes, decent antenna. Not hobby grade stuff, but not top of the line either. For the price, it's an OK product. Commscope is a good decent brand name. This is sort of a lower tier commercial antennas, but for budget friendliness, it's a probably a good enough product for GMRS use. It's easy to spend $1500 or more on a similar but higher tier antenna. For hobby use, it's pretty good and much better than what you'll find from the ham radio shops.

DB411-B 450-470 MHz 9 dB 4-Bay Offset Base Station Antenna - Talley Inc.

450-470 MHz 9 dB 4-Bay Offset Base Station Antenna

www.talleycom.com

I've got an account with Talley and can get that antenna for $387, so shop around. The website you linked to is giving you the MRSP price. You should be able to do better.

I use Telewave folded dipoles for a number of work applications. I current have a Telewave ANT-450d sitting here in my office waiting for install. Those are a higher tier antenna, but you'll pay quite a bit more for them. This one is a single bay, and it cost about the same as the 4 bay you linked to. Better build quality, but you'll pay for it. This one is going at a remote site that often sees hurricane force winds in the winter, so the cost is worth it for the application. Can't say I could justify paying that much for hobby use, though.

To my understanding higher gain will help me as the antenna is just above the tree line and we are in a mostly flat area. I'd also imagine this would hold up better over time, but I'm still a bit new to the radio world so I figured I'd check with the experts first.

Higher gain will focus more of your power out towards the horizon. That's good for getting as much coverage as you can.
But you'll be limited by antenna height, distance to horizon, height of the antenna on the other end, etc. Doesn't matter how much antenna you throw and the problem, sooner or later, dirt gets in the way and the signal drops off. Higher is better, as it puts the distance to horizon farther out. You might find that a lower gain antenna works just as well from low levels.

 

[kayn1n32008]

...will it out perform the old one?

Absolutely it will outperform a collinear antenna.

To my understanding higher gain will help me as the antenna is just above the tree line and we are in a mostly flat area.

Antenna elevation will trump antenna gain. Higher is better, regardless of gain.

I'd also imagine this would hold up better over time

Likely it will, but it it a light duty antenna with an exposed phasing harness. It will eventually fail due to UV exposure and/or water penetration.

For the cost, it is an OK antenna. Not spectacular, but not great either.

Edit: I also found this one

Run away as fast as you can from this one.

 

[kayn1n32008]

The gain commscope is quoting is out to lunch. No way you are getting 9dBd from 4 folded dipoles.

 

[mmckenna]

Edit: I also found this one

Yeah, kill it, kill it with fire!

Don't buy random antennas off e-Bay. I've often though that I'll make a fortune in my retirement by making my own cheap antennas and selling them on line to unexpecting hobbyists. That one looks like someone hacked it together from old TV antenna parts.

Since the antenna is the most important part of your system, you need to consider it carefully. It's not uncommon for us to spend several thousand dollars on a good antenna at one of our sites. Not saying hobbyists need to do the same, but it is worth showing how important antennas are.
The antenna will make or break a radio system. The labor involved with putting it up is worth a lot, even if you do it yourself. Put up a cheap antenna and you'll be replacing it in a short time. That's wasted labor. Put up a good antenna with good cable, and you'll not be up there replacing it anytime soon. It'll cost more initially, but in the long run you'll save money, labor and risks.

 

[prcguy]

What kind of environment will the antenna live in? Tower top mounted? Roof of a house? Exposed to high winds or sheltered? Answering those questions will help determine the quality and ruggedness you might need. Other than that you indicated it will be in a mostly flat area, so the two factors that will determine range is height and gain at the horizon. Height might be cheaper than gain when looking at high end antennas.

I have two towers at my house, both with Comet GP-9 antennas. One is at the top of a 40ft tower and the other is on a 20ft horizontal section of tower at the 20ft level nestled between other antennas. I test repeaters with these antennas and there is a night and day difference in coverage between them with only 20ft height difference and whatever influence the nearby antennas have on the lower one.

I would look for an antenna with the most gain and for UHF that will be in the 10dBd range and about 20-21ft long. You would not need any downtilt at your low level. Beware of any antenna advertising 9 or 10dBd gain that is not close to 20ft long, otherwise its not. You might shop craigs list or local ham swap meets, I have picked up lots of higher end Sinclair, DB Products, Celwave and other antennas used and in great shape for cheap. You do need to take an antenna analyzer with you to check them out and/or get a guarantee from the seller, and lots of good commercial antennas are taken out of service with plenty of good life left in them.

I am hesitating recommending antennas I would use in a commercial install because of the price, but here is one that I would try if I were on a budget and a 6dBd antenna would suffice. I've heard good things about this company and the quality is said to be very good with a really cheap price. I assume you are doing GMRS but this company has models that cover amateur and other commercial freqs. Here is his 6dB 460-470 omni version: https://childsantennas.com/shop?olsPage=products/base-450&page=2

 

[DylanMadigan]

Our weather isn't usually too bad, but we do get an occasional hurricane and in the winter we can get some ice buildup (Long Island, NY). Our intent for the system in addition to general communications is to have a reliable way to communicate when phones go out, because most of us only have cell phones, and if the slightest thing happens the lines jam or if a decent storm hits the cell towers go down (they only have like an hour of backup or something. If a main power line drops, the cells don't have long).

I suppose I'll go with that Commscope for now. If it does hold up, I could always reuse it for something else in the future, like a more distant base station or backup repeater. Is there anything I can do to it to make it more resistant to the elements? On other antenna's I've heard of people coating certain spots with silicone or putting weather proofed plastic project boxes over connections and what not, and I've seen it with a couple trucks before. Ofc the best solution would be get a higher tier antenna but on a limited budget that's not much of an option.

 

[DylanMadigan]

What kind of environment will the antenna live in? Tower top mounted? Roof of a house? Exposed to high winds or sheltered? Answering those questions will help determine the quality and ruggedness you might need. Other than that you indicated it will be in a mostly flat area, so the two factors that will determine range is height and gain at the horizon. Height might be cheaper than gain when looking at high end antennas.

On top of a tower, not much wind normally but occasional hurricanes (have all been cat 1 since i think the 30s), with a bit of snow and ice but nothing usually too crazy. Last year got really cold, but was fairly dry.

It is for GMRS yes.

 

[prcguy]

In a directional pattern, yes. Omni is closer to 6dBd.

The gain commscope is quoting is out to lunch. No way you are getting 9dBd from 4 folded dipoles.

 

[prcguy]

Old DB Products dipole arrays were great and had a very long life. I've heard newer models under the Commscope brand are having problems. If you de-grease, prime and paint the antenna you will add years to its life. You can also carefully seal the coax phasing harness junctions and connections which might address some of the complaints. I would first seal the harness and its connections with a good paintable sealant, then prime with a self etching primer then paint everything with multiple coats. I've had great success with Rustoleum spray paint in "winter grey", which blends in with the sky and takes the bright aluminum shine away.

Our weather isn't usually too bad, but we do get an occasional hurricane and in the winter we can get some ice buildup (Long Island, NY). Our intent for the system in addition to general communications is to have a reliable way to communicate when phones go out, because most of us only have cell phones, and if the slightest thing happens the lines jam or if a decent storm hits the cell towers go down (they only have like an hour of backup or something. If a main power line drops, the cells don't have long).

I suppose I'll go with that Commscope for now. If it does hold up, I could always reuse it for something else in the future, like a more distant base station or backup repeater. Is there anything I can do to it to make it more resistant to the elements? On other antenna's I've heard of people coating certain spots with silicone or putting weather proofed plastic project boxes over connections and what not, and I've seen it with a couple trucks before. Ofc the best solution would be get a higher tier antenna but on a limited budget that's not much of an option.