Diamond Antenna's used for repeater use

[timkilbride]

I was wondering if anyone has used any of the mono or dual band Diamond antenna's for a 2m or 440 repeater use? For a quick reference, Diamond® Antenna ~ Base Station Antennas

If so, do you like it? Any desense or any other problems to the repeater that was antenna related?

I have been using a mono and dual band for simplex/base you with no problems. Just wondering how they worked out in repeater use.

TIA
Tim

 

[fineshot1]

A lot of these are multi-section antennas and as such should never be used
for repeater service or even considered for mounting on a tower.

These amateur diamond antenna are definately not recommended for any
kind of commercial or repeater service even if they are the one section models.

Having said that I do have one in service as a repeater antenna on top of a 275
foot tower. The only reason I chose to use this brand/model was the fact that
there is almost nothing else available on the 1.2ghz amateur band. It has been
in service since june 2002 and has suffered from the common ailment that all
these types of antenna do eventually in that the soldered together elements
inside it have snapped and even though the antenna still continues to work
well on transmit the receive side suffers from the famous crackel receive noise
associated with the broken internal solder joints between elements. The ant
is a Comet GP-21(very similar to the diamond models).

If I could replace the antenna I would but I am not in a position anymore to do
so. The repeater will run until the antenna quits altogether and after that I will
retire the equipment and sell it.

PS - This kind of antenna problem also happens to many commercial models
as well, but most of them are built more robustly than there amateur counterparts.

 

[n9mxq]

I've had a Diamond X-510MA in service for almost 15 years..Although it's not used in a repeater setup (It was an Echolink Link for a while) it has held up well, and continues to serve APRS in the area. I've not suffered any of the above complaints.

That being said, I wouldn't put one up for a repeater. Invest in a good commercial antenna, have it put up by an experienced and licensed crew. The benefits will far outweigh the costs.

 

[OpSec]

Short answer: No.

Long answer: They are not commercial grade and I'll echo fineshot's comments about tower mounting. If you are going to put it on a 30 foot tower you can climb to replace it every year or two when it fails, you might be okay for a while. For a light duty hammy install at a house, maybe...but not a repeater antenna in any type of severe exposed location like a commercial tower.

I just spent an hour in a cold rain with 30 mph wind on a 250' roof yesterday replacing a feed line connector for a GP15 antenna because the bolt that holds it in place within the mounting collar fell out (was laying on roof) and let the antenna spin in the wind, ripping the N connector off the feed line. Now imagine that problem 500 feet up a tower. By the time you got done paying the tower crew to replace it, you could have bought a nice vertical or 2 bay/4 bay dipole and not touched it again for 10 or 15 years.

You get what you pay for.

 

[rfguygg]

Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A405 Safari/7534.48.3)

You also need to consider wind and ice depending on the location. That said, I'm succesfully using the Comet 440 monoband on my repeater but it's roof mounted and the machine isn't intended for emergency use. It's pretty much an IRLP gateway.

Tower crews are EXPENSIVE. If I were on a tower, I'd definitely get a DB series commercial antenna.

 

[commscanaus]

I too have experienced the bolt falling out of the base of a Diamond X-6000 tri band vertical, leaving it to spin in the mounting collar, ruining the N connection to the feedline.
Mine is only mounted at 20ft on a short mast and was up for around 8 months when I noticed the antenna had a sideways tilt when no wind was blowing.
We routinely get wind gusts up to and exceeding 60Mph in my area, due to the terrain being flat and close to the sea.

Upon pulling the antenna down, it became evident that the bolt had worked loose and fallen out.
The metal used in the antenna base and connector point is too soft and the thread in the metal is now to worn to allow the bolt to hold properly when I attempted to put it back in. It actually fell out again a few months later, even with Loctite applied.
I had to make modification to the antenna mounting collar and use a heavy duty hose clamp to secure the antenna into the mounting collar.

As stated above, the Diamond range of antennas are unsuitable for use in a heavy duty purpose such as a repeater, especially at sites where access is limited by terrain or site owner.
Diamond antennas will simply prove to be too problematic over the long term.

I have also experienced water ingress due to failure of sealing compounds used in the antenna base, mainly due to UV exposure and continual flexing of the antenna structure in the wind.

The only reason I continue to use the X-6000 is also due to lack of a commercial offering for 1.2Ghz.

Commscanaus.

 

[mobios]

Depends on the application

I have some experience in using some of the smaller Diamond antennas in repeater service. When I lived in Utah we had a mountaintop site where we used a Diamond X-50 for an amateur repeater. The site itself was at approximately 9500 feet, so the "tower" was only a section or two high, which meant that we didn't need to hire tower climbers to install or service the antennas. The relatively low profile (and single section) of the X-50 worked well in the harsh environment of wind/snow, and the low cost meant that you could replace one every year or two if you had to. We found these antennas to perform very well in this application. The power limitation wasn't an issue for us since this was a low-power solar-only site.

Good luck,

Scott