Batboard

Here's something to promote thought and discussion. We have all seen the little stealth UHF "whipless" antennas that Comtelco and Antenex makes. Those are all in theory, 1/4 wave antennas (0 Gain), correct?

Well how does one of those UHF 0 gain antennas perform compared to a normal UHF 6" 1/4 wave 0 gain metal whip antenns.

Say this is installed with an NMO centered on the roof of the vehicle with no other out-of-whack variables.

Thoughts??

nmfire10 wrote:Here's something to promote thought and discussion. We have all seen the little stealth UHF "whipless" antennas that Comtelco and Antenex makes. Those are all in theory, 1/4 wave antennas (0 Gain), correct?

Well how does one of those UHF 0 gain antennas perform compared to a normal UHF 6" 1/4 wave 0 gain metal whip antenns.

Say this is installed with an NMO centered on the roof of the vehicle with no other out-of-whack variables.

Thoughts??

Actually, we use those all the time for low split UHF trunking, and have found them to be very good. As for the gain, they actually produce a gain of 1, not 0. 1 is unity gain, and, in theory, should radiate sphereically. The "hockey puck" antennas seem to have an alright radiation pattern. As for the centre-roof install, they are great. We have experienced no reduction in range compared to the whips.

Cheers

We have used them without a problem on UHF, and we use them for the MDT's on 800. They work great. I haven't heard anything positive about the VHF ones though.

In the town I live, the coiled Maxrads are very popular with PD (UHF), and in the other town were I used to work we went to the little whip VHF Antennex and they worked great.

Ah, good. This is what I like to hear. We are limited to a 25 watt power output & 25 watt ERP on the mobiles for our new system so we don't need anything big for antennas. It is either going to be a 6" whip or one of these steath things.

I figure for some of the guy's personal vehicle's they would appriciate the stealth antennas over the stick. It's not like a 6" whip is long and ugly but the mere fact that it is there is not acceptable for some.

I use the Antenex UHF and 800 antennas and they perform better than a 1/4 wave in fringe areas.

The Comtelco works well, also.

The VHF Antenexes fail constantly- even after they got redesigend.

The VHF Comtelcos work "okay", but don't expect 1/4 wave performance if you cover a large area on simplex or operate far from your repeater site. The Comtelcos also have a problem with the "cup" breaking loose from the bottom plate. This is because Comtelco has yet to figure out that you can't bond plastic with hot glue.

When you need a good low profile antenna, go with the Untenna.
http://www.untenna.com

I "built" a cell antenna for my car using a cut down UHF NMO quarter wave. Works fine in town, but in the country the "regular" coiled-center antenna works better, and the elevated feed "black monster" works best of all, of course. But the thing I built is only about 3 inches high and almost not noticeable.

I never had any luck with the "flat and fat" antennas; transmit bandwidth was too narrow for my needs. I have an Antenex TRAB1440 sitting here on the desk (140-150 mHz) which I'll sell for $25 plus UPS to anyone who is interested in it.

Tom, W2NJS
...in D.C.

maxrad has some wideband whipless models out. Any thoughts on those for UHF and 800?

The Maxrad MLPV450 is without a doubt the best of all the whipless salt shaker antenna's. I have been using it for about 3 months now and it well outperforms the Antennex and Comtelco's hands down, it performs like the 3.5 db Motorola (Phelps Dodgs for you old guys) antenna probably the best UHF antenna ever made.

I have put it on my HP 8753c Network Any and found it to be true across the 450-512 range, without spikes.

I have to give Maxrad credit for this one.

I know it works, I talk car to car with Stan, up to 30 miles.

The Antenex "Phantom" series ARE all 3db gain except for the VHF Highband and 220 MHz models. We use a lot of the UHFs and have great success with them.

http://www.antenex.com/

Wes

Well, unfortunately, we are limited to a 25 watt ERP on the mobiles. In theory, using one of these, we would need to tune the power output of the radio to about 12 watts?

I know its an 'old' thread.... but I wanted to revive it again to see what people were thinking now that some time has past... I love the idea and look of the Maxrad MLPV series like Stan was saying.. due to the size.. anything else come up these days ?

I am in Atlanta and north metro area a lot and have both city and 'rual' driving and looking for the best performer.

It's probably not such a bad idea to revive an old thread when the engineering and product information about
the original subject has changed substantially. By that I mean that Comtelco's 2543 UHF "puck" antenna has a gain of
3db and I'm using two of them with great results. Don't ask me how they do it but I'll take their word for it. The unit
is available in white or black and you get to specify your exact bandwidth when you order directly from Comtelco.


http://www.comtelcoantennas.com/PDF%20D ... /A2543.pdf

I'm using that Comtelco antenna on the back of my 2009 CVPI, and it works excellent !

Here it is on the trunk;



Uploaded with ImageShack.us

I've made dual band UHF / 800M antennas out of 12oz pop cans and a Larsen whip base. Not exactly low profile, but the beer distributor liked them. They do not withstand tree branches or truck washes very well, but they are easy to make, and they work well. For those that prefer something a little more factory, all the salt-n-pepper shaker types I've worked with gave satisfactory performance as evidenced by all the cabs using them. Cabbies want their fares, and a radio that doesn't talk is money lost. Motor cops like them too.

Great responses so far. I know the topic is UHF, but what about low profile VHF?

My big issue is a 2008 Tahoe fits in the garage fine. I cant exactly put a decent VHF antenna on the roof and still park it in the garage. I'm NOT giving up my comfy garage because of antennas. I'd love to find something for both bands UHF/VHF that would give me decent performance.

Low profile VHF is a completely different subject and story compared to UHF. For starters look at this
thread:

http://batboard.batlabs.com/viewtopic.php?f=1&t=95937

VHF low profile usually has a much narrower bandwidth than the UHF units which can limit their usefulness.

I've had good luck with the Antenex UHF phantom elite.
http://lairdtech.thomasnet.com/item/pha ... 34|3001285