Batboard

Hey im installing a CDM1250 in my 04 ford explorer. I have been looking for a antenna but i want something low profile. I was looking at antenex 1/4 wave but i wanted something other then a unity gain and less then 10". Is this possible and can someone let me know what to get im pretty new with this. o yeah and im not afraid to drill a hole in the roof.

to start out with, what band? low, vhf, uhf, 800, 900? your 1/4 wave will probablly be the best bet and if it is vhf or uhf you can use a 1/4 wave and a magnet mount on the center of the roof and you will still have a good ground plane. and as far as looking low profile, just paint the whip to match the vehicle. anything more than 1/4 wave will be alot bigger than what you are wanting. you will probablly be doing pretty good anyway with a 1/4 wave if it's on top center of a truck, that's more height than any car.

I'm guessing that, since he indicated the quarterwave was too long and he wanted <10", he's on VHF.

There's no such thing as a free lunch. You can't have gain AND small physical size, especially on a longer wavelength like VHF. If you don't want something that's multiple feet tall, you can forget gain altogether. One of the "can" antennas (transit type) will net you less than unity gain and an extremely narrow bandwidth. THat's about all that's truly small out there.

My advice is to suck it up and make do with a 17" quarterwave, like the RadiallLarsen NMOWBQB.

Yes sorry im on VHF mostly in the 154.xxxx range on simplex channels. A buddy of mine has a antenex VHF 1/4 thats only about 6 inches but now im starting to wonder if his installer used a UHF antenna. So are the can antennas really not worth it? I would like to keep it as low profile as i can, im a firefighter and all my warning lights and such are hidden but i also don't want to waste a perfectly good cdm1250 by using the wrong antenna. Im better this with lights and sirens then radios so if you could suggest a antenna that way i can just check it out and order it. Thanks guys

The cans are OK if you have an antenna analyzer and can tune them to the ~500KHz of VHF spectrum you intend to use.

If your buddy's antenna is not a can - just a typical wire spike - then yes, they probably used a UHF antenna and should be summarily shot.

No one's going to notice a nice black antenna on the roof, or, if they do, they won't even think about it. RadiallLarsen NMOWBQB - check it out at http://www.tessco.com. If you need someone to order one for you, PM me.

We have installed some Antenex phantom elete low profile antennas on an explorer. They are low profile and look like a short fat shark fin. Good SWR with a CDM pumpin 42.5w

http://www.antenex.com/index051206.htm

MSRP $75

definately tell your buddy that he has the wrong antennae and he is going to burn up his radio if he keeps using it that way, that is if he hasn't already damaged it.

HLA wrote:definately tell your buddy that he has the wrong antennae and he is going to burn up his radio if he keeps using it that way, that is if he hasn't already damaged it.

i didnt see where he said his buddy had any particular type of antenna... the VHF "oil can" antennas are about the height he described.. although they are not my first choice, when properly installed they will not burn up your radio.

if hes on a 6" whip, then yea.. but we need more info to determine what his friend has

Yes he has a 6" whip antenna on his cdm1550, itsw looks like the same antenna thats on his UHF cdm1250

yep, then HLA is correct, that 6" whip has the potential to damage the PA in his VHF radio...

I cant see how his recieve hasnt been severely diminished

He was able to get ahold of a true vhf whip antenna and said that it did improve, but is there a way to have his radio checked at say a local shop to make sure it hasn't damaged that radio?

easily. Take it to the local radio shop and tell them "it had the wrong antenna on it, can you check to make sure it's not damaged?" They will probably put in on a service monitor, do a couple of tests...etc
Honestly? It's a CDM. We are not talking about an XTL or a Astro Spectra here. I would just get a used one on Ebay if it's cooked.

but that's me.

No love for the sharkfin?

Yeah, they're huge, but they're tough. They're also fairly broad-banded and will take 100 watts all day long. They blend well into an SUV's roof-line if you paint it to match the car, too (having the luggage racks in place doesn't hurt in this regard, either.) And if anyone asks, just tell them it's a hi-gain XM antenna.

motorola_otaku wrote:No love for the sharkfin?

Does HPD still use those ghey things? They may work well, but damn they're ugly... especially a few of them on the trunk of a cvpi.

tvsjr wrote:

motorola_otaku wrote:No love for the sharkfin?

Does HPD still use those ghey things? They may work well, but damn they're ugly... especially a few of them on the trunk of a cvpi.

They do, along with HFD, Aldine ISD PD, and maybe one other school district. Pasadena used them for the longest time, but they've finally started going to NMO-mounted Maxrad lo-pros.

The new ones from Antenex are pretty small and kind of look like an XM antenna

What about the 5dB low pros? They don't get a lot of reception when they aren't on a flat plain with the other radios but otherwise they work reasonably well.