Base Antenna advice??

[radius2479]

Hi all - I'm new here. Here's the thing ... I have my group outfitted with a few Motorola Radius UHF mobile radios. I'm taking one of them and setting up base with it. The one i'm using for base is the Gm300 model. The freq. range IS: 406-430 (split band.). My question is what base antenna should i go with for maxium range and peformance? I'm dead-set on a omni stick so any advice would be GREATFULLY appreciated. I'm kind new to this whole thing so don't get to technical on me guys .... lol. Here is one i was thinking of purchasing ... would this be ideal?

http://www.comtelco.net/html/Show_Part_ ... Inv_ID=608

I'm looking in the price range of $200-$600. Really not an issue just as long as we keep it in that ballpark. Range is important.

Thanks and God Bless you!

[Bill_G]

That's a unity gain antenna. How low to the ground are you going to put it? It's perfect for a small area like a factory, a farm, a college campus, hospital, hotel, golf course, camp ground, etc. Put it on top of a two or three story building somewhat central to the area you want served, and you'll have about a two mile radius of good coverage no problem depending on trees, terrain, buildings, etc. But, if you want county wide coverage, you'll have to get on top of a hill or a tower, well above the tree canopy.

We need some information on what you want to accomplish, and a rough idea where you intend to mount this antenna.

[radius2479]

Hi Bill,

I guess i should of been more specific. Sorry. Anyways - I'm setting up base at my home. It is in the city. There is not too many business or tall structures around it. For the most part i'm on pretty flat landscape. Although i do live near a hillside which isn't far at all from my home. I plan on getting it (the antenna) atleast above my roof top. It is a single story house. I'd say i'd like to get it atleast 20-30ft in the air.

I hope the information i have provided will assist you in explaining for me what i should go for ...

Regards,

Jason

[Bill_G]

Well, if it's Nebraska or NoDak or Mojave Desert kind of flat with few trees in sight, you might be able to get 15 miles in all directions. But, if it's New York or Connecticut wash board kinda flat with dense mixed hardwood forests, 2 miles with a coin toss. Everything changes range.

Again, if you just want to cover your gold course, your choice of antenna is adequate. If you are trying to dispatch tow trucks, you may want to look at options.

[radius2479]

I forgot to mention the radios are 40watt transmit. The area i live in is semi-falt. Not like the desert or anything. We work with a volunteer traffic assistance program. Something simular to roadside rescue. So out communication needs are based on that. I know location and your surroundings play key factor in determining how well you get out but i was just trying to make sure if i did go with the one above that it would work with my GM300's ... Now that i think of it and without having to create another thread and aside from the question above - one of my members have a Motorola Radius M120 UHF that operates on the 450-474 mhz range. Considering my Gm300's operate in a different freq. range - how do i work around this ? Will this be a problem for me? Can his radio be tuned to the GM300's freq range?

Thanks!

[SlimBob]

No.

[Bill_G]

Jason - It sounds like you need all the simplex range you can get out of your radios. Considering the low elevation you will be mounting it at (30ft) I suggest you get the highest gain Comtelco has to offer - the BSL450XL6-A. Likewise, your mobiles should have gain antennas on their rooftops. Even the slightest amount of forested area, or changes in prevailing grade will affect your range.

However, I think the first question should be how will you get licensed to operate a 403-430 radio in the US? Or are you AU?

As for your friend, there are plenty enough used Maxtracs and GM300s on the market. He should buy one to match the band you will be operating in.

[radius2479]

So i must be licensed to use that freq. range? I was never explained this when i purchased the radios. I don't think anyone around here is in that range. I used to have a Motrola PM400 which operated in the 438-470 range and never was licensed or had a problem. I really like the GM300 and have several of them. Really nothing fancy is going to be done with them rather than just communicate with my members while they are out in the field.

Thanks!

[Pj]

Yes, as you are in the US. 403-430 is in the US Govt range. If you want to tick off the three letter agencies and the military, keep playing on it.

Other than FRS, you need a license to use the radios. Start interfearing with people and the FCC (or disgruntled people) will come looking for you.

Your equipment is not type accepted for FRS, so count that out too.

I'm not going to play kilocycle cop here, but you need to walk into a reputable radio dealer in the Columbus area and they will be able to help you out with all that stuff.

[radius2479]

I know this is kinda off bounds here but since the GM300 looks to be dust in the wind - i was wondering if i would be safe using the Kenwood TK-890 UHF Mobile? (403-430, 450-490, 480-512 MHz)

Here is the read-up ... I was thinking of getting this one for my base
http://www.theantennafarm.com/catalog/i ... ts_id=4814

AND a few of these for my mobile units ...
http://www.theantennafarm.com/catalog/i ... ts_id=3182

I assume these would all fuction correctly with one another?

Sorry for the overload of questions but just want to make sure i'm purchasing what i need to be purchasing.

Thanks!

[maxkelley_kc2spy]

None of these radios are usable for your purposes without getting a license, unfortunately. You *really*, *really* need to go to a two-way dealer. It doesn't matter what brand of radio you get, you're still going to need a license, for the most part.

[radius2479]

is it possible to get a license for the GM300's?? And how would one obtain it ...?

[Bill_G]

Ouch. Someone sold you radios in the US military band, and never explained that to you. And you've never been licensed. Hopefully it wasn't too expensive of a lesson for you.

Well, the good news is I can now tell you exactly how much range you'll get out of a GM300 base with that antenna.

No, but seriously, if you can return the radios to get your money back, do it. Otherwise, they are good for trade-in value towards new equipment on a licensed system. One with a repeater would be nice.

[Pj]

is it possible to get a license for the GM300's?? And how would one obtain it ...?

Walk down to your local radio shop and they can help you, or: http://www.fcc.gov or: http://www.radiolicensing.com/

[SlimBob]

The current rate for an FCC NAL (Notice of Apparent Liability) is $14,000 per incident.

[k2hz]

is it possible to get a license for the GM300's?? And how would one obtain it ...?

If the GM300s are 406-430 they can only be used in the US by a Federal Government agency. They can not be licensed for civilian use.