Glass Mount UHF Antenna
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Glass Mount UHF Antenna
Can you please tell me who makes a quality glass mount antenna to transmit and receive on UHF?
And the pro's and con's of using a glass mount, I have heard good and bad?
And the pro's and con's of using a glass mount, I have heard good and bad?
Re: Glass Mount UHF Antenna
Larsen....
Scott B.
"Never argue with seven men when you are carrying a six shooter..."
"Never argue with seven men when you are carrying a six shooter..."
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Re: Glass Mount UHF Antenna
The glass through which the RF must travel acts as a capacitor, so to
compensate for this a small tuning device is provided with an adjustment
circuit inside. In most cases, though probably not all, you can get a
perfect match of near 50 ohms for the antenna's impedance. Setting
up an on-glass antenna can be a real pain but most of the time they
work okay. Follow the setup instructions and get a ground connection
if it's called for, and have a good wattmeter or SWR meter available and
you should be okay.
compensate for this a small tuning device is provided with an adjustment
circuit inside. In most cases, though probably not all, you can get a
perfect match of near 50 ohms for the antenna's impedance. Setting
up an on-glass antenna can be a real pain but most of the time they
work okay. Follow the setup instructions and get a ground connection
if it's called for, and have a good wattmeter or SWR meter available and
you should be okay.
Tom in D.C.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
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Re: Glass Mount UHF Antenna
Hey -
basically, glass mounts suck. In addition to what Tom says, you gotta be certain that you clean the glass well, that there isn't any tint in between the aerial side and the box side, and that whereever you mount it a little aught to stick up over the roofline.
Seriously, unless you have a specific reason, a NMO mount is generally the best way to go.
-Shawn
basically, glass mounts suck. In addition to what Tom says, you gotta be certain that you clean the glass well, that there isn't any tint in between the aerial side and the box side, and that whereever you mount it a little aught to stick up over the roofline.
Seriously, unless you have a specific reason, a NMO mount is generally the best way to go.
-Shawn
Re: Glass Mount UHF Antenna
My current ride has a 800MHz Larsen Glass Mount. Works like a champ. I have used them in UHF as well without any issues. Now VHF on the other hand did not work well.
If you can drill a hole, drill it. Otherwise this is not a bad way to go.
If you have the money and can deal with a narrow bandwidth set up, Sti-Co makes some great antennas that replace your OEM antenna. Not a bad way to go other than being expensive.
If you can drill a hole, drill it. Otherwise this is not a bad way to go.
If you have the money and can deal with a narrow bandwidth set up, Sti-Co makes some great antennas that replace your OEM antenna. Not a bad way to go other than being expensive.
Scott B.
"Never argue with seven men when you are carrying a six shooter..."
"Never argue with seven men when you are carrying a six shooter..."
- whls3
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Re: Glass Mount UHF Antenna
The higher the freq, the better they work. And when tuning, you are not tuning a match between the radio and antenna, you are tuning between the radio and the box on the inside of the glass. That box is a resistance matching device. With no physical connection to the mast, there can be no actual effect on the signal to the mast. At 800mhz, they work at about 80% efficiency, at VHF you'll be lucky to get 50%.
I read your other thread about the dash lights. My guess is a bad ground, either at the lip mount, or the hood to the truck. I understand the reluctance in drilling holes, In another forum, we are merciless regarding the subject(man up, grow a pair) but I'll be nice here. A solution I have used is an L bracket screwed into the fender, inside the hood. With the bracket over the fender, so it doesn't interfere with the hood. An NMO mount in the L bracket. I think Antenna Specialists makes the bracket. This set up provides a good ground, and the extra height(about 3/4" over a standard hole mount) doesn't have much effect on the ground plane.
I read your other thread about the dash lights. My guess is a bad ground, either at the lip mount, or the hood to the truck. I understand the reluctance in drilling holes, In another forum, we are merciless regarding the subject(man up, grow a pair) but I'll be nice here. A solution I have used is an L bracket screwed into the fender, inside the hood. With the bracket over the fender, so it doesn't interfere with the hood. An NMO mount in the L bracket. I think Antenna Specialists makes the bracket. This set up provides a good ground, and the extra height(about 3/4" over a standard hole mount) doesn't have much effect on the ground plane.
Einstein, when describing radio said "Wire telegraph is like a very long cat. You pull his tail in NY and he meows in LA. And radio works the same way: you send signals here, they receive them there. The only difference is that there is no cat."
Re: Glass Mount UHF Antenna
I have had a couple glass mounts and no complaints at all. My current setup has an Antenna Specialists glass mount. As far as I can tell, it performs just as well as NMO mounts I have had in other vehicles. Proper tuning is a must, and it seems you get what you pay for.
James Eslinger
York, Maine
York, Maine
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Re: Glass Mount UHF Antenna
Ive used the AS one for years. Other than a few broken whips from car washes they have been pretty good.
- whls3
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Re: Glass Mount UHF Antenna
A field strength meter will prove my point. Or a radio with an S meter and a mag mount antenna. The second would be a better test as the true test of a rig is how well it "hears".
Einstein, when describing radio said "Wire telegraph is like a very long cat. You pull his tail in NY and he meows in LA. And radio works the same way: you send signals here, they receive them there. The only difference is that there is no cat."
Re: Glass Mount UHF Antenna
I have used nmo mounts for years and believe the only way was the nmo way. That said When I had customers asking for glass mounts I tried the antenna specialist from pctell and Besides people breaking the whips going through carwashes I was really impressed with how they performed. I originally was driving a dodge pickup with a 3db gain uhf antenna a vhf qaurter wave on nmo mounts. When I bought my new car a dodge magnum I installed the antenna specialist glass mount antennas 1 vhf an 1 uhf unity gain. I noticed absolutly no difference on vhf. These antennas provide a ground plane kit that you ground to the inside of the roof then connects to the matching device box. I have done alot of significant field testing and found no difference. Uhf works just like a unity gain antenna noticed no difference in performance. I found out they make a 3db uhf antenna I might switch out to see if it performs better. These were conducted both tx and rx through long distance simplex and repeater operation. These are mount on factory tint windows not after market.
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Re: Glass Mount UHF Antenna
I use a Larson UHF & AS 800Mhz. Both work great. I have roof mounts in my other car and can't tell too much diffrence, Both systems are repeaters in town.