| Author |
Message |
    
Mikefromms
Advanced Member
Username: Mikefromms
Post Number: 961
Registered: 6-2003
| | Posted on Wednesday, December 27, 2006 - 9:33 pm: | 
|
Has anyone heard of these new stealth antennas? They are whipless and supposingly work like a 1/4 wave. They can be had in 144mhz through the 800-900 or more mhz. They say police and army use them with success.
Mikefromms |
Tech833
Moderator
Username: Tech833
Post Number: 1563
Registered: 8-2002
| | Posted on Thursday, December 28, 2006 - 1:42 am: |
|
I have used them. They do NOT work as well as a 1/4 wave whip. Not even close.
I used one on my Jeep for UHF and found that it gets about half the S-units of a 1/4 wave (6-inch) whip. That's a BUNCH of difference.
Where they come in handy is situations where you need to be low profile, like going into parking garages or carports that you barely clear already.
No ego, no signature line.
|
Mikefromms
Advanced Member
Username: Mikefromms
Post Number: 962
Registered: 6-2003
| | Posted on Thursday, December 28, 2006 - 5:56 pm: |
|
Well, the truth is the truth. They are expensive garbage, then. A fellow would be as well off with a HT antenna on the roof.
Thanks,
Mikefromms |
Bruce
Senior Member
Username: Bruce
Post Number: 4275
Registered: 9-2003
| | Posted on Thursday, December 28, 2006 - 6:52 pm: |
|
You want BAD ......
THROUGH THE GLASS ( anything )
avoid them ........ |
Mikefromms
Advanced Member
Username: Mikefromms
Post Number: 964
Registered: 6-2003
| | Posted on Thursday, December 28, 2006 - 10:41 pm: |
|
Amen. What a bad idea in the first place. No ground-poor signal.
mikefromms |
Jellybean
Intermediate Member
Username: Jellybean
Post Number: 112
Registered: 1-2002
| | Posted on Friday, December 29, 2006 - 4:55 am: |
|
hmmm, I ran a through the glass mount for awhile, 2m/70cm and it did very well. Several vhf/uhf antennas don't require a ground and very little ground plane. Have you ever built a 1/4 wave out of 6" of copper into a pl 239 and put the 3" radial into the ground holes on the end of a piece of coax, hand held to a ht? I've worked repeaters 40 miles away. I've always thought that was the beauty of vhf/uhf. Maybe I'm missing something?
Jerry |
Bruce
Senior Member
Username: Bruce
Post Number: 4277
Registered: 9-2003
| | Posted on Friday, December 29, 2006 - 5:48 am: |
|
Jellybean ...
I ran them then switched to a trunk mount 1/4 wave ...... night and day the trunk mount could work things on 5 watts that the through the glass could not at 40 watts.
Also ever compaired the cb ones? they are next to useless .....
As a antenna of last resort it works fine but through the glass are not worth much if you can go with any other kind even mag mounts. |
Mikefromms
Advanced Member
Username: Mikefromms
Post Number: 965
Registered: 6-2003
| | Posted on Friday, December 29, 2006 - 7:14 am: |
|
JellyBean, glad yours worked out for you. Maybe you got a really good brand. The whole idea is for everyone to find what they can use and be happy with.
Did you guys know that Wilson make a 2 meter antenna? If that guy is anything like the cb Wilsons (1000, 5000) then that would be one heck of an antenna.
Mikefromms |
Tech833
Moderator
Username: Tech833
Post Number: 1566
Registered: 8-2002
| | Posted on Friday, December 29, 2006 - 11:06 am: |
|
JBean- Did you have a through-hole roof mount on the same vehicle to compare the glass mount to? I have (like Bruce) and I can tell you, the difference is night and day. A 1/4 wave NMO roof antenna is easily 6-9 dB more efficient than the glass mount 'gain' antennas if you run the numbers. My field tests showed an even larger gap than that.
Now, I am the first to admit, a glass mount antenna is better than nothing. Some people lease their vehicles, and drilling holes is out of the question. Mag mounts are undesireable for long-term use since they will damage the vehicle finish. Trunk lip mounts don't work well on today's curvaceous vehicles. That leaves very few options, and glass mount becomes the only viable alternative to a rubber duckie on an HT inside the car.
No ego to get in the way, no lengthy signature line to bore you... Just the facts.
|
Jellybean
Intermediate Member
Username: Jellybean
Post Number: 113
Registered: 1-2002
| | Posted on Friday, December 29, 2006 - 4:51 pm: |
|
Don't get me wrong, a gain antenna is better on the roof, but I don't thnk the thru glass is that bad. I've worked the Indy repeaters from Bloomington Ind with the thru glass, not bad if you see the distance. True the roof mount is better, but then when I do that, I also run a better gain antenna. The thru glass gain, maybe 2db worked a little better than a straight 1/4 wave on top. And if you're in town around the machines, guys around here will even run the type the hook on the window from inside, basically the same effect and do well. That's what most of the guys that run work vehicles that totally forbid any type of mount in this area run. When I mean 1/4 wave that's a true single band 1/4 i.e about 6" on 70cm. BTW... my wife will NOT,  let me run any type of antenna but a thru glass, since there's no coax showing, no holes will be drilled in her car. The one I ran was a cell phone style and it was a Diamond brand. I've got several mounted on my pickup and they're magnet or drilled. The biggest thing more likely on the thru glass, especially the cheaper ones, is the cheap very lossy 1/8" coax rg316. I also have to say the two machines in the Indy area, the ICE and the Indy radio club have huge foot prints for coverage, that helps a bunch.
73
Jerry |
Tech833
Moderator
Username: Tech833
Post Number: 1567
Registered: 8-2002
| | Posted on Saturday, December 30, 2006 - 10:40 am: |
|
JBean-
A glass mount '2 dB gain' is the same as the A99 '9.9 dB gain'. In other words, made up.
Even a '2 dB gain' glass mount antenna will have at least 3 dB LESS gain than a 1/4 wave ground plane. That means an actual gain of -5.1 dBd gain. And that is BEST case scenario.
I have played with many glass mount designs and tested nearly a dozen. The loss in the coupling and tuning cannot be overcome with enough antenna gain before the whip is so long that glue won't keep it on the glass.
Talking to repeaters on UHF is not a big deal, a paperclip and a watt can do that. However, if you really want to test one VHF or UHF antenna against another, do it talking simplex to another mobile or a small base. THAT is where you will really be able to tell. Get some obstructions between the communicating antennas and see how much difference that 5.1 dB gain makes. Like we said, night and day.
Now, as far as the wife situation goes... You are on your own there, brother!!
No ego to get in the way, no lengthy signature line to bore you... Just the facts.
|
Jellybean
Intermediate Member
Username: Jellybean
Post Number: 114
Registered: 1-2002
| | Posted on Saturday, December 30, 2006 - 9:11 pm: |
|
I thought we were talking repeater work.
The original made me think it was about repeaters, sorry.
I really only do simplex on the base, not too much mobile. |
Tech833
Moderator
Username: Tech833
Post Number: 1570
Registered: 8-2002
| | Posted on Sunday, December 31, 2006 - 11:54 am: |
|
JBean-
You were the first person to mention repeaters in this thread. Maybe that is where we lost you. |
