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Air Traffic Monitoring => Listener Forum => Topic started by: TomCat4680 on January 05, 2012, 07:02:25 PM

Title: High gain base station antenna recommendations?
Post by: TomCat4680 on January 05, 2012, 07:02:25 PM
I'm looking for a high gain VHF/UHF outdoor base station antenna so I can hear loud and clear both sided conversations of as many air traffic control (Tower, TRACON, and ARTCC RCAG) communications as possible with very little or no static. I'm mostly interested in the civilian band, but military would be good too. I'm even looking at 2m/70 cm ham radio antennas and can't figure out which one to buy since they have a lot of mixed reviews.

I've given up on Radio Shack base station antennas after several negative experiences, and recently put up a Diamond D-130J, and my airband RX is better but still very weak and mostly static. I have a 30' AGL outdoor chimney mount  (2 story flat roof plus 10 foot fence pole) with commercial grade RG-11. My airband capable scanners are a Pro 106, Pro 96 and Maycom AR-108. Also I'm well aware that "higher is better" (I've been listening to scanners for 13 years), but my chimney is over 100 years old and the guy who sold me the mount said with brick chimneys that old, anything over 10 feet will make them topple, so more height is NOT an option unless I were to install a new freestanding tower. (I also have 2 TV antennas on the same mount btw). Also I'm well aware of the "line of site" rule.

Per Google Maps, I'm about 15 miles from KFNT, about 45 miles from KMBS, about 65 miles from KLAN, about 75 miles from KMTC, and about 85 miles from KDTW. I'd like to be able to receive strong both sided communications from all of them and possibly more.

So which antenna should I get? Would a high gain base station antenna alone even fulfill my wishes or would I also need an airband preamp?

I'd appreciate any recommendations and tips.

Tom
Mt. Morris, MI
Title: Re: High gain base station antenna recommendations?
Post by: K5PAT on January 05, 2012, 10:53:54 PM
Tom,
    First of all, for a good gain antenna to work well, all three airports should be in the same direction from your location.  Gain antennas only supply max gain in one direction, with a beamwidth of about 30 degrees.  Unless your three stations are in line with each other, a beam antenna will not do much good; especially the ones 65 and 75 miles away.
    I am confused from your post that your antenna is on the 92nd?? floor, but you say your chimney is 30'AGL.  92 floors equates to about 750 feet high. Assuming the airport ATC transmitters are around 50' high, at 750' your line of site distance from antenna to antenna is only about 47 miles.  Hearing the two farthest airports would be marginal at best, even under the best conditions.
     
    If I were you, I would concentrate on aiming your antenna at the 15 mile station and from 750' you should receive ATC and planes on the ground pretty well.  If your antenna is on the chimney at 30-40', you should be able to receive ATC fairly well, but planes on the ground will be weak at best.
     Naturally, all of this only applies to the ground stations.  The airborne transmissions should be no trouble to receive within 100-150 miles.

     RG-11 cable is 75ohm impedance and most antennas and good quality scanners are matched to 50ohm cable, so you are going to lose several db of signal with the 75ohm cable.

     An RF preamp will also help, unless you are close to a high power FM transmitter.

Hope this helps.
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 05, 2012, 11:20:48 PM
Tom,
    First of all, for a good gain antenna to work well, all three airports should be in the same direction from your location.  Gain antennas only supply max gain in one direction, with a beamwidth of about 30 degrees.  Unless your three stations are in line with each other, a beam antenna will not do much good; especially the ones 65 and 75 miles away.
   I am confused from your post that your antenna is on the 92nd?? floor, but you say your chimney is 30'AGL.  92 floors equates to about 750 feet high. Assuming the airport ATC transmitters are around 50' high, at 750' your line of site distance from antenna to antenna is only about 47 miles.  Hearing the two farthest airports would be marginal at best, even under the best conditions.
    
    If I were you, I would concentrate on aiming your antenna at the 15 mile station and from 750' you should receive ATC and planes on the ground pretty well.  If your antenna is on the chimney at 30-40', you should be able to receive ATC fairly well, but planes on the ground will be weak at best.
     Naturally, all of this only applies to the ground stations.  The airborne transmissions should be no trouble to receive within 100-150 miles.

     RG-11 cable is 75ohm impedance and most antennas and good quality scanners are matched to 50ohm cable, so you are going to lose several db of signal with the 75ohm cable.

     An RF preamp will also help, unless you are close to a high power FM transmitter.

Hope this helps.

Typo, I meant (2 story flat roof plus 10 foot fence pole) I WISH I was on the 92nd floor, if I was I would only need a paperclip. Freudian slip I suppose.  :-D

Thanks for the tips. The RG-11 was free so I guess I got what I paid for.   :x
Title: Re: High gain base station antenna recommendations?
Post by: K5PAT on January 06, 2012, 12:30:10 AM
   Here are some sites which sell good aviation band antennas, but they are not cheap.  Search the archives in this forum for homemade Yagi antennas and you should find a few.

http://www.dpdproductions.com/page_vhf_air.html#vhfairout (http://www.dpdproductions.com/page_vhf_air.html#vhfairout) DPD even sells a combo VHF/UHF aviation antenna.
http://www.ab9il.net/aviation/airband-antenna1.html (http://www.ab9il.net/aviation/airband-antenna1.html)
http://www.arrowantennas.com/gp/gp146.html (http://www.arrowantennas.com/gp/gp146.html)
http://www.jpole-antenna.com/ (http://www.jpole-antenna.com/)
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 06, 2012, 12:56:56 AM
  Here are some sites which sell good aviation band antennas, but they are not cheap.  Search the archives in this forum for homemade Yagi antennas and you should find a few.

http://www.dpdproductions.com/page_vhf_air.html#vhfairout (http://www.dpdproductions.com/page_vhf_air.html#vhfairout) DPD even sells a combo VHF/UHF aviation antenna.
http://www.ab9il.net/aviation/airband-antenna1.html (http://www.ab9il.net/aviation/airband-antenna1.html)
http://www.arrowantennas.com/gp/gp146.html (http://www.arrowantennas.com/gp/gp146.html)
http://www.jpole-antenna.com/ (http://www.jpole-antenna.com/)

Thanks for the links. :)

Do you recommend a certain model though? Which one(s) do you use?
Title: Re: High gain base station antenna recommendations?
Post by: dave on January 07, 2012, 08:38:33 PM
We've used a lot of the Arrow Antennas GP126, and at $41 they represent great value.  The DPD antennas are nice, but fairly expensive.  I've measured the performance of many of the available antennas - as I said, the Arrow Antennas GP126 represents great value.

If you want an inexpensive Yagi, get one custom made from Arrow Antennas - and get the mounting clamp (not included in the handheld Yagi antennas they ship).
Title: Re: High gain base station antenna recommendations?
Post by: bugalou on January 08, 2012, 12:05:30 AM
We've used a lot of the Arrow Antennas GP126, and at $41 they represent great value.  The DPD antennas are nice, but fairly expensive.  I've measured the performance of many of the available antennas - as I said, the Arrow Antennas GP126 represents great value.

If you want an inexpensive Yagi, get one custom made from Arrow Antennas - and get the mounting clamp (not included in the handheld Yagi antennas they ship).


Dave suggested the Arrow Yagi setup for me and the Memphis feed and I am quite pleased with its design and performance.
Title: Re: High gain base station antenna recommendations?
Post by: Squawk 7700 on January 08, 2012, 12:19:53 AM
I use both the DPD VHF Air Vertical Outdoor Model Antenna and Arrow GP126 on my feeds. They both perform equally well. The Arrow GP126 is a great value and built well.
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 08, 2012, 12:22:07 AM
Thanks for the suggestions, I'll look into them. :)
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 09, 2012, 06:15:26 PM
Anybody got a more thorough specs sheet (gain, SWR, etc.) on the Arrow GP126? I found their website and its user's manual but they don't really tell me anything about it except the price and how to install it.
Title: Re: High gain base station antenna recommendations?
Post by: dave on January 09, 2012, 06:44:41 PM
The GP126 is a classic quarter-wave ground plane antenna.  Ideally its gain would be 5 dBi (dB over an isotropic radiator).  I don't have an antenna range so I have never measured this.

It presents an acceptable SWR across the aviation band.
Title: Re: High gain base station antenna recommendations?
Post by: dave on January 09, 2012, 06:53:05 PM
I never got a chance to reply to your original post.  For the limitations you have placed on your installation, you can forget hearing both sides of anything beyond 15-20 miles.  You will hear the airborne traffic, but nothing on the ground, including the controllers. I can look at the terrain between you and the airports beyond that distance, but you won't likely hear anything at all on the ground at those places.

VHF isn't *strictly* line of sight, but you need to have a reasonable radio horizon between you and the transmitting ground stations.  Magic doesn't happen - the laws of physics don't change just because we want a certain result.  :-)

No amount of achievable antenna gain will overcome the physical path loss you are facing on those longer paths.  Not trying to discourage you, just telling it like it is, in hopes that you won't waste time and money thinking you will achieve a certain result and then don't.

Dave
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 09, 2012, 08:40:14 PM
I never got a chance to reply to your original post.  For the limitations you have placed on your installation, you can forget hearing both sides of anything beyond 15-20 miles.  You will hear the airborne traffic, but nothing on the ground, including the controllers. I can look at the terrain between you and the airports beyond that distance, but you won't likely hear anything at all on the ground at those places.

VHF isn't *strictly* line of sight, but you need to have a reasonable radio horizon between you and the transmitting ground stations.  Magic doesn't happen - the laws of physics don't change just because we want a certain result.  :-)

No amount of achievable antenna gain will overcome the physical path loss you are facing on those longer paths.  Not trying to discourage you, just telling it like it is, in hopes that you won't waste time and money thinking you will achieve a certain result and then don't.

Dave

You make a lot of sense. Good thing I don't even have a lot of money to waste too. I'm most interested in KFNT anyway, and at least I've learned that RG-11 isn't made for scanners and I need to replace it with RG-8.
Title: Re: High gain base station antenna recommendations?
Post by: datainmotion on January 10, 2012, 01:23:12 PM
Hi Tom,

If I can pop in my .02 - the Pro-106 and Pro-96 typically get just fair reception on VHF airband. The GRE based scanners typically suffer front end overload from 108-174 MHz and must be attenuated. I use both the PSR-500 and PRO-197 and the problem gets worse on high-gain antennas.

Mike
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 10, 2012, 02:36:17 PM
Hi Tom,

If I can pop in my .02 - the Pro-106 and Pro-96 typically get just fair reception on VHF airband. The GRE based scanners typically suffer front end overload from 108-174 MHz and must be attenuated. I use both the PSR-500 and PRO-197 and the problem gets worse on high-gain antennas.

Mike

Okay well which scanner(s) do you suggest for better home base airband reception? What do you use on your ATC feeds?
Title: Re: High gain base station antenna recommendations?
Post by: datainmotion on January 10, 2012, 06:37:40 PM
I use Icom PCR-100s for all 3 feeds. I also use a Uniden BC785D and a Radio Shack Pro-2006 for aviation scanning. My Uniden BCD996T performs well on this band too. However, all of these are past end-of-life so you'd have to look to e-Bay, Craigslist or others for them.

I would stay away from modern GRE receivers as many if not all of them suffer from easily-overloaded front-ends on VHF. I would focus on non-trunking base models, but avoid the "cheapies" (under $100 new).

Does that help?
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 10, 2012, 06:42:56 PM
Well I'm going to have to respectfully disagree about the GRE scanners. My Pro 106 works pretty good in the car with my WSM-225 airband magmount (5 db gain VHF/8 db gain UHF). I never have to use the attenuator and the only time I have to turn down the squelch to keep it from breaking up is with the Ground Control freq at KFNT, for example. I didn't have any overload at KMBS or KDTW either, but I wasn't at either for more than an hour.

I'll look into your suggestions though.
Title: Re: High gain base station antenna recommendations?
Post by: datainmotion on January 10, 2012, 06:55:18 PM
I bet your Maycom works best of the three on aero though, huh?  :wink:

And please don't misunderstand me about the GREs - I like those better than any other brand for trunking...
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 10, 2012, 07:46:27 PM
I bet your Maycom works best of the three on aero though, huh?  :wink:


Yeah but it's a tiny mofo and kind of hard to hear, see the display, and program.


And please don't misunderstand me about the GREs - I like those better than any other brand for trunking...

I agree, I use them both mostly for public safety, my D-130J picks up tons of it too. :) It'd probably pick up more if I had the right cable.  :|

Title: Re: High gain base station antenna recommendations?
Post by: Squawk 7700 on January 10, 2012, 08:57:00 PM
I use mostly the Uniden 350C and 355C. Here is a snapshot:
http://flic.kr/p/9dKK25

Photo of my DPD Vertical (Painted).
http://flic.kr/p/6ZfXKZ

Ken
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 10, 2012, 09:00:31 PM
I use mostly the Uniden 350C and 355C. Here is a snapshot:
http://flic.kr/p/9dKK25

Photo of my DPD Vertical (Painted).
http://flic.kr/p/6ZfXKZ

Ken

That's a lot of scanners. I'll add those to my "list".
Title: Re: High gain base station antenna recommendations?
Post by: datainmotion on January 10, 2012, 11:58:57 PM
I use mostly the Uniden 350C and 355C. Here is a snapshot:
http://flic.kr/p/9dKK25

Nice stack!

How do you like that DPD Aero antenna? I have an Omni-X that I bought recently and have been pretty happy with it.
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 11, 2012, 09:54:10 AM
Just wondering do any of you guys use airband preamps? If so which is the best one? I've looked them up and found 15 db gain ones and 20 db gain ones. Not sure if 15 is enough for me to get 5x5 2 sided comms from KFNT and ZOB Flint RCAG or if I'd need 20...
Title: Re: High gain base station antenna recommendations?
Post by: K5PAT on January 11, 2012, 10:13:53 AM
Here are some good quality air-band preamps;

https://www.scannermaster.com/LNA_AIR_Pre_Amplifier_p/24-531043.htm (https://www.scannermaster.com/LNA_AIR_Pre_Amplifier_p/24-531043.htm)

http://www.grove-ent.com/preselectorstuners.html (http://www.grove-ent.com/preselectorstuners.html)

http://www.universal-radio.com/catalog/preamps/5654.html (http://www.universal-radio.com/catalog/preamps/5654.html)

If you use a wide band preamp you may need an air band filter in front of it to filter out FM broadcast
 and other strong signals which may overload the preamp.
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 11, 2012, 10:18:46 AM
Here are some good quality air-band preamps;

https://www.scannermaster.com/LNA_AIR_Pre_Amplifier_p/24-531043.htm (https://www.scannermaster.com/LNA_AIR_Pre_Amplifier_p/24-531043.htm)

http://www.grove-ent.com/preselectorstuners.html (http://www.grove-ent.com/preselectorstuners.html)

http://www.universal-radio.com/catalog/preamps/5654.html (http://www.universal-radio.com/catalog/preamps/5654.html)

If you use a wide band preamp you may need an air band filter in front of it to filter out FM broadcast
 and other strong signals which may overload the preamp.

Yeah like I said, I was looking at the airband only ones (not wideband, I read those are crap and plus all I want to amplify is airband anyway) on Scanner Master, that's where I got my WSM-225 (and their SR-202 Sport Synch Radio, I highly recommend it btw). I was just wondering, theoretically, if 15 db gain (i.e. WRP-125) would be enough (after I got a new outdoor antenna and new cable) or should I spring for 20 db (i.e. the LNR-Air)?
Title: Re: High gain base station antenna recommendations?
Post by: K5PAT on January 11, 2012, 11:01:19 AM
Tom,
     Just to give you a point of reference:

     At my KMSY feed I am approx. 6 miles from KMSY. The antenna is a KB9VBR J-pole mounted on a 30' push-up pole. Coax is about 70' of LMR-240 cable (mini-RG/8).  NO PREAMP.  Receiver is an old radio Shack PRO-2006.
    Ground is flat- Louisiana flat. I probably have line-of-site with the ATC antennas.
I am able to receive 98% of the ground vehicles and planes on the ground, plus 100% of ATC and planes airborne.

     With your location 15 miles from the airport, I  would concentrate on raising my antenna to maybe 50' in order to get the
most height. Height is going to be your most important element in receiving anything on the ground. All the amplification in
the world won't help if you don't have a signal to amplify.  If there are any tall buildings or hills between you and the airport, that will reduce the signals even further.

     My suggestion is to work it in stages. 
First get a good antenna (yagi, if possible), ground-plane or J-pole if yagi is not available. Put it up as high as possible and put some good coax on it.
Second, see what you can and cannot hear and if the ground signals are scratchy, but you can hear them, then try the preamp. (20 db)

Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 11, 2012, 11:30:38 AM
Tom,
     Just to give you a point of reference:

     At my KMSY feed I am approx. 6 miles from KMSY. The antenna is a KB9VBR J-pole mounted on a 30' push-up pole. Coax is about 70' of LMR-240 cable (mini-RG/8).  NO PREAMP.  Receiver is an old radio Shack PRO-2006.
    Ground is flat- Louisiana flat. I probably have line-of-site with the ATC antennas.
I am able to receive 98% of the ground vehicles and planes on the ground, plus 100% of ATC and planes airborne.

     With your location 15 miles from the airport, I  would concentrate on raising my antenna to maybe 50' in order to get the
most height. Height is going to be your most important element in receiving anything on the ground. All the amplification in
the world won't help if you don't have a signal to amplify.  If there are any tall buildings or hills between you and the airport, that will reduce the signals even further.

     My suggestion is to work it in stages.  
First get a good antenna (yagi, if possible), ground-plane or J-pole if yagi is not available. Put it up as high as possible and put some good coax on it.
Second, see what you can and cannot hear and if the ground signals are scratchy, but you can hear them, then try the preamp. (20 db)



I don't think 50' is possible unless I can talk my landlord into letting me put up a new freestanding tower. Also the only tall buildings around here are in downtown Flint which is to the south of me; which is nowhere near KFNT, which is to to the southwest of me. It's pretty flat here too. In fact they call the entire region (probably a 20-30 square mile radius) Genesee Valley. Also with my D-130J the signals already ARE "scratchy but I can hear them"; so more height probably isn't even necessary.
Title: Re: High gain base station antenna recommendations?
Post by: K5PAT on January 11, 2012, 11:45:39 AM
Tom,
    I re-read your original post and I guess I was hoping for too much out of your situation.
Since you say you are hearing ground stations weak and scratchy, I would purchase the best preamp available (20db) and try it with your present equipment.  If that improves reception, then you could try changing to better coax, LMR-400 or similar. That may give you 3-4 more db of gain.
   A Yagi antenna may be too much for your chimney pole mount, but I have seen home-made ones on this forum which are light, cheap and easily made.
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 11, 2012, 11:49:38 AM
Tom,
    I re-read your original post and I guess I was hoping for too much out of your situation.
Since you say you are hearing ground stations weak and scratchy, I would purchase the best preamp available (20db) and try it with your present equipment.  If that improves reception, then you could try changing to better coax, LMR-400 or similar. That may give you 3-4 more db of gain.
   A Yagi antenna may be too much for your chimney pole mount, but I have seen home-made ones on this forum which are light, cheap and easily made.

Well Flint Approach/Departure and Cleveland Center Flint RCAG come in weak and scratchy, Flint Tower/Ground are even weaker and scratchier. LMR-400 is equivalent to RG-8. My cable run is about 70 feet so wouldn't LMR-240 (RG-8X) be better; the manual to the Pro 106 (page 16) specifically says you should use RG-8X for runs between 50' and 100'; and plain RG-8 for 100' or more.
Title: Re: High gain base station antenna recommendations?
Post by: K5PAT on January 11, 2012, 12:25:27 PM
Tom,
    You are trying to squeeze out the maximum signal strength at your location, so the lower loss in your cable, the better.
LMR-240 is equivalent to "Mini RG/8" and has higher loss than LMR-400 or RG-8.  Be careful where you buy the RG/8. Some sources sell inferior cable.  LMR-400 is much higher quality cable and costs a little more, but may be worth the price in your situation.
     The Pro-106 manual was merely suggesting that you can "get away with" smaller cable if your length is less than 100', but if you are  seeking max performance, stay with the lower loss cable.
    I ran across this thread from a few years ago which has lots of good info from Dave on antennas.
http://www.liveatc.net/forums/listener-forum/airband-yagi-antenna-designs/ (http://www.liveatc.net/forums/listener-forum/airband-yagi-antenna-designs/)
Title: Re: High gain base station antenna recommendations?
Post by: TomCat4680 on January 11, 2012, 09:00:40 PM
Tom,
    You are trying to squeeze out the maximum signal strength at your location, so the lower loss in your cable, the better.
LMR-240 is equivalent to "Mini RG/8" and has higher loss than LMR-400 or RG-8.  Be careful where you buy the RG/8. Some sources sell inferior cable.  LMR-400 is much higher quality cable and costs a little more, but may be worth the price in your situation.
     The Pro-106 manual was merely suggesting that you can "get away with" smaller cable if your length is less than 100', but if you are  seeking max performance, stay with the lower loss cable.
    I ran across this thread from a few years ago which has lots of good info from Dave on antennas.
http://www.liveatc.net/forums/listener-forum/airband-yagi-antenna-designs/ (http://www.liveatc.net/forums/listener-forum/airband-yagi-antenna-designs/)

Thanks for the tips. I need to quit trusting Radio Shack. :-P
Title: Re: High gain base station antenna recommendations?
Post by: Squawk 7700 on January 12, 2012, 12:17:28 AM
Aside from using an efficient antenna and low loss cable, the single item that most improved reception like night and day was this filter. http://www.scannermaster.com/HPN_30118_Combined_Notch_Filter_p/24-531024.htm

My receivers are in the San Francisco Bay Area and there is heavy RF everywhere. This filter really improved my reception amazingly on the airband frequencies.

Hope we can all help out?  :-)
Title: Re: Re: High gain base station antenna recommendations?
Post by: Solent Radar on January 19, 2012, 10:52:25 AM
Newbie alert ! Hi everyone from southern UK :)

As stated, filters in the fed line can remove FM radio hash and pager interference .

I use an FM bandpass filter to remove the effects of an FM broadcast transmitter 1 mile away line of sight, and a fixed notch filter plus variable notch filter to remove 4 pager transmitters 1mile away line of sight . Both transmissions would mix together to cause de-sencing of my RX. All of the filters were placed antenna end , then fed into low noise amplifiers to boost the signal down the feeder cable.

Remember, an amplifier at the receiver end , may not work as well as if placed at the antenna end.
Title: Re: High gain base station antenna recommendations?
Post by: Casper87 on January 19, 2012, 03:45:28 PM
Mr Radar,

You seem to know your tech  :-)

Close to enough to HI to pick up both Solent & Southampton Radar clearly?

C
Title: Re: High gain base station antenna recommendations?
Post by: Solent Radar on January 20, 2012, 05:36:58 AM
No not close enough to HI :( (oops , busted ;) )

2 ways from from the following; HH, HA, DM Radar, DY Radar, plus the usual London Control feeds and and Brest Control (yet to determine transmitter location of the latter).

To clarify the filter makes used in my above post (and to avoid an off topic happening ;) ).

Par Notch filters 3 off . Various spot frequencies in the 153 MHz pager TX range.

SSE (Solid State Electronics) UK VHF Airband Band Pass filter - stops local FM Broadcast radio.

SSE (Solid State Electronics) Variable notch filter.

Title: Re: High gain base station antenna recommendations?
Post by: sstokes on April 09, 2015, 06:44:11 PM
Hi Tom,

I think I may have addressed another one of your posts similar to this topic elsewhere on this forum. However, I am going to address this topic as well. I have been scanning public safety and aircraft communications for 25 years now. I have tried many different types of antennas from many different manufacturers in that time. The absolute best airband antenna I have used and still use is the Centerfire VHF Airband Base Station Scanner Antenna. I use mine all of the time. For more specifics, you can see my personal review of the antenna I just wrote clicking the link below to my website.

I really do not know why I did not write that review sooner. I have owned my Centerfire antenna for about 15 years and the thing is still in awesome shape and works as well as the day I first installed it. I would recommend that particular antenna to anyone who is into picking up aircraft transmissions with the highest gain. I routinely pick up ground control communications at an airport more than 18 miles away! It is an awesome antenna to say the least. Again, you can read my review of it at the site listed below, if you are interested. I also provide a link on my site letting you know where to get it for the cheapest price as well.

Steve
http://howtobuyapolicescanner.com/best-performing-vhf-airband-antenna-an-antenna-i-use-frequently/ (http://howtobuyapolicescanner.com/best-performing-vhf-airband-antenna-an-antenna-i-use-frequently/)