High gain base station antenna recommendations?

[TomCat4680]

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

[K5PAT]

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.

[TomCat4680]

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.  

Thanks for the tips. The RG-11 was free so I guess I got what I paid for.  

[K5PAT]

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

[TomCat4680]

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

Thanks for the links.

Do you recommend a certain model though? Which one(s) do you use?

[dave]

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).

[bugalou]

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.

[Squawk 7700]

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.

[TomCat4680]

Thanks for the suggestions, I'll look into them.

[TomCat4680]

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.

[dave]

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.

[dave]

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

[TomCat4680]

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.

[datainmotion]

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

[TomCat4680]

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?

[datainmotion]

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?

[TomCat4680]

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.

[datainmotion]

I bet your Maycom works best of the three on aero though, huh?  

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

[TomCat4680]

I bet your Maycom works best of the three on aero though, huh?  

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.  

[Squawk 7700]

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

[TomCat4680]

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".

[datainmotion]

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.

[TomCat4680]

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...

[K5PAT]

Here are some good quality air-band preamps;

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

http://www.grove-ent.com/preselectorstuners.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.

[TomCat4680]

Here are some good quality air-band preamps;

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

http://www.grove-ent.com/preselectorstuners.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)?