ICOM antenna on a Uniden scanner

[rc1990]

Good day,

I have two Uniden scanners (BC246T and BCD396T) that I utilize to monitor local public safety comm and the local airport. The 396T is more sensitive on the VHF air band then the 246T so my questions will be pertaining to that scanner. I live 8.6 km (5.6miles) from the airport (same elevation with trees and houses in between).

With the rubber ducky antenna, I was picking up very little airport comms (tower, ground, apron,..). I got a Diamond RH77CA to improve the range of my scanner and with it, I can get more airport comms but not all and sometimes, the comms audio is very scratchy and the meter on my 396T only shows 1-2 bars.

I did extensive research on the best air band scanner antenna and the Maldol AL-500S seem to stand-out but it's discontinued. I was looking at buying a air band radio (I had my eye on the ICOM IC-A14) but you need a pilot's licence (which makes sense!) to own one.

Would it increase the strength and range of the airport's transmissions if I buy the antenna of the ICOM IC-A14, the ICOM FA-B02AR? I have a few BNC to SMA adapter.

Thanks for the help.

 

[ka3jjz]

If you're just listening in your home, a better duckie really isn't going to solve your issues. You're still going to run into the issue with the trees, houses and your own home (siding, wiring, etc.) getting in the way of a clean signal .

A far and away better bet is to get a good discone, ST2 or DPD antenna and put it up above the obstructions. A somewhat less effective, but workable solution would be to put it in your attic if you can't go outdoors.. Height is the key here.

Just my 2 cents...Mike

 

[questnz]

Second that, but for out of the house portable solution you can get Watson AIR 901 W-901 Airband Portable Antenna
Chris

 

[ko6jw_2]

The RH77CA is a quarter wave antenna for 2 meters. It's shorter than a quarter wave on aircraft frequencies. A telescoping antenna extended to 20-24 inches will be a quarter wave for 118 to 136 Mhz. The antennas that come with air band HT's are designed to be used in the air where there is line of sight to the tower. Most air band radios are low power because of this. Air band reception can be difficult where you don't have line of sight or altitude. If you want maximum range an outside antenna is the way to go. I prefer discones because I can transmit through them too, but the ST2 gets good reviews.

 

[N0IU]

I was looking at buying a air band radio (I had my eye on the ICOM IC-A14) but you need a pilot's licence (which makes sense!) to own one.

Maybe its a Canadian thing, but here in the US, I can buy an IC-A14 from any vendor without a pilot's license. I can not, however, transmit with it!

 

[rc1990]

Maybe its a Canadian thing, but here in the US, I can buy an IC-A14 from any vendor without a pilot's license. I can not, however, transmit with it!

Thanks everyone for your input. It's greatly appreciated.

N0IU, I called Durham Radio (in Ontario) to enquire about the IC-A14 and I was told by the sale rep that he can't sell the radio without seeing the buyer's pilot licence.

I assume it's a Canadian thing!

 

[navaidstech]

Not true...

At most all you need is an Aeronautical NOT Pilot's Licence.

I purchased an Icom IC-A6 from Radioworld a few years ago without any issues. Even though I am in the business and do have a licence, I was not asked to produce it.

73

 

[rc1990]

My reasoning was if I buy a speciality radio (airband radio in this case), the antenna would be tuned for the airband specifically, hence the radio's antenna may have a longer range (keeping in mind all the factors that come into play when talking about range) and the audio might be a bit clearer. It seems I was wrong to assume this.

 

[ko6jw_2]

Antenna issues

Buying an air band HT will give you better performance than your scanner, but at what cost? You are still up against the inherent problems of receiving aircraft transmissions. Land mobile radio (police, fire etc.) is based on the paradigm of using transmitters or repeaters located on high buildings or mountain tops to talk to units at ground level. They are much easier to monitor. Aircraft communications are based on the paradigm of talking to mobile units at a high altitude from ground based radios. This is the reverse of what you normally try to hear. Both use line of sight, but the with air communications, unless you are up in a plane, it's much more difficult to monitor. Control towers use relatively low wattage radios because there is no need for high power.

Back to the antenna issue. The antenna on the air band radio is tuned to the aircraft band. However, it is a short helical antenna. It's not very efficient, but it doesn't need to be. If you were using it in a small plane, you wouldn't want a full size whip getting in the way.

Antennas are like camera lenses. They have to focus (tune) and they have to gather energy - the aperture. The larger the aperture the more light comes in. Antennas are the same. You can tune a short antenna, but its size will prevent it from gathering as much signal. That's why a quarter wave whip tuned to the aircraft band will outperform a short flexible antenna. And, they only cost a few dollars.

I still suggest an outside antenna over anything you can buy for inside or portable use.

 

[rc1990]

Buying an air band HT will give you better performance than your scanner, but at what cost? You are still up against the inherent problems of receiving aircraft transmissions. Land mobile radio (police, fire etc.) is based on the paradigm of using transmitters or repeaters located on high buildings or mountain tops to talk to units at ground level. They are much easier to monitor. Aircraft communications are based on the paradigm of talking to mobile units at a high altitude from ground based radios. This is the reverse of what you normally try to hear. Both use line of sight, but the with air communications, unless you are up in a plane, it's much more difficult to monitor. Control towers use relatively low wattage radios because there is no need for high power.

Back to the antenna issue. The antenna on the air band radio is tuned to the aircraft band. However, it is a short helical antenna. It's not very efficient, but it doesn't need to be. If you were using it in a small plane, you wouldn't want a full size whip getting in the way.

Antennas are like camera lenses. They have to focus (tune) and they have to gather energy - the aperture. The larger the aperture the more light comes in. Antennas are the same. You can tune a short antenna, but its size will prevent it from gathering as much signal. That's why a quarter wave whip tuned to the aircraft band will outperform a short flexible antenna. And, they only cost a few dollars.

I still suggest an outside antenna over anything you can buy for inside or portable use.

Gottcha! Thanks for the explanations!

 

[navaidstech]

My reasoning was if I buy a speciality radio (airband radio in this case), the antenna would be tuned for the airband specifically, hence the radio's antenna may have a longer range (keeping in mind all the factors that come into play when talking about range) and the audio might be a bit clearer. It seems I was wrong to assume this.

Ralph, forget buying the radio. The rubber ducky antenna won't do you any good, even if it was tuned to the frequency band. It would be great if you were up high and talking to people on the ground and vice versa, but if you're looking to listen to ground-to-ground communications then you're better off with an outside antenna UNLESS you live close to the airport.
The rubber duckies as extremely inefficient and really meant to keep portable radios portable without introducing high SWR to the finals of the HT and essentially damaging it.

73
Alex

 

[ka3jjz]

Heck even a good old fashioned ground plane mounted in the attic would work better than some of those duckies at ground level. That very same antenna can be found on many control towers.....Mike

 

[nanZor]

The Icom FA-B02AR is actually a duck that is worth it for airband use on a handheld scanner.

One thing commonly overlooked is that it is not a wideband duck, and has a narrow bandwidth. This is EXTREMELY handy when you have a wide-open front end of a scanner.

It easily outperforms the RH-77CA when compared side to side. And, you won't be getting overloaded by nearby FM broadcasters, pagers, or other vhf public service agencies due to the Icom's narrow bandwidth.

One tip - due to it's own capacitive top loading, it does not perform well when worn next to the body, such as in a belt-holder for the radio. Also keep the tip away from other objects.

Measure the narrow-band response on an swr analyzer, and you'll see what I mean. You would be hard pressed to tell the performance difference between a standard 22" quarter wave whip and the Icom duck. However, the duck adds natural attenuation out of band, which is a good thing!

Re: the airband transmit-capable HT's. Aside from a huge increase in audio power, they aren't exactly any better than your scanner as for sensitivity - in some cases actually *less* since the assumption is that you are going to be using it on the tarmac, or in the air just above the airfield.

But back to audio - despite the increase in power comes a loss of fidelity, as they are designed to heard over the din of engine / wind noise, thus the frequency response is tailored for that environment - and works well there. At home, that frequency response can become tiring. Some models are better than others in this regard and may include adjustments, but for long-term listening, you'll find the scanner usually quite a bit better. This becomes apparent once the joy of having loud audio wears off.

Scanning such as it is, is painfully slow, and operations can be cumbersome for some.

At home, I'd MUCH rather be using a lowly Uniden BC75xlt and the Icom FA-BO2AR duck, than the A14 / A16.

Still, we are dealing with line of sight, and no antenna can make obstructions disappear. Only those within a mile or so can hear planes on the tarmac (or those with REALLY good antennas or height). The Icom duck won't cure this, but IT WILL give your scanner a fighting chance against overload / desense.

 

[sefrischling]

You do not need a pilots license to own an Airband VHF radio. I work with airlines and around aircraft/airports fairly often in a non-pilot, non-aviation role, and have an airband radio. When I am at an airport or on the ramp i often use an Airband radio with a headset to know what is going on around me. I have had it with me, plain as day, around DHS, FAA, DOT and airline officials, no one has ever blinked at me owning it or having it with me while I work.

I work in the industry both as an outsider and working directly with airlines. In both capacities I am not an employee and am not SIDA badged. Still ... no issues at all.

Oh and check out a used Icom IC-A22. They are rugged bricks, good reception, 50 channel alpha character memory and can take anything you can throw at them in nearly any weather. Also less than $100 on eBay

 

[pilotman6012]

I use the Scantenna in a ground floor apartment and have no access to put it up higher,because of other buildings,trees, rules,however it sits in the corner by the window,i can usually pick up the ATC Controllers which are about 12 miles away,so i hear the aircraft and the controllers.I am slightly up on a hill,even without it being outside and picking up aircraft 150 Miles out and at times,picking up Memphis ATC controller at Nashville Sector.