Topics

Airband Listening


Paul Blundell
 

As some ultralight radios also cover the VHF Airband, I have published a guide on this.


http://ultralightradiodxing.blogspot.com/2020/05/airband-guide-to-airband-radio-listening.html
--
Paul - Moderator
UltralightDX


Gary DeBock
 

Hi Paul,

As part of the 2015 Ultralight Radio Shootout (which is posted at  https://swling.com/blog/2015/03/gary-debocks-2015-ultralight-radio-shootout-review/
I did a thorough investigation of the Air Band capabilities of the C.Crane Skywave, which was the first Ultralight radio to feature coverage of those frequencies. The excerpt below is from that article, including a link to air band frequencies in use throughout the USA, a recording of local air traffic (from Seattle-Tacoma International Airport) and a general description of airport communication:

Other Bands

The CC Skywave really excels on two other bands– one of which is unique in the Ultralight radio class. Its Weather Band sensitivity is far superior to that of the CC Pocket and DT-400W models, and it has the same Weather Alert function and selectable time periods (4, 8 or 16 hours) as those vertical-form models. Weather Band reception which is dicey on the smaller models is usually crystal clear on the Skywave—most likely because of the dedicated DSP chip for Weather and Air Band reception in the model.

If any reader places an extremely high priority on the stable reception of Weather Band alerts during emergencies, this is definitely the Ultralight radio of choice. Not only is the whip antenna far superior to the makeshift wire antenna system of the vertical-form models, but the DSP chip-provided sensitivity is in an entirely different league.

Finally, one of the obvious attractions of the CC Skywave model is its AIR Band coverage from 118-137 MHz—unique in the Ultralight radio class. According to information from C.Crane., the Si4736 DSP chip on the digital board is used strictly for Weather and AIR Band reception—and it definitely provides excellent sensitivity on both of those bands.

To get started in listening to communication between airports and airplanes the owner’s manual instructs the user to check the internet for airport frequency listings, specifically mentioning the http://www.flightradio.com site. After checking that site (and paying a $10 fee for “lifetime membership”) I was able to download a file with airport communication frequencies for the entire USA, which is posted here.

My home town of Puyallup, WA is along the direct southerly approach route for Seattle-Tacoma International Airport—a pretty busy site with lots of air traffic. The frequency listings mentioned a SeaTac tower frequency of 119.900 MHz, which is used by the tower to receive communication from airplanes approaching the airport and requesting a runway assignment. Depending upon air traffic, the time of day and luck, the CC Skywave can receive either a lot, a little or almost no communication on this tower frequency. Since only communication from airplanes is heard, the signal strengths can vary from a thunderous level (for planes directly overhead) down to a ghostly wisp (for airplanes many miles away).

Below, you’ll find a sample MP3 of the Skywave’s reception on this 119.900 MHz SeaTac tower frequency (with communication from three airplanes within two minutes). Click here to simply download this MP3.

Audio Player
 
 

The CC Skywave has a Squelch function which will mute the background noise on the AIR band frequencies while you await voice traffic—which is engaged by pushing in the tuning control for two seconds, then rotating the control to choose your desired threshold level. This is a nice feature for those who only wish to hear the voice communication, but it does reduce the radio’s reception sensitivity somewhat. In general the Skywave’s AIR Band coverage is a major plus for those interested in airport communication, although these types of transmissions are almost always brief, businesslike, and to the point. Listeners should not expect any of the emotion and drama typical in airport disaster movies!

Gary DeBock (in Puyallup, WA, USA)



kevin asato
 

Good quick read, Paul.

Not quite ultralight as i have a desktop scanner programmed but -
Depending upon where you reside, the airbands can be tough to monitor. i am fortunate to have two commercial airports (LAX and LGB) and 3 municipal airports around me. I tend to scan the Unicom and Multicom frequencies where i mostly hear the local police (LAPD and LA Sheriff's helicopters), LA Fire, Coast Guard, and the local news helicopters (122.025, 122.050MHz) as well as small aircraft as they announce their positions and intentions under VFR rules. In addition i hear the warbirds flying in formation using the "Air CB" frequency of 123.45MHz. The airbands are a lot quieter nowadays with commercial air traffic at an all-time low. In addition to airbands, i have Marine channels 9, 13, 16, 21, 22 programmed in to monitor Los Angeles/Long Beach Port Operations and local Coast Guard activity. These frequencies are also a lot quieter given the current zombie apocalypse we are enduring.

i do have a handheld scanner that i drive around with also programmed for airband frequencies and have been screened through the terminal area with a Grundig G6 or scanner already tuned to air frequencies. in addition, i have yet to have problems carrying a radio with T/R or R/O capabilities in my frequent US travels. These are my experiences with the usual disclaimer - YMMV.

73,
kevin
kc6pob

On Wed, May 6, 2020 at 10:10 PM Paul Blundell <tanger32au@...> wrote:
As some ultralight radios also cover the VHF Airband, I have published a guide on this.


http://ultralightradiodxing.blogspot.com/2020/05/airband-guide-to-airband-radio-listening.html
--
Paul - Moderator
UltralightDX


keith beesley
 

Thanks, gentlemen, good info. 

Keith Beesley
Seattle WA

On Wednesday, May 6, 2020, 10:47:07 PM PDT, kevin asato <kc6pob@...> wrote:


Good quick read, Paul.

Not quite ultralight as i have a desktop scanner programmed but -
Depending upon where you reside, the airbands can be tough to monitor. i am fortunate to have two commercial airports (LAX and LGB) and 3 municipal airports around me. I tend to scan the Unicom and Multicom frequencies where i mostly hear the local police (LAPD and LA Sheriff's helicopters), LA Fire, Coast Guard, and the local news helicopters (122.025, 122.050MHz) as well as small aircraft as they announce their positions and intentions under VFR rules. In addition i hear the warbirds flying in formation using the "Air CB" frequency of 123.45MHz. The airbands are a lot quieter nowadays with commercial air traffic at an all-time low. In addition to airbands, i have Marine channels 9, 13, 16, 21, 22 programmed in to monitor Los Angeles/Long Beach Port Operations and local Coast Guard activity. These frequencies are also a lot quieter given the current zombie apocalypse we are enduring.

i do have a handheld scanner that i drive around with also programmed for airband frequencies and have been screened through the terminal area with a Grundig G6 or scanner already tuned to air frequencies. in addition, i have yet to have problems carrying a radio with T/R or R/O capabilities in my frequent US travels. These are my experiences with the usual disclaimer - YMMV.

73,
kevin
kc6pob

On Wed, May 6, 2020 at 10:10 PM Paul Blundell <tanger32au@...> wrote:
As some ultralight radios also cover the VHF Airband, I have published a guide on this.


http://ultralightradiodxing.blogspot.com/2020/05/airband-guide-to-airband-radio-listening.html
--
Paul - Moderator
UltralightDX


James Fields <james.v.fields@...>
 

Great writeup.  The C. Crane Skywave SSB can actually "scan" up to 10 airband frequencies in a single bank.  After programming them into the bank you press both the up and down slewing buttons simultaneously to engage the scan.  I didn't see this mentioned elsewhere but if it was and I missed it, I apologize. It's not as fast as a purpose-built scanner but it's a nice feature.  Note it does not work with any of the other bands (LW/SW/MW/FM/WX) and other radios based on the same DSP chip set do not have this feature.


On Thu, May 7, 2020 at 1:10 AM Paul Blundell <tanger32au@...> wrote:
As some ultralight radios also cover the VHF Airband, I have published a guide on this.


http://ultralightradiodxing.blogspot.com/2020/05/airband-guide-to-airband-radio-listening.html
--
Paul - Moderator
UltralightDX



--
James V. Fields
james.v.fields@...


Dave613
 

Another good source for air band frequencies is https://skyvector.com/airports, the site also has aviation charts so you can see which airports are nearby your location, the most useful are probably the World VFR and larger scale sectionals. Agree the Skywave is good for air band reception, XHDATA D-808 seems to match it for reception of marginal signals IME, sound quality is better on D-808 (bigger speaker) but does not have any scanning function (unless is is hidden/undocumented).

Dave


Rémy Friess
 

Hi everyone,

I read somewhere that channel spacing on the Airband is being changed from 25 to 8 kHz.

Anyone know if this has been implemented anywhere already.

It's likely to be a problem as many receivers tune only in 25 kHz steps.

73, Rémy.




Tom Crosbie G6PZZ
 

Rémy ,

IIRC it has already happened. There was talk of changing from 25 to 12.5 to double the number of channels but instead they went straight to 8.33kHz effectively tripling the number. The change to a long time to implement with both ground stations and aircraft. The scanners (particularly handhelds) available around the time could switch to 12.5 spacing and still pick up plenty of signals, courtesy of breakthrough due to the dreadful filtering they used to have. We did some tests when I worked for Lowe Electronics, we were right under a major air lane, Amber 1 I think.

 

Perhaps filtering has improved  in the day of the Ultralight. I don’t have one but even if I did, the skies are quite empty above me are noticeably empty.

 

HTH

 

73 Tom G6PZZ

 

From: main@UltralightDX.groups.io <main@UltralightDX.groups.io> On Behalf Of Rémy Friess
Sent: 07 May 2020 17:10
To: main@UltralightDX.groups.io
Subject: Re: [UltralightDX] Airband Listening

 

Hi everyone,

I read somewhere that channel spacing on the Airband is being changed from 25 to 8 kHz.

Anyone know if this has been implemented anywhere already.

It's likely to be a problem as many receivers tune only in 25 kHz steps.

73, Rémy.

 

 


Paul Blundell
 

Here in Australia we are still 25kHz, I believe that Europe is 8.33kHz spacing.


On Fri, 8 May 2020, 2:10 a.m. Rémy Friess, <rfriess@...> wrote:

Hi everyone,

I read somewhere that channel spacing on the Airband is being changed from 25 to 8 kHz.

Anyone know if this has been implemented anywhere already.

It's likely to be a problem as many receivers tune only in 25 kHz steps.

73, Rémy.




--
Paul - Moderator
UltralightDX


Max Italy
 

Hi, just a technical note, all the DSP portable radios use an external circuit to receive the air band, it is not received directly from the DSP IC (usually Si4735 in our radios)

The external circuit is a TA7358 receiver ic or similar (LA1185, KA22495, AN7205 or chinese versions).

This is a single chip receiver, PLL controlled in our case, with a MIX output, generally 10,7MHz.

The Si4735 is locked to receive 10.7MHz while the microprocessor controls the PLL for tuning. It's a downconversion of the band to IF

In any case i think that for the Air Band there is nothing better than a RTL dongle (SDR) because signals appear and disappear quickly and you can see them in a wide range of frequencies. With some autotuning software it is simple to receive the strongest signal on the band. 

To summarize i would say that with a SDR you receive simultaneusly all the frequencies in a band but activate the audio on one frequency. This is different from scanning in a circular way a group of frequencies.