Re: Air Band Receivers


kevin asato
 

Airband is what aircraft of all types - commercial, non-commercial, fixed wing, helicopter/rotor, military - use to communicate with each other and local air traffic control facilities. The VHF airband for voice is 118Mhz to 136MHz with 25KHz separation in the US/Canada and 8.33KHz in Europe. This is what is labelled airband on most radios and most commonly listened to especially if you reside below common airlanes or near airports. Although residing above the FM Broadcast band, the signals are often harder to hear as aviation band radios are much lower in power (< 100W) than FM band transmitters (xKW or xMW) and require more sensitivity to hear. This is a bit harder to do as you can then suffer overload effects from the  FM band.
In the Los Angeles area, i can hear at a range of 15-20 miles when helicopters are up at about 1000 feet on 123.025. However, the local ground utility frequency of 122.950KHz is rarely heard and i am above a local municipal airport about 3 miles away. This through use of a scanner or amateur 2 meter radio tuned to the aviation band.

There is a separate set of HF SSB frequencies used by aircraft for overwater transit. These can be picked up by receivers having SWL coverage and SSB/BFO feature. These are harder to "intercept" as they are propagation dependent but have the capability of being heard worldwide.
73,
kevin
kc6pob

On Sun, Jul 18, 2021 at 7:18 PM Frank Standford <dxer2k1@...> wrote:
I know nothing about air band, is this what the planes use? Is that covered by this group at all?
 
 
Sent: Thursday, July 15, 2021 at 1:28 AM
From: "DX Pedro" <pmm.andrade@...>
To: main@ultralightdx.groups.io
Subject: Re: [UltralightDX] Air Band Receivers
Just a correction from my part: I was confusing this with the 737 that's already available. This seems a very decent pocket rocket. It can even take an external antenna via a 3.5mm jack. I'm gonna have my eyes open when this is widely available. or is it already available?
 
// pedro andrade
 
On Wed, Jul 14, 2021 at 12:28 PM Michael Schuster <schuster.ma@...> wrote:

[Edited Message Follows]
[Reason: Quoted font too small!]

On Wed, Jun 16, 2021 at 05:46 PM, Paul Blundell wrote:
Thanks for that. I will looking at ordering soon.
 
On Thu, 17 Jun 2021, 06:43 Michael Schuster, <schuster.ma@...> wrote:
The Shenzhen Hanrongda HRD-747 is now spotted in the wholesale supply channel at US$53, minimum order 2 pieces.

https://www.alibaba.com/product-detail/HRD-747-Portable-All-Band-Mini_1600253429230.html
First comments I've seen on a production unit show lots of issues.

See the comments on this 20m/40m daytime bandscan at 

https://www.youtube.com/watch?v=S3pdeYAqlMg
 
millinchip2

 

millinchip2
1 day ago (edited)
I have had the device for 5 days now. Here is the lowdown. There are a number of software bugs causing serious issues. 1: Air band has no gain. No coverage whatsoever. It is caused I think by a setting that cannot be turned off. The setting is 2MIX. You can turn on that 2MIX setting on short wave which also disables short wave but on short wave you can reset it back to “off” by taking out the battery. No such luck with Air band. It stays on permanently with the air band. I am not sure what the setting does as it’s function or use is not mentioned in the manual. If somebody has any ideas on how to fix this or what that setting does, let me know. 2: There is no bandwidth selection on SSB. 3: There is interference that sounds like a whine on SSB when you have a florescent energy saving bulb on in the same room. Points to bad internal shielding. I thought the radio was faulty until I switched off the light and it stopped. 4: On Upper side band, voice transmission is high pitched and fine tuning does not normalise it. Lower side band is fine. Looks like I got the buggy pre-release version. Damn. If they get these issues sorted and put a bit of aluminium shielding around the main signal chips, it could be a great little radio. In fact it's still a great little radio if you don't need Air band. --It can tune in Shortwave stations with the clarity of the Tecsun PL-330. --Narrow VHF is good. -- FM Stereo is great. As good as anything out there. --Nobody broadcasts on CB here So I can't comment on CB. --Same with the weather band. --Nobody uses UHF here either. --AM is pretty good. Comparable to the Tecsun. --The speaker is a little tinny but I knew that before I bought it. -- The battery will probably last months before recharging.
 
 

 

 

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