VXA-300 and antenna for airband monitoring

[kbantikos]

Gentlemen help me out on this, i watch this forum quite a long as a guest but now i need your help. i purchased the vxa-300 for monitoring the airband but i am little dissapointed cause although in the papers has a good sensitivity it does not work as i thought so. Imagine that my yaesu vx-5 is more sensitive in airband than my vx-300 and this is sooo dissapointing, anyway i live 4 to 5 km from the athens international airport in a rather high area. Here we go
1) i am intrested in listening only the vhf airband (118-137) what rooftop antenna should i use with my vxa-300?
2) in my work (not so high area) if i use an antenna like rh-771 (europe rh77ca) or maldor al-500h (although this antenna seems to be totally dissapeared) will i see drastic changes in reception or it is not worth it?
3) if i use an antenna (in my work or at home) like SkyScan Desktop Discone Antenna will i see major diffrences ( i have seen in tests that this antenna goes quite well in airband) or it does not worth it?
i am not intrested in creating an antenna in my own only buying.
waiting your replies and pls set in mind that i live in europe and i want to listen a lot an if it was possible as high and as long as i can with my vxa-300.

 

[nanZor]

... i purchased the vxa-300 for monitoring the airband but i am little dissapointed cause although in the papers has a good sensitivity it does not work as i thought so. Imagine that my yaesu vx-5 is more sensitive in airband than my vx-300...

Don't be surprised as these are not really designed for super-high sensitivity, although they are good. As a pilot, you mainly use them to communicate with your Local airport either on the tarmac or in the pattern, typically as a backup, or perhaps your main radio in an experimental, etc. So lack of super high sensitivity is not a major drawback and can actually be a plus in an rf-swamped condition if you are a pilot. But the 300 is not a dog either.

Check that you aren't getting fooled by an apparent lack of sensitivity by experimenting with the audio tailoring. For example, you may like the MD2 tone setting.

Also, since you are just monitoring, MAKE SURE you have the PTT function DISABLED. Please.

I can't guide you much on the external antenna, other than saying that you may notice some improved performance with a longer whip, as opposed to the oem duck that comes with it. It will be an improvement, but it won't be earth shattering. I have a Maldol, and it improves it some, but I don't normally use the 300 for monitoring casually, I only use it while airborne.

A REAL discone outdoors might do well, but that desktop version - not so much. And as with all handhelds, they aren't REALLY designed for large-scale antenna arrays anyway. Yes, you can do it and hope for the best, but don't be surprised if you suffer desense / overload, even on a single-band radio.

Quite frankly, my 300 stays in my flight-bag, with PTT DISABLED, and use higher-sensitivity / feature-laden scanner for listening while at home.

 

[kbantikos]

First of all Ty so much for your answer.

example, you may like the MD2 tone setting.

Thats exactly what I like.

MAKE SURE you have the PTT function DISABLED

If I had not I would have been transmitting in one of the largest airports in Europe lol.

But the 300 is not a dog either.

By the way what is according your opinion a real dog (scanner,transreceiver,mobile,base, or whatever) machine?

Imagine that I had long ago a yaesu ft-8100 with a rooftop antenna can't remember the brand now and I was listening even the clearance delivery service all the ground movement and so on. I want badly to listen to all of these again.

 

[nanZor]

By the way what is according your opinion a real dog (scanner,transreceiver,mobile,base, or whatever) machine?

For the serious airband listener, any scanner that is dual-conversion with a 10.7 or thereabout 1st IF. Not even worth considering unless you are out in the sticks.

A really-bad combination is the airband Yaesu/Vertex VXA-710 Spirit handheld attached to a discone. This multi-service dream-machine does not have the front-end bandpass filtering to handle all of those services well especially when attached to a discone!

Imagine that I had long ago a yaesu ft-8100 with a rooftop antenna can't remember the brand now and I was listening even the clearance delivery service all the ground movement and so on. I want badly to listen to all of these again.

You may want to duplicate that setup - however I can vouch for the 2M-only Icom-2200H as a better receiver than the 8100 for airband. I was amazed that it did AM airband, (rx only) and it sounded soooo good. The front-end held up well attached to a discone, even though that part of the receiver is not in the guaranteed specs. Also take a look at the newer IC-2300, although I can't verify that it does AM even if the coverage is the same as its older sibling. While these radio are also double-conversion, they have better front-ends than the typical scanner.

The key element is obviously a good antenna, and a receiver front-end that can handle it. Most scanners don't have serious airband bandpass filtering, so I can recommend something like the AOR ABF-128 bandpass filters. They are convenient for attaching to handhelds or inline with your new antenna. I notice that Waters and Stanton have two versions - BNC and now an SMA version! Great for attaching to handhelds. It is what I would use if I had an outdoor antenna attached to the VXA300 for example and wanted to be sure I wasn't getting overload / desense from outside the airband passband.

Being 4-5 km away from the airport, can still mean you need a good outdoor antenna - or if indoors or on a deck, I'd recommend a purposely-built vhf airband antenna. I see a lot of multi-band antennas touting "airband" as a selling point, when in reality they are not resonant there - but the manufacturers won't get sued because yes, they will receive anything just like a paperclip will.

Are you up for homebrewing or do you want to stick to a pre-built antenna?

 

[nanZor]

Thinking about it a little more...

You have decent-enough radios to test out any new antenna. However, a bandpass filter will help validate that the radios are performing as best they can when attached to it - it may not be needed at all, but at least you'll know within reason. I'd concentrate on the antenna setup first.

My preference whether commercial or homebrew, is to use antennas specifically designed for the band. Someday, since I also do milair monitoring, I'd like to have a Diamond D-777. Or, something nifty from DPD:

http://www.dpdproductions.com/page_vhf_air.html

The Waters and Stanton WBA-20 looks interesting and might even be do-able indoors with only 2 opposing radials for tight spots.

Since they are specifically made for airband, I can somewhat assume I've done my best. In the interim, amateur 2M antennas do ok, but I want to do better. I also have fun building my own airband dipoles, folded dipoles, J-poles etc. Might save some cash for sure.

 

[nanZor]

Quick note about the 2200H - my unit operated with 25 khz steps in airband, but I'm not sure if it covered 8.33khz steps. I no longer have the radio so I can't verify it - while I loved the receiver, I needed more features so it was sold to an amateur who really needed it. I'm not sure if your area uses 8.33khz steps, and not sure if there is a European version of the 2200h that does so. Just wanted to put this out as something to check if getting something like this crossed your mind..

Still, I'd put money into an antenna first...

 

[kbantikos]

Thank you for all of your answers they were really helpful regarding my issue, i will trust your advice and buy the IC-2200H cause as i can see the icom 2300 does not have airband frqs. i am intrested only for commercial antennas not building my own. As for the 8.33 spacing its not in use here in Greece. My purchase of vxa - 300 was a total failure. As for the antenna i see that it will be a difficult task to choose

 

[nanZor]

A pilot would love the vxa300 - check into your local pilot's shop if you should want to sell it.

Note that unless you mount the 2200h down to a surface, you'll be pushing it around on the desk with the somewhat stiff buttons. You'll probably end up using the microphone keypad for operations mostly.

Be gentle with the volume and squelch knobs. On all the units I've come across, they may appear to be a LITTLE wiggly. Don't man-handle them. And note that when you rotate the squelch beyond 12 oclock or so, the attenuator also kicks in.

Also a surprise was that the wide/narrow option even works on airband! Be sure to try both to see which you like. I wasn't sure if it was actually changing the rf-bandwidth, or was an audio tailoring, but either way sounds sweet.

As for antennas - start with your typical 2M amateur antenna and see how it goes from there!