Yaesu VX-7R very quiet on air band

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AgentCOPP1

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I bought my Yaesu VX-7R not too long ago mainly because I wanted an upgrade from my trusty Baofeng radio, but I also wanted it for its wide-band receive, chiefly the air band. I'll be going to the Oshkosh airshow in just a few days and I'll be listening to the tower with this radio which will be interesting. However, I've noticed that when I listen to my home airport, the audio on the radio is sometimes very quiet, even at full volume. Some airplanes I can hear just fine, but others are extremely quiet and very hard to understand. Has anyone else run into this problem? Is there a way to fix it?

I'll be asking this on the Yahoo Group as well, so don't recommend me do it because I already am ;)
 

majoco

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My VX-2 is the same - good on FM transmissions, but AM is quiet. OK when I up the volume but definitely quieter.
 

AgentCOPP1

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My Yaesu FT60R is that way. An air band antenna may help. Scanner Master has a nice one. You also may need a BNC adapter.

W-901 Airband Portable Antenna
Well I've got the Diamond SRH320A antenna which is supposed to work excellent on the air band. It's not that I have a problem receiving the signal, it's just that it's always very quiet when I hear it.
 

canav844

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VHF Air band is AM, All other things being equal, AM signals close by will be louder than ones further away, so an Air band antenna, or an antenna that performs better than the stock duck on the airband, will improve things, but likely won't solve the problem entirely.

Remember the airband is designed to work largely with 5-7watt radios in the air where the line of sight is the hundreds not tens of miles. The good news is, at Oshkosh most of the activity will be somewhat near the field or directly above it, which will help, unless you're trying to pull in farther out approaches.

Before it was damaged traversing brush on a SAR activity, my Diamond SRH-C77A (Diamond SRH77CA Dual Band (2 m /70 CM) HT Antenna Product Reviews) served well for scanning the Air band on my vx-8 and the BNC version on my HT scanners; but also provided the added benefit of being tuned for the ham bands which also helped out with 2m simplex activities.
 

gewecke

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My vx6r is just as quiet with distant air traffic but quite loud once they enter a landing pattern. :)

73,
n9zas
 

N8IAA

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Well I've got the Diamond SRH320A antenna which is supposed to work excellent on the air band. It's not that I have a problem receiving the signal, it's just that it's always very quiet when I hear it.

You may want to invest in the Uniden BC125AT. Just using the RH77, it hears all my local VHF traffic, as well as, A/A refueling in my area. I believe it make monitoring the airshow a lot more enjoyable:)
HTH,
Larry
 

AgentCOPP1

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I didn't know that the envelope on AM became audibly quieter the farther you get away from the transmitting station. I didn't think that would matter to a radio.
 

kj6zd

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<p style="text-shadow:3px 3px 3px green;color:eek:live;">AM versus FM modulation</p>
I didn't know that the envelope on AM became audibly quieter the farther you get away from the transmitting station. I didn't think that would matter to a radio.
Remember what you may have learned about the two modulation types?
Frequency modulated signals do NOT change the Amplitude of the transmitted signal including the information itself. Therefore, they will always be at maximum amplitude e.g. max. power.

Amplitude modulated signals will change the amplitude in the rythm of the modulated voice. Therefore the Amplitude may be higher or lower at certain words / vocals. In other words the amplitude is moving between very low and maximum power, depending on the information that is modulated onto the carrier. Look at a SSB signal which is basically AM with surpressed carrier.
AM signal are modulated around 6 kHz (the mirophone amplifier will largely contribute to this) in Air communication this may not be enough or it is actually lower to compensate for background noise, remember they sit inside an airplane.
Thats mainly the reason why the signal appears to be a lot lower in level as an FM signal.

Cheers!
 

AK9R

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Just a reminder...This thread is about air-band reception using amateur radio handhelds, specifically the Yaesu VX-7.
 

canav844

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FWIW: The VX-8 did a great job from just outside the North 40 on Sunday, I'm suspecting the proximity of the air traffic, ,means that what's at the tower will be hear easily. I was unable to pull in the FISKE approach from the airport though. Hoping the OPs VX-7 works at least as well for him.
 
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