Amptronic GX2 versus Radio

Colin Gibson

Member
Joined
Jun 27, 2004
Messages
192
Location
Nelson New Zealand
Aircraft
Sparrow Hawk ZK RCU
Total Flight Time
142.6
I have an Amptronic GX2 in my Sparrow Hawk and have found that the altimeter drops 200 ft when I transmit on the Tower Frequency here of 129.4 If I transmit on the uncontroled air space frequency of 119.1 the GX2 does not drop the altitude. This also occurs on the ground with the engine running.
I have tried other frequencies above 120 with the same efect
I also have a transponder but it doesn't affect anything.
The radio is an XCOM 760 attatched to a ground independent dipole aerial from Mobile One which is mounted high and left rear of my cabin. I feel there is excelent separation from the other equipment.
I have E mailed Dan Banks and Amptronic in South Africa but have recieved no replies yet
Can anyone explain why the GX2 drops my altitude on the higher frequency please.
 
mine does the same but since is 20 feet belwo I just dont pay much attention to it
chuckP
 
I like that idea too Chuck as when I take my finger off the button it reads normal. It has been suggested to me that the aerial is inferior and producing RF feed-back.
I'm going to try another aerial and set it up away from the gyro to see if it does the same thing.
If it improves then I will change my ground independent to a different configuration.
Colin
 
Its RF Feedback, fix the coax, aerial and ground plane and it will probably go away. Also the GX2 is not really well shielded for RF, they have similar problems in trikes.
 
what type of fuel sender you guys are using. mine is giving me a hard time. It seems to jump when the arm is swinging. and I can not figure if is in kilo or meg ohms. I have another one but it goes from max resitance to zero. so it reads oposite.

I wonder how a capacity sender will read
 
Top