I am getting a strange tone in my comm. radio on one frequency. I have a Terra TX 760D.
The problem has at least two possible clues.
First for several years I have intermittantly gotten a dual tone when coming into my home area monitoring 123.0, It is kind of an EE-AH sound resembling a donkey. (now stop laughing) It is on a maybe 60 second interval and a very strong signal. I had a guy with some radio monitoring equipment try to hear it a couple of hours after landing one day and we could not find it.
Next clue. I just got an APRS tracker, Micro-Trak RTG. When this unit transmits on 144.35, I get a similar tone. It is different in pitch and not quite as noticeable a difference in front and back as the other tone but still very similar. I can tune .02 up or down and the APRS tone is gone.
This is not an antennas, cables or power supply too close issue as I ran the unit off of my pickup 30 feet away and listened to the airplane via the headset I had placed on the cowl.
Next I listened on 123.0 with my handheld while the APRS transmitted and no tone is heard on the Garmin handheld.
Is this maybe some kind of ?multiples of frequency? issue that I can maybe filter out some way?
Is this more likely a problem with the radio or the airframe and wiring?
If it is the radio, is it possibly repairable or should I just write it off and get a good radio?
I stand ready to learn, thanks for your thoughts on this issue.
Tim.
The problem has at least two possible clues.
First for several years I have intermittantly gotten a dual tone when coming into my home area monitoring 123.0, It is kind of an EE-AH sound resembling a donkey. (now stop laughing) It is on a maybe 60 second interval and a very strong signal. I had a guy with some radio monitoring equipment try to hear it a couple of hours after landing one day and we could not find it.
Next clue. I just got an APRS tracker, Micro-Trak RTG. When this unit transmits on 144.35, I get a similar tone. It is different in pitch and not quite as noticeable a difference in front and back as the other tone but still very similar. I can tune .02 up or down and the APRS tone is gone.
This is not an antennas, cables or power supply too close issue as I ran the unit off of my pickup 30 feet away and listened to the airplane via the headset I had placed on the cowl.
Next I listened on 123.0 with my handheld while the APRS transmitted and no tone is heard on the Garmin handheld.
Is this maybe some kind of ?multiples of frequency? issue that I can maybe filter out some way?
Is this more likely a problem with the radio or the airframe and wiring?
If it is the radio, is it possibly repairable or should I just write it off and get a good radio?
I stand ready to learn, thanks for your thoughts on this issue.
Tim.