New pilot, need help! I bought a Vertex Standard handheld radio for use in my Aeronca Chief. Worked fine for a couple of days, but started to squeal ( feedback? ) when I push the PTT switch. I have a Lightspeed LT 20 and a Bose Quiet Comfort 15 headset, and an external PTT switch from Aircraft Spruce and it does the same on both. Bought an I-Com A-24 after I sent the Vertex off To get checked out and it does the same thing. Makes no difference with or without the intercom ( Sigtronics) in line. Dealer says there is nothing wrong with the Vertex radio, but has no suggestions as to what is wrong. Called I-Com, and the guy I talked to didn't have a clue, either.
I've heard that the handhelds don't play well with noise cancelling headsets. You might try a simple headset without noise cancelling.
The problem is RF Feedback most probably from the PTT line. Not all PTT lines are created equal. Find another pilot at the airport with the same radio and try his/her PTT cord you might get lucky and find a different one works. Next I would get a couple of spilt ferrite chokes and place them on the cords where the PTT and the headset connect to the hand held. Radio Shack used to sell these, they might still. These are the lumps that you see on some computer cables. They are there for the same reason.
And as someone else said, try a non-noise cancelling headset although if I were to venture a guess, I would expect a headset with internal electronics to have adequate built-in shielding.
Sometimes just coiling the excess cord in a 2 or 3 or 4 inch circle and securing it with a few tie wraps will act as a choke and solve the problem.
Some handhelds, some headsets, perhaps. I've been using a Flightcom Denali ANR headset with an ICOM handheld for years without a problem.
Originally Posted by rafrench
The fact that it worked fine initially tells you something changed, and the fact that it does the same with the ICOM indicates that something's probably funky with your wiring.
Note that if you use the radio-mounted PTT, the built-in microphone of the handheld radio is activated, even if a headset is plugged in. This could cause some weirdness.
I had this problem when using an ICOM handheld with their headset adapter cable and special push-to-talk switch (which uses a smaller plug). My old Telex headset would work OK, but my David Clark headset would squeal with feedback when I transmitted.
ICOM knowledge base article 64JA571413 describes this problem for A6/A24 handhelds and shows how to install two ferrite beads on the headset cable. Their part number for a snap-on bead is 6910013530 ($6.75 from ACS). That fix is a little pricey, but worked for me.
Radio Problem work around
I have the same problem with my Vertex radio. A call to the company didn't get me much other than an opinion that there might be an impedance issue between my radio and headset. However I found that if I run things through an intercom box that the issue goes away as long as I use the PTT button on the intercom.
Originally Posted by RGatewood