Mark Browning
Active Member
HELP ! Can anyone offer any advice with aproblem i have thats driving me mad
I have had this fault since my RV-7 first flew last September.
Ten minutes after take off I find that air traffic control can only hear my transmissions as carrier wave.
I initially thought that the problem was with the Radio its self or antenna/ coax. Having checked the coax and antenna including earthing etc. I removed the radio and sent it back to Narco for test and repair; Narco returned the unit to me with no fault found with a $300 invoice.
I had an Air force avionics technician check my installation last week he carried out extensive testing with specialised equipment ( on the ground) but couldn’t find anything Wrong. The modulation was OK, Power out put ok etc ...
He suggested that I replace the radio with another Narco to test.
I did this but again ten minutes after takeoff my transmissions were carrier wave only.This confirms to me that my radio is OK.
Yesterday I flew my RV-7 until my transmissions became carrier wave. At this point I was 15 miles from the tower, so I pulled the circuit breaker for the Sigtronics SCI-4 intercom and made a radio call to ATC. They immediately came back with radio check at strength five. My radio transmissions remained perfect until I switched the intercom back on.
I'm waiting for a reply back from Sigtronics before i go ahead an buy a replacement.
Any ideas ? or advice would be really helpful
My Radio is a Narco 810+
Intercom Sigtronics SCI-4
Cheers
Mark
RV-7 G-LNNE
England
I have had this fault since my RV-7 first flew last September.
Ten minutes after take off I find that air traffic control can only hear my transmissions as carrier wave.
I initially thought that the problem was with the Radio its self or antenna/ coax. Having checked the coax and antenna including earthing etc. I removed the radio and sent it back to Narco for test and repair; Narco returned the unit to me with no fault found with a $300 invoice.
I had an Air force avionics technician check my installation last week he carried out extensive testing with specialised equipment ( on the ground) but couldn’t find anything Wrong. The modulation was OK, Power out put ok etc ...
He suggested that I replace the radio with another Narco to test.
I did this but again ten minutes after takeoff my transmissions were carrier wave only.This confirms to me that my radio is OK.
Yesterday I flew my RV-7 until my transmissions became carrier wave. At this point I was 15 miles from the tower, so I pulled the circuit breaker for the Sigtronics SCI-4 intercom and made a radio call to ATC. They immediately came back with radio check at strength five. My radio transmissions remained perfect until I switched the intercom back on.
I'm waiting for a reply back from Sigtronics before i go ahead an buy a replacement.
Any ideas ? or advice would be really helpful
My Radio is a Narco 810+
Intercom Sigtronics SCI-4
Cheers
Mark
RV-7 G-LNNE
England
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