Hi Richard
On the basis that this problem has only manifested itself since your new
radio fit the problem is likely to be somewhere within the altered
avionics setup.
As the problem is noticed by ATC but not on board the aircraft I would
tend to think it is in the mic rather than the tel circuit. My line of
approach in order would be as follows:
1. Try another pair of headsets which you know are OK (not necessarily
ANR).
2. Some intercoms are wired such that they are bypassed if they are
turned off (or have a norm/fail switch). This connects the P1 headset
directly to the radio.
3. Confirm that all you new mic/tel wires are screened and are only
earthed at one end (no earth loops). Check you new wiring is not routed
differently. If it is it might be picking up interference from other
unscreened circuits.
4. If 2 above is not possible temporarily wire the radio to bypass the
intercom.
5. Try the above with a different headset.
6. If the problem is still there with a proven headset connected direct
to the radio it is either the radio or the aerial. Assuming you haven't
changed the aerial (or its cable or connector) then the culprit is
likely to be the radio itself.
Hope this helps. I would be interested to know the results of your
findings.
Nigel Charles
>>-----Original Message-----
>>From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-
>>server@matronics.com] On Behalf Of Richard Iddon
>>Sent: Friday, July 08, 2005 04:26
>>To: europa-list@matronics.com
>>Subject: Europa-List: radio interference
>>
>>
>>I recently fitted an Xcom voice activated intercom to my Microair
radio
>>setup. I also invested in a pair of ANR headsets. Whilst I have
reduced
>>the noise both my passenger and I hear very considerably, I am getting
>>some complaints from ATC units that there is now a lot of background
>>noise in my transmissions, (possibly interference from the
alternator?)
>>
>>Any idea's why this might be?
>>
>>Richard Iddon G-RIXS
>>
>>
>>
>>
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