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  #1  
Old 12-24-2020, 07:18 AM
Camillo Camillo is offline
 
Join Date: Sep 2006
Location: Roma, Italy
Posts: 515
Default Radio noise if GPS signal cable connected

Hallo.
I have an ICOM210 radio and a Garmin 696 GPS, both panel mounted.
I am experiencing continuous radio noise, apart when VHF is receiving audio.
I noticed that if I disconnect the GPS cable the noise goes away.
What could be the problem?
Thanks and happy Christmas.
Camillo
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RV4 IO-320, Catto 3-blade, Christen, I-BILT
Flight time: 1 hour
Status: test flights
www.rv4.it

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Flight time: 350 hours
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  #2  
Old 12-24-2020, 11:55 AM
Ralph Inkster Ralph Inkster is offline
 
Join Date: Feb 2008
Location: Calgary, Alberta
Posts: 1,288
Default

Can you borrow a friend's Garmin antenna puck & see if it reacts the same?
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  #3  
Old 12-24-2020, 02:34 PM
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Roadjunkie1 Roadjunkie1 is offline
 
Join Date: Jun 2017
Location: Erie, Colorado
Posts: 163
Default

Boungiorno! Buon Natale!

Here's a thought: Even though the cables to both the GPS antennae and com antennae are shielded, if they are running close to each other, especially if they are bundled in the same electrical wiring bundle, information in the form of frequency noise can "spill" from the GPS antennae to the com coax. I'd track how close the cables are to each other.

Congratulations on your beginning of test flying!
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  #4  
Old 12-26-2020, 03:36 PM
Camillo Camillo is offline
 
Join Date: Sep 2006
Location: Roma, Italy
Posts: 515
Default Thnsk-you.

Thanks. Yes. It may be cables running together. I will check them.
Flights are going well. She is really a beautiful plane. Even if with afixed-pitch propeller, she has the same take-off performance of my sold -9A constant speed propeller. And bank angle is tremendous... along with speed!
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RV4 IO-320, Catto 3-blade, Christen, I-BILT
Flight time: 1 hour
Status: test flights
www.rv4.it

ROME, Italy
---
RV9A O-320 D1A, Hartzell C/S prop, slider, I-PRCA
Flight time: 350 hours
Status: SOLD
http://nuke.rv9.it
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  #5  
Old 12-26-2020, 04:54 PM
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GalinHdz GalinHdz is offline
 
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Location: KSGJ / TJBQ
Posts: 2,191
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Assicurati che le antenne siano montate ad almeno 60 cm o più, l'una dall'altra. Ciò ha causato problemi ad alcuni aerei, ma non a tutti.

Make sure the antennas are mounted at least 60cm, or more, apart from each other. This has caused problems in some, but not all, aircraft.

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Last edited by GalinHdz : 12-26-2020 at 04:57 PM.
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  #6  
Old 03-08-2021, 07:42 AM
Camillo Camillo is offline
 
Join Date: Sep 2006
Location: Roma, Italy
Posts: 515
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Last Saturday I tried to solve the issue.
I rerouted the earphones shielded audio line, with no result.
Then I tried to switch the radio on and then powering one by one the other stuff (engine off). Well, the source of the problem is the SkyView display. When I switch it ON, the radio starts "creeping". Strange thing it only makes this on 130.00 and not on 125.75.
I believe the strong magnetic field of the SV hits the Icom 210 body.
I wouldn't like to redisegn my panel to relocate the com...
May it help adding some material between the icom and the SV?
Thanks.
Camillo
__________________
RV4 IO-320, Catto 3-blade, Christen, I-BILT
Flight time: 1 hour
Status: test flights
www.rv4.it

ROME, Italy
---
RV9A O-320 D1A, Hartzell C/S prop, slider, I-PRCA
Flight time: 350 hours
Status: SOLD
http://nuke.rv9.it
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  #7  
Old 03-08-2021, 08:00 AM
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bjdecker bjdecker is online now
 
Join Date: Jun 2005
Location: Georgetown, TX
Posts: 646
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You're partially correct -- the SV is radiating RF/RMI probably from the LCD drivers or DC-DC switchers, which is coupling into the audio circuitry. Try to install a ferrite choke around the INPUT's to the ICOM radio and/or loop the wiring through a ferrite core a couple of times. Google Ferrite Bead or Ferrite Choke for sources.

Cheers,

B
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2020 RV-14 QB -- Under construction - Tailcone & Empennage Complete.
2018 RV-7 QB -- Built, Flying
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Last edited by bjdecker : 03-08-2021 at 08:10 AM.
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  #8  
Old 03-08-2021, 09:07 PM
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GalinHdz GalinHdz is offline
 
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Location: KSGJ / TJBQ
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Make sure you have a very good grounds and you don't have some corrosion or dirt in the connections. Make sure they have a good solid contact, especially the ground to the Dynon display and the Icom radio. Don't forget to check and make sure you have a good solid ground connection where the Icom radio antenna attaches to the airframe. Poor grounds at this location has given problems before.

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CP-ASEL-AMEL-IR
FCC Radiotelephone (PG) with Radar Endorsement
2021 Donation made
www.PuertoRicoFlyer.com

Last edited by GalinHdz : 03-08-2021 at 09:11 PM.
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  #9  
Old 03-09-2021, 08:00 AM
Camillo Camillo is offline
 
Join Date: Sep 2006
Location: Roma, Italy
Posts: 515
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Thank.you, Brian and Galin.
I am pretty sure the grounds are OK. I will first install the ferrite gizmos...
I will keep you updated.
Thanks.
Camillo
__________________
RV4 IO-320, Catto 3-blade, Christen, I-BILT
Flight time: 1 hour
Status: test flights
www.rv4.it

ROME, Italy
---
RV9A O-320 D1A, Hartzell C/S prop, slider, I-PRCA
Flight time: 350 hours
Status: SOLD
http://nuke.rv9.it
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