 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
mkimball(at)gci.net
Guest
|
 Posted: Thu Jan 31, 2008 3:53 pm Post subject: Radio Noise Chevy V8 installation |
 |
|
I have just joined the list today although I have made good use of the AeroElectric website for a long time. I have probably the 3000th radio noise question for the list but mine might be more uncommon due to my uncommon installation. I have a Chevy V8 on a Murphy Super Rebel, using an MSD dual electronic ignition system. Two ignition modules, two coils, one dual pickup distributor, one set of unshielded ignition wires and resistor plugs. There is a switch in the cockpit for choosing one system or the other which basically just switches modules and coils. I have the following avionics which were professionally prewired for me so all I had to do was hook up power, ground and antenna wires.
Garmin 340 Audio Panel
King KX-165 Nav/Com
King 76C Transponder
Centruy NSD360A non-slaved HSI
My battery is grounded in the back directly to the airframe. I have a grounding block on the firewall where all of the avionics are grounded, along with most other things although one ignition module is grounded to the firewall in a different location. The grounding block on the firewall is directly connected to the engine block with a large gauge cable. I have filters on the alternator but the alternator is not the source. (I ran the engine with the alternator solonoid switch open and the alternator drive belt removed. Still have the same noise.) I detect no noise from the stobes. The radio power wire is filtered. I used RG-142/400 antenna wire. The noise is present with or without the audio panel/intercom. I made sure none of the headset jacks were grounding to the airframe and the noise is present in all jacks. The noise is much worse on the NAV side unless there is voice on the NAV frequency, then the noise is about the same. The comm antenna is on the cabin top and the nav antenna is on top of the vertical stab. The noise changes in pitch with engine RPM. It’s a sort of whine with static. My transmissions are reported by the tower as loud and clear.
The ignition modules are mounted inside the cockpit, one on each sidewall just behind the firewall. I can only see this as the source if I have a compromise in both the comm and nav antenna wires or coax connectors that are nearby. I wouldn’t put it past me to screw up more than one coax connector but I was pretty careful installing them on the wires. Someone told me that I might try disconnecting the NAV/COMM ground wire because it might be grounded through the mounting tray and the additional ground might set up a loop. I haven’t tried that yet. I remember reading about making sure the antenna itself was grounded but I think I remember a cork gasket that went under it before mounting to the airframe. Might there be a problem with the way I mounted the comm and nav antennas themselves? If the problem is radiated from the coils, ignition wires, or distributor I’m screwed. Shielding those will be a huge problem.
Any suggestions would be greatly appreciated.
Mike Kimball
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
 |
mprather(at)spro.net
Guest
|
| Posted: Thu Jan 31, 2008 5:12 pm Post subject: Radio Noise Chevy V8 installation |
|
|
Hi Mike,
Are you using (have you tried) spiral wound wires? I am running an old
LSE ignition on my O-200 powered Varieze. This model of LSE has an MSD
amplifier and a pair of MSD coils. When I installed the system I made
custom length Moroso spiral core wires connected to Nippon Denso
(resistor) plugs.
The electronic ignition is _very_ quiet compared to the magneto.
Disconnect the antenna leads from the back of the radio. If the noise is
gone, the propagation mode is radiated...
I have heard of people having noise problems when using solid core wires.
Regards,
Matt-
| Quote: | I have just joined the list today although I have made good use of the
AeroElectric website for a long time. I have probably the 3000th radio
noise question for the list but mine might be more uncommon due to my
uncommon installation. I have a Chevy V8 on a Murphy Super Rebel, using
an
MSD dual electronic ignition system. Two ignition modules, two coils, one
dual pickup distributor, one set of unshielded ignition wires and resistor
plugs. There is a switch in the cockpit for choosing one system or the
other which basically just switches modules and coils. I have the
following
avionics which were professionally prewired for me so all I had to do was
hook up power, ground and antenna wires.
Garmin 340 Audio Panel
King KX-165 Nav/Com
King 76C Transponder
Centruy NSD360A non-slaved HSI
My battery is grounded in the back directly to the airframe. I have a
grounding block on the firewall where all of the avionics are grounded,
along with most other things although one ignition module is grounded to
the
firewall in a different location. The grounding block on the firewall is
directly connected to the engine block with a large gauge cable. I have
filters on the alternator but the alternator is not the source. (I ran
the
engine with the alternator solonoid switch open and the alternator drive
belt removed. Still have the same noise.) I detect no noise from the
stobes. The radio power wire is filtered. I used RG-142/400 antenna
wire.
The noise is present with or without the audio panel/intercom. I made
sure
none of the headset jacks were grounding to the airframe and the noise is
present in all jacks. The noise is much worse on the NAV side unless
there
is voice on the NAV frequency, then the noise is about the same. The comm
antenna is on the cabin top and the nav antenna is on top of the vertical
stab. The noise changes in pitch with engine RPM. It's a sort of whine
with static. My transmissions are reported by the tower as loud and
clear.
The ignition modules are mounted inside the cockpit, one on each sidewall
just behind the firewall. I can only see this as the source if I have a
compromise in both the comm and nav antenna wires or coax connectors that
are nearby. I wouldn't put it past me to screw up more than one coax
connector but I was pretty careful installing them on the wires. Someone
told me that I might try disconnecting the NAV/COMM ground wire because it
might be grounded through the mounting tray and the additional ground
might
set up a loop. I haven't tried that yet. I remember reading about making
sure the antenna itself was grounded but I think I remember a cork gasket
that went under it before mounting to the airframe. Might there be a
problem with the way I mounted the comm and nav antennas themselves? If
the
problem is radiated from the coils, ignition wires, or distributor I'm
screwed. Shielding those will be a huge problem.
Any suggestions would be greatly appreciated.
Mike Kimball
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
mkimball(at)gci.net
Guest
|
| Posted: Thu Jan 31, 2008 5:32 pm Post subject: Radio Noise Chevy V8 installation |
|
|
Taylor 409 spiral wound wires. Supposed to be very good wires and good for
noise suppression. I'm pretty sure I did check the noise with the antenna
disconnected and the noise is gone. I'll recheck that when it warms up (-25
F today and the near future here in Fairbanks, AK and the plane is outside)
That's why I am interested in possible antenna mounting issues. Thanks.
Keep the suggestions coming.
Mike
--
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
mprather(at)spro.net
Guest
|
|
| Back to top |
|
|
n801bh(at)NetZero.com
Guest
|
| Posted: Thu Jan 31, 2008 9:16 pm Post subject: Radio Noise Chevy V8 installation |
|
|
Hi Mike. I have almost the exact same set up as yours, altho mine is a stroker 347 all aluminum Ford. Both my ignition boxes are on the outside of the firewall along side the coil switcher. I did use the high dollar blue max racing ignition wires and I have no noise in any of my radios or intercom. My gut feeling is the noise is in the wires, You can go to my website and browse through the pics and see how mine is set up.
do not archive
Ben Haas
N801BH
www.haaspowerair.com
-- Mike Kimball <mkimball(at)gci.net> wrote:
I have just joined the list today although I have made good use of the AeroElectric website for a long time. I have probably the 3000th radio noise question for the list but mine might be more uncommon due to my uncommon installation. I have a Chevy V8 on a Murphy Super Rebel, using an MSD dual electronic ignition system. Two ignition modules, two coils, one dual pickup distributor, one set of unshielded ignition wires and resistor plugs. There is a switch in the cockpit for choosing one system or the other which basically just switches modules and coils. I have the following avionics which were professionally prewired for me so all I had to do was hook up power, ground and antenna wires.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
Garmin 340 Audio Panel
King KX-165 Nav/Com
King 76C Transponder
Centruy NSD360A non-slaved HSI
My battery is grounded in the back directly to the airframe. I have a grounding block on the firewall where all of the avionics are grounded, along with most other things although one ignition module is grounded to the firewall in a different location. The grounding block on the firewall is directly connected to the engine block with a large gauge cable. I have filters on the alternator but the alternator is not the source. (I ran the engine with the alternator solonoid switch open and the alternator drive belt removed. Still have the same noise.) I detect no noise from the stobes. The radio power wire is filtered. I used RG-142/400 antenna wire. The noise is present with or without the audio panel/intercom. I made sure none of the headset jacks were grounding to the airframe and the noise is present in all jacks. The noise is much worse on the NAV side unless there is voice on the NAV frequency, then the noise is about the same. The comm antenna is on the cabin top and the nav antenna is on top of the vertical stab. The noise changes in pitch with engine RPM. It’s a sort of whine with static. My transmissions are reported by the tower as loud and clear.
The ignition modules are mounted inside the cockpit, one on each sidewall just behind the firewall. I can only see this as the source if I have a compromise in both the comm and nav antenna wires or coax connectors that are nearby. I wouldn’t put it past me to screw up more than one coax connector but I was pretty careful installing them on the wires. Someone told me that I might try disconnecting the NAV/COMM ground wire because it might be grounded through the mounting tray and the additional ground might set up a loop. I haven’t tried that yet. I remember reading about making sure the antenna itself was grounded but I think I remember a cork gasket that went under it before mounting to the airframe. Might there be a problem with the way I mounted the comm and nav antennas themselves? If the problem is radiated from the coils, ignition wires, or distributor I’m screwed. Shielding those will be a huge problem.
Any suggestions would be greatly appreciated.
Mike Kimball
_____________________________________________________________
Handyman Franchises. Click Here.
[quote][b]
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
mkimball(at)gci.net
Guest
|
| Posted: Fri Feb 01, 2008 1:08 pm Post subject: Radio Noise Chevy V8 installation |
|
|
Holley 650 double pumper with a special plate that goes between the float
bowl and mixture plate that gives me mixture control in the cockpit. I am
also running dual electric fuel pumps with one way check valves. I have
eliminated the fuel pumps as the source.
Mike
--
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
mkimball(at)gci.net
Guest
|
| Posted: Fri Feb 01, 2008 1:24 pm Post subject: Radio Noise Chevy V8 installation |
|
|
A different set of spark plug wires is certainly a very simple thing to try. Just costs money, but I think I will try the blue max wires since they are working for you. If I still have noise, I will relocate one of the ignition boxes to outside the firewall. If that solves the problem I will relocate the second box outside the firewall. Nice plane! Nice engine installation!
Mike
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of n801bh(at)netzero.com
Sent: Thursday, January 31, 2008 8:11 PM
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Radio Noise Chevy V8 installation
Hi Mike. I have almost the exact same set up as yours, altho mine is a stroker 347 all aluminum Ford. Both my ignition boxes are on the outside of the firewall along side the coil switcher. I did use the high dollar blue max racing ignition wires and I have no noise in any of my radios or intercom. My gut feeling is the noise is in the wires, You can go to my website and browse through the pics and see how mine is set up.
do not archive
Ben Haas
N801BH
www.haaspowerair.com
-- Mike Kimball <mkimball(at)gci.net> wrote:
I have just joined the list today although I have made good use of the AeroElectric website for a long time. I have probably the 3000th radio noise question for the list but mine might be more uncommon due to my uncommon installation. I have a Chevy V8 on a Murphy Super Rebel, using an MSD dual electronic ignition system. Two ignition modules, two coils, one dual pickup distributor, one set of unshielded ignition wires and resistor plugs. There is a switch in the cockpit for choosing one system or the other which basically just switches modules and coils. I have the following avionics which were professionally prewired for me so all I had to do was hook up power, ground and antenna wires.
Garmin 340 Audio Panel
King KX-165 Nav/Com
King 76C Transponder
Centruy NSD360A non-slaved HSI
My battery is grounded in the back directly to the airframe. I have a grounding block on the firewall where all of the avionics are grounded, along with most other things although one ignition module is grounded to the firewall in a different location. The grounding block on the firewall is directly connected to the engine block with a large gauge cable. I have filters on the alternator but the alternator is not the source. (I ran the engine with the alternator solonoid switch open and the alternator drive belt removed. Still have the same noise.) I detect no noise from the stobes. The radio power wire is filtered. I used RG-142/400 antenna wire. The noise is present with or without the audio panel/intercom. I made sure none of the headset jacks were grounding to the airframe and the noise is present in all jacks. The noise is much worse on the NAV side unless there is voice on the NAV frequency, then the noise is about the same. The comm antenna is on the cabin top and the nav antenna is on top of the vertical stab. The noise changes in pitch with engine RPM. It’s a sort of whine with static. My transmissions are reported by the tower as loud and clear.
The ignition modules are mounted inside the cockpit, one on each sidewall just behind the firewall. I can only see this as the source if I have a compromise in both the comm and nav antenna wires or coax connectors that are nearby. I wouldn’t put it past me to screw up more than one coax connector but I was pretty careful installing them on the wires. Someone told me that I might try disconnecting the NAV/COMM ground wire because it might be grounded through the mounting tray and the additional ground might set up a loop. I haven’t tried that yet. I remember reading about making sure the antenna itself was grounded but I think I remember a cork gasket that went under it before mounting to the airframe. Might there be a problem with the way I mounted the comm and nav antennas themselves? If the problem is radiated from the coils, ignition wires, or distributor I’m screwed. Shielding those will be a huge problem.
Any suggestions would be greatly appreciated.
Mike Kimball
_____________________________________________________________
Handyman Franchises. Click Here. | Quote: | | http://www.matronics.com/Navigator?AeroElectric-Listhttp://forums.matronics.comhttp://www.matronics.com/contribution |
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
klehman(at)albedo.net
Guest
|
| Posted: Fri Feb 01, 2008 2:40 pm Post subject: Radio Noise Chevy V8 installation |
|
|
If the noise is still there with the antennae disconnected from the
radios then I presume it really is radiated. Bob often recommends
running things off a separate battery to be certain the noise is not
conducting in on the 12 volt supply. I don't see specs for the Taylor
409 spiral wound wires. They sound like quality wires though and I
believe others have used them successfully. Is the problem ever related
to wire assembly? I wanted to make my own wires but Magnecor gave me
decent pricing and indicated they had a lot of problems with customer
assembled wires. Also I've heard a few guys say they had noise problems
with specific spark plugs such as iridium. Could radiated noise be
harmonics coming from the on off pulses in the 12 volt wiring to the
ignition coils? I can imagine that but I don't know if it is likely.
Regarding the antenna, I followed Bob's advice and did not use any
gaskets under the antenna. Made sure it contacted bare metal where the
bolts went through the skin and added some sealant around the outer
edge. Again I don't know if poor antenna grounding can cause this kind
of issue though?
If the antenna coax checks out OK with an ohm meter (continuity of core
and shield and no shorts)I'd guess the problem is unlikely to be the
coax connectors.
Mike - to help me follow this discussion - the ignition coils and joiner
are ahead of the firewall aren't they?
Ken
n801bh(at)netzero.com wrote:
| Quote: | Hi Mike. I have almost the exact same set up as yours, altho mine is a
stroker 347 all aluminum Ford. Both my ignition boxes are on the
outside of the firewall along side the coil switcher. I did use the high
dollar blue max racing ignition wires and I have no noise in any of my
radios or intercom. My gut feeling is the noise is in the wires, You can
go to my website and browse through the pics and see how mine is set up.
do not archive
Ben Haas
N801BH
www.haaspowerair.com
-- Mike Kimball <mkimball(at)gci.net> wrote:
I have just joined the list today although I have made good use of the
AeroElectric website for a long time. I have probably the 3000^th radio
noise question for the list but mine might be more uncommon due to my
uncommon installation. I have a Chevy V8 on a Murphy Super Rebel, using
an MSD dual electronic ignition system. Two ignition modules, two
coils, one dual pickup distributor, one set of unshielded ignition wires
and resistor plugs. There is a switch in the cockpit for choosing one
system or the other which basically just switches modules and coils. I
have the following avionics which were professionally prewired for me so
all I had to do was hook up power, ground and antenna wires.
Garmin 340 Audio Panel
King KX-165 Nav/Com
King 76C Transponder
Centruy NSD360A non-slaved HSI
My battery is grounded in the back directly to the airframe. I have a
grounding block on the firewall where all of the avionics are grounded,
along with most other things although one ignition module is grounded to
the firewall in a different location. The grounding block on the
firewall is directly connected to the engine block with a large gauge
cable. I have filters on the alternator but the alternator is not the
source. (I ran the engine with the alternator solonoid switch open and
the alternator drive belt removed. Still have the same noise.) I
detect no noise from the stobes. The radio power wire is filtered. I
used RG-142/400 antenna wire. The noise is present with or without the
audio panel/intercom. I made sure none of the headset jacks were
grounding to the airframe and the noise is present in all jacks. The
noise is much worse on the NAV side unless there is voice on the NAV
frequency, then the noise is about the same. The comm antenna is on the
cabin top and the nav antenna is on top of the vertical stab. The noise
changes in pitch with engine RPM. It’s a sort of whine with static. My
transmissions are reported by the tower as loud and clear.
The ignition modules are mounted inside the cockpit, one on each
sidewall just behind the firewall. I can only see this as the source if
I have a compromise in both the comm and nav antenna wires or coax
connectors that are nearby. I wouldn’t put it past me to screw up more
than one coax connector but I was pretty careful installing them on the
wires. Someone told me that I might try disconnecting the NAV/COMM
ground wire because it might be grounded through the mounting tray and
the additional ground might set up a loop. I haven’t tried that yet. I
remember reading about making sure the antenna itself was grounded but I
think I remember a cork gasket that went under it before mounting to the
airframe. Might there be a problem with the way I mounted the comm and
nav antennas themselves? If the problem is radiated from the coils,
ignition wires, or distributor I’m screwed. Shielding those will be a
huge problem.
Any suggestions would be greatly appreciated.
Mike Kimball
|
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
mkimball(at)gci.net
Guest
|
| Posted: Fri Feb 01, 2008 3:02 pm Post subject: Radio Noise Chevy V8 installation |
|
|
Yes. The coils and joiner are on the engine side of the firewall.
Mike
--
| | - The Matronics AeroElectric-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?AeroElectric-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
