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mhilderbrand
Joined: 28 Sep 2006 Posts: 36
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Posted: Mon Oct 19, 2009 5:54 am Post subject: Radio popping |
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Hey guys,
I am doing some initial ground rounds with my Jab3300 engine and was noticing a popping noise in the headsets - while receiving ONLY. The popping noise is pretty bad. At first I thought is might have been the other aircraft's radio (flying in the pattern), but after tuning to a local ATIS I got the same popping sound. I am just trying to see if it might be something obvious, something that one of you might have experienced as well? It does not happen when the engine is not running. I am thinking that maybe I should start out by buying resistor plugs? I am NOT an electrical person at all... but I did try to wire per the Aeroelectric manual.
Any thoughts?
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
[quote][b]
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jetboy
Joined: 22 Jul 2006 Posts: 233
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Posted: Mon Oct 19, 2009 11:42 pm Post subject: Re: Radio popping |
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popping noises can occur due to the AC dynamo regulator. If that is the source, it will not be present if the AC leads are disconnected.
Another clue is that this type of noise will change in nature during the charging of the battery. It is not troublesome if the installation is wired according to the advice in the Jabiru manual. Simply put this means the regulator + wires connect direct to battery + , regulator ground connect directly to batt ground, all avionics ground to common stud on firewall, headset sockets are not in contact with airframe (unless they are on the same metal panel as the intercom/radio) and the battery capacity is one of 20 amp-hours or greater.
Ralph
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Float Flyr
Joined: 19 Jul 2006 Posts: 2704 Location: Campbellton, Newfoundland
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Posted: Thu Oct 22, 2009 6:20 am Post subject: Radio popping |
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This is Thursday morning so I’m taking a chanced you haven’t gotten any answers or even a fix yet.
First thing is, does the popping change rate with the rpm of the engine?
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Monday, October 19, 2009 11:20 AM
To: jabiruengine-list(at)matronics.com
Subject: Radio popping
Hey guys,
I am doing some initial ground rounds with my Jab3300 engine and was noticing a popping noise in the headsets - while receiving ONLY. The popping noise is pretty bad. At first I thought is might have been the other aircraft's radio (flying in the pattern), but after tuning to a local ATIS I got the same popping sound. I am just trying to see if it might be something obvious, something that one of you might have experienced as well? It does not happen when the engine is not running. I am thinking that maybe I should start out by buying resistor plugs? I am NOT an electrical person at all... but I did try to wire per the Aeroelectric manual.
Any thoughts?
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
Quote: | http://www.matronics.com/Navigator?JabiruEngine-List | 0123456789
[quote][b]
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Kitfox III-A
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mhilderbrand
Joined: 28 Sep 2006 Posts: 36
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Posted: Thu Oct 22, 2009 12:34 pm Post subject: Radio popping |
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Noel,
I could not appreciate if the popping changes rate with RPM during the ground running operations. My attention was really focused on RPM, EGT, and CHTs at the time (trying to fine-tune an Aerocarb for first flight operation). At the time I was aggressively changing RPM but was on the local frequency - traffic transmissions were too short in nature to notice a change in popping. When no one is transmitting everything is normal.
I will listen to ATIS continuously on Friday while running the engine and report back.
Thanks!
Michael Hilderbrand
Derby, KS
www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Thursday, October 22, 2009 11:48:06 AM
Subject: RE: Radio popping
This is Thursday morning so I’m taking a chanced you haven’t gotten any answers or even a fix yet.
First thing is, does the popping change rate with the rpm of the engine?
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Monday, October 19, 2009 11:20 AM
To: jabiruengine-list(at)matronics.com
Subject: Radio popping
Hey guys,
I am doing some initial ground rounds with my Jab3300 engine and was noticing a popping noise in the headsets - while receiving ONLY. The popping noise is pretty bad. At first I thought is might have been the other aircraft's radio (flying in the pattern), but after tuning to a local ATIS I got the same popping sound. I am just trying to see if it might be something obvious, something that one of you might have experienced as well? It does not happen when the engine is not running. I am thinking that maybe I should start out by buying resistor plugs? I am NOT an electrical person at all... but I did try to wire per the Aeroelectric manual.
Any thoughts?
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
Quote: |
http://www.matronics.com/Navigator?JabiruEngine-List
| 0123456789
http://www.matronics.com/Na======================== _ms.matronics.com/" target=_blank rel=nofollow>http://forums.matronics.cwww.matronics.com/contribution" target=_blank rel=nofollow>http://www.m===================== [/b][/quote]
[quote][b]
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rickofudall
Joined: 19 Sep 2009 Posts: 1392 Location: Udall, KS, USA
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Posted: Thu Oct 22, 2009 1:30 pm Post subject: Radio popping |
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You know, Mike, the story of your first flight, trouble shooting the radio, the Aerocarb on a Jabby, etc. would all make great articles for your local EAA Chapter newsletter and I know your chapter's newsletter editor would be VERY grateful.
Rick Girard
PS If I can be of help tomorrow give me a call and I'll be happy to give you a hand.
On Thu, Oct 22, 2009 at 3:33 PM, Michael Hilderbrand <m_hilderbrand(at)sbcglobal.net (m_hilderbrand(at)sbcglobal.net)> wrote:
[quote]
Noel,
I could not appreciate if the popping changes rate with RPM during the ground running operations. My attention was really focused on RPM, EGT, and CHTs at the time (trying to fine-tune an Aerocarb for first flight operation). At the time I was aggressively changing RPM but was on the local frequency - traffic transmissions were too short in nature to notice a change in popping. When no one is transmitting everything is normal.
I will listen to ATIS continuously on Friday while running the engine and report back.
Thanks!
Michael Hilderbrand
Derby, KS
www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca (noelloveys(at)yahoo.ca)>
To: jabiruengine-list(at)matronics.com (jabiruengine-list(at)matronics.com)
Sent: Thursday, October 22, 2009 11:48:06 AM
Subject: RE: JabiruEngine-List: Radio popping
This is Thursday morning so I’m taking a chanced you haven’t gotten any answers or even a fix yet.
First thing is, does the popping change rate with the rpm of the engine?
Noel
From: owner-jabiruengine-list-server(at)matronics.com (owner-jabiruengine-list-server(at)matronics.com) [mailto:owner-jabiruengine-list-server(at)matronics.com (owner-jabiruengine-list-server(at)matronics.com)] On Behalf Of Michael Hilderbrand
Sent: Monday, October 19, 2009 11:20 AM
To: jabiruengine-list(at)matronics.com (jabiruengine-list(at)matronics.com)
Subject: Radio popping
Hey guys,
I am doing some initial ground rounds with my Jab3300 engine and was noticing a popping noise in the headsets - while receiving ONLY. The popping noise is pretty bad. At first I thought is might have been the other aircraft's radio (flying in the pattern), but after tuning to a local ATIS I got the same popping sound. I am just trying to see if it might be something obvious, something that one of you might have experienced as well? It does not happen when the engine is not running. I am thinking that maybe I should start out by buying resistor plugs? I am NOT an electrical person at all... but I did try to wire per the Aeroelectric manual.
Any thoughts?
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
0123 4567 89
http://www.matronics.com/Na======================== _ms.matronics.com/" target=_blank rel=nofollow>http://forums.matronics.cwww.matronics.com/contribution" target=_blank rel=nofollow>http://www.m=====================
0[b]
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Float Flyr
Joined: 19 Jul 2006 Posts: 2704 Location: Campbellton, Newfoundland
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Posted: Fri Oct 23, 2009 1:56 pm Post subject: Radio popping |
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Michael:
If you find the popping frequency increases with rpm then your problem is most probably a bad ground in your audio section. Audio connecting lines should only be shield grounded at the feed end… never at both ends. The grounds do however need to be very clean. You will find, as I have, better than 90% of interference problems in aircraft are caused by poor grounding somewhere. The trick is to figure out where.
If you find the popping does not increase with throttle then the possibility is a heavy capacitor of sufficient voltage across the DC buss on your radios should cure it.
In the meantime the R582 engine ( you may have one) is a bit of an oddball in that it is recommended to use both resistor caps (5K Ohm) and 5K Ohm plugs.
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Thursday, October 22, 2009 6:04 PM
To: jabiruengine-list(at)matronics.com
Subject: Re: Radio popping
Noel,
I could not appreciate if the popping changes rate with RPM during the ground running operations. My attention was really focused on RPM, EGT, and CHTs at the time (trying to fine-tune an Aerocarb for first flight operation). At the time I was aggressively changing RPM but was on the local frequency - traffic transmissions were too short in nature to notice a change in popping. When no one is transmitting everything is normal.
I will listen to ATIS continuously on Friday while running the engine and report back.
Thanks!
Michael Hilderbrand
Derby, KS
www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Thursday, October 22, 2009 11:48:06 AM
Subject: RE: Radio popping
This is Thursday morning so I’m taking a chanced you haven’t gotten any answers or even a fix yet.
First thing is, does the popping change rate with the rpm of the engine?
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Monday, October 19, 2009 11:20 AM
To: jabiruengine-list(at)matronics.com
Subject: Radio popping
Hey guys,
I am doing some initial ground rounds with my Jab3300 engine and was noticing a popping noise in the headsets - while receiving ONLY. The popping noise is pretty bad. At first I thought is might have been the other aircraft's radio (flying in the pattern), but after tuning to a local ATIS I got the same popping sound. I am just trying to see if it might be something obvious, something that one of you might have experienced as well? It does not happen when the engine is not running. I am thinking that maybe I should start out by buying resistor plugs? I am NOT an electrical person at all... but I did try to wire per the Aeroelectric manual.
Any thoughts?
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
Quote: | Â http://www.matronics.com/Navigator?JabiruEngine-Listhttp://forums.matronics.comhttp://www.matronics.com/contribution |
http://www.matronics.com/Na======================== _ms.matronics.com/" target=_blank rel=nofollow>http://forums.matronics.cwww.matronics.com/contribution" target=_blank rel=nofollow>http://www.m=====================
01234567890123456
[quote][b]
| - The Matronics JabiruEngine-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?JabiruEngine-List |
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_________________ Noel Loveys
Kitfox III-A
Aerocet 1100 Floats |
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mhilderbrand
Joined: 28 Sep 2006 Posts: 36
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Posted: Fri Oct 23, 2009 7:28 pm Post subject: Radio popping |
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Noel,
Yes! It does increase with RPM. I was looking at my mag wires today and noticed that I made a pigtail from the shield material in the wire (side connected to engine) and grounded this to the firewall ground - all my grounds connect eventually. The panel ground leads to the firewall ground - which leads to the neg battery. I did not shield any of the wires to or from my com radio - the instructions did not mention it, anyways.. something to look at I guess.
Thanks!
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Friday, October 23, 2009 7:25:28 PM
Subject: RE: Radio popping
Michael:
If you find the popping frequency increases with rpm then your problem is most probably a bad ground in your audio section. Audio connecting lines should only be shield grounded at the feed end… never at both ends. The grounds do however need to be very clean. You will find, as I have, better than 90% of interference problems in aircraft are caused by poor grounding somewhere. The trick is to figure out where.
If you find the popping does not increase with throttle then the possibility is a heavy capacitor of sufficient voltage across the DC buss on your radios should cure it.
In the meantime the R582 engine ( you may have one) is a bit of an oddball in that it is recommended to use both resistor caps (5K Ohm) and 5K Ohm plugs.
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Thursday, October 22, 2009 6:04 PM
To: jabiruengine-list(at)matronics.com
Subject: Re: JabiruEngine-List: Radio popping
Noel,
I could not appreciate if the popping changes rate with RPM during the ground running operations. My attention was really focused on RPM, EGT, and CHTs at the time (trying to fine-tune an Aerocarb for first flight operation). At the time I was aggressively changing RPM but was on the local frequency - traffic transmissions were too short in nature to notice a change in popping. When no one is transmitting everything is normal.
I will listen to ATIS continuously on Friday while running the engine and report back.
Thanks!
Michael Hilderbrand
Derby, KS
www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Thursday, October 22, 2009 11:48:06 AM
Subject: RE: Radio popping
This is Thursday morning so I’m taking a chanced you haven’t gotten any answers or even a fix yet.
First thing is, does the popping change rate with the rpm of the engine?
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Monday, October 19, 2009 11:20 AM
To: jabiruengine-list(at)matronics.com
Subject: JabiruEngine-List: Radio popping
Hey guys,
I am doing some initial ground rounds with my Jab3300 engine and was noticing a popping noise in the headsets - while receiving ONLY. The popping noise is pretty bad. At first I thought is might have been the other aircraft's radio (flying in the pattern), but after tuning to a local ATIS I got the same popping sound. I am just trying to see if it might be something obvious, something that one of you might have experienced as well? It does not happen when the engine is not running. I am thinking that maybe I should start out by buying resistor plugs? I am NOT an electrical person at all... but I did try to wire per the Aeroelectric manual.
Any thoughts?
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
Quote: | http://www.matronics.com/Navigator?JabiruEngine-Listhttp://forums.matronics.comhttp://www.matronics.com/contribution |
http://www.matronics.com/Na======================== _ms.matronics.com/" target=_blank rel=nofollow>http://forums.matronics.cwww.matronics.com/contribution" target=_blank rel=nofollow>http://www.m=====================
01234567890123456
7
[quote][b]
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Float Flyr
Joined: 19 Jul 2006 Posts: 2704 Location: Campbellton, Newfoundland
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Posted: Sun Oct 25, 2009 12:50 pm Post subject: Radio popping |
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Because your interference speeds up with rpm it suggests a few things.Â
First of all because aircraft and towers you are talking to do not hear the interference it means the problem is not radio frequency (RF). This is great as it eliminates checking all the coax wires to your antennas.
A few other possibilities exist.
One can be a shield on a shielded wire that is grounded at both ends. Grounding the shield at both ends turns the shield from a shield to an inductor. Sort of like a guard turning to the other side….Â
Another possibility is the p leads for your magnetos should be shielded wires grounded at one end… preferably the firewall end.Â
I’m not sure if you are using an audio panel or not but if you are, all the interconnect wires going between the audio panel and the other items of your stack should be made using shielded wire grounded at the audio panel end. That goes for things like the mic and phone lines going to the jacks.
Once you have checked out those few items and made sure the case of your radio is also securely grounded if you still get the interference try resistor plugs or even resistor plug caps.
Keep us all informed on how things turn out for you.
One small piece of advice is there are literally hundreds of people around who have a lot of experience, not to mention equipment who are radio amateurs. It may not hurt to have one assist you in checking out your installation.
I also recommend to everyone to draw a block diagram of your installation as you do your check out… include things in your diagram such as wire colours or numbers and ground placements. Keep the diagram so you can refer to it if you ever want to change your installation or track down another problem.
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Saturday, October 24, 2009 12:51 AM
To: jabiruengine-list(at)matronics.com
Subject: Re: Radio popping
Noel,
Yes! It does increase with RPM. I was looking at my mag wires today and noticed that I made a pigtail from the shield material in the wire (side connected to engine) and grounded this to the firewall ground - all my grounds connect eventually. The panel ground leads to the firewall ground - which leads to the neg battery. I did not shield any of the wires to or from my com radio - the instructions did not mention it, anyways.. something to look at I guess.
Thanks!
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Friday, October 23, 2009 7:25:28 PM
Subject: RE: Radio popping
Michael:
If you find the popping frequency increases with rpm then your problem is most probably a bad ground in your audio section. Audio connecting lines should only be shield grounded at the feed end… never at both ends. The grounds do however need to be very clean. You will find, as I have, better than 90% of interference problems in aircraft are caused by poor grounding somewhere. The trick is to figure out where.
If you find the popping does not increase with throttle then the possibility is a heavy capacitor of sufficient voltage across the DC buss on your radios should cure it.
In the meantime the R582 engine ( you may have one) is a bit of an oddball in that it is recommended to use both resistor caps (5K Ohm) and 5K Ohm plugs.
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Thursday, October 22, 2009 6:04 PM
To: jabiruengine-list(at)matronics.com
Subject: Re: Radio popping
Noel,
I could not appreciate if the popping changes rate with RPM during the ground running operations. My attention was really focused on RPM, EGT, and CHTs at the time (trying to fine-tune an Aerocarb for first flight operation). At the time I was aggressively changing RPM but was on the local frequency - traffic transmissions were too short in nature to notice a change in popping. When no one is transmitting everything is normal.
I will listen to ATIS continuously on Friday while running the engine and report back.
Thanks!
Michael Hilderbrand
Derby, KS
www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Thursday, October 22, 2009 11:48:06 AM
Subject: RE: Radio popping
This is Thursday morning so I’m taking a chanced you haven’t gotten any answers or even a fix yet.
First thing is, does the popping change rate with the rpm of the engine?
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Monday, October 19, 2009 11:20 AM
To: jabiruengine-list(at)matronics.com
Subject: Radio popping
Hey guys,
I am doing some initial ground rounds with my Jab3300 engine and was noticing a popping noise in the headsets - while receiving ONLY. The popping noise is pretty bad. At first I thought is might have been the other aircraft's radio (flying in the pattern), but after tuning to a local ATIS I got the same popping sound. I am just trying to see if it might be something obvious, something that one of you might have experienced as well? It does not happen when the engine is not running. I am thinking that maybe I should start out by buying resistor plugs? I am NOT an electrical person at all... but I did try to wire per the Aeroelectric manual.
Any thoughts?
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
Quote: | http://www.matronics.com/Navigator?JabiruEngine-Listhttp://forums.matronics.comhttp://www.matronics.com/contribution |
http://www.matronics.com/Na======================== _ms.matronics.com/" target=_blank rel=nofollow>http://forums.matronics.cwww.matronics.com/contribution" target=_blank rel=nofollow>http://www.m=====================
0123
4
567890123456789 Quote: | http://www.matronics.com/Navigator?JabiruEngine-List | 0 Quote: | http://www.matronics.com/Navigator?JabiruEngine-List | 1 Quote: | http://www.matronics.com/Navigator?JabiruEngine-List | 2 Quote: | http://www.matronics.com/Navigator?JabiruEngine-List | 3 Quote: | http://www.matronics.com/Navigator?JabiruEngine-List | 4
[quote][b]
| - The Matronics JabiruEngine-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?JabiruEngine-List |
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_________________ Noel Loveys
Kitfox III-A
Aerocet 1100 Floats |
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mhilderbrand
Joined: 28 Sep 2006 Posts: 36
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Posted: Sun Oct 25, 2009 7:20 pm Post subject: Radio popping |
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Noel, I appreciate all your help. I will check & double check all my wires. I guess if all else fails Bob knockoll's (sp) just lives 20 or so miles away... maybe he would look at it.
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Sunday, October 25, 2009 6:17:18 PM
Subject: RE: Radio popping
Because your interference speeds up with rpm it suggests a few things.
First of all because aircraft and towers you are talking to do not hear the interference it means the problem is not radio frequency (RF). This is great as it eliminates checking all the coax wires to your antennas.
A few other possibilities exist.
One can be a shield on a shielded wire that is grounded at both ends. Grounding the shield at both ends turns the shield from a shield to an inductor. Sort of like a guard turning to the other side….
Another possibility is the p leads for your magnetos should be shielded wires grounded at one end… preferably the firewall end.
I’m not sure if you are using an audio panel or not but if you are, all the interconnect wires going between the audio panel and the other items of your stack should be made using shielded wire grounded at the audio panel end. That goes for things like the mic and phone lines going to the jacks.
Once you have checked out those few items and made sure the case of your radio is also securely grounded if you still get the interference try resistor plugs or even resistor plug caps.
Keep us all informed on how things turn out for you.
One small piece of advice is there are literally hundreds of people around who have a lot of experience, not to mention equipment who are radio amateurs. It may not hurt to have one assist you in checking out your installation.
I also recommend to everyone to draw a block diagram of your installation as you do your check out… include things in your diagram such as wire colours or numbers and ground placements. Keep the diagram so you can refer to it if you ever want to change your installation or track down another problem.
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Saturday, October 24, 2009 12:51 AM
To: jabiruengine-list(at)matronics.com
Subject: Re: Radio popping
Noel,
Yes! It does increase with RPM. I was looking at my mag wires today and noticed that I made a pigtail from the shield material in the wire (side connected to engine) and grounded this to the firewall ground - all my grounds connect eventually. The panel ground leads to the firewall ground - which leads to the neg battery. I did not shield any of the wires to or from my com radio - the instructions did not mention it, anyways.. something to look at I guess.
Thanks!
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Friday, October 23, 2009 7:25:28 PM
Subject: RE: Radio popping
Michael:
If you find the popping frequency increases with rpm then your problem is most probably a bad ground in your audio section. Audio connecting lines should only be shield grounded at the feed end… never at both ends. The grounds do however need to be very clean. You will find, as I have, better than 90% of interference problems in aircraft are caused by poor grounding somewhere. The trick is to figure out where.
If you find the popping does not increase with throttle then the possibility is a heavy capacitor of sufficient voltage across the DC buss on your radios should cure it.
In the meantime the R582 engine ( you may have one) is a bit of an oddball in that it is recommended to use both resistor caps (5K Ohm) and 5K Ohm plugs.
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Thursday, October 22, 2009 6:04 PM
To: jabiruengine-list(at)matronics.com
Subject: Re: Radio popping
Noel,
I could not appreciate if the popping changes rate with RPM during the ground running operations. My attention was really focused on RPM, EGT, and CHTs at the time (trying to fine-tune an Aerocarb for first flight operation). At the time I was aggressively changing RPM but was on the local frequency - traffic transmissions were too short in nature to notice a change in popping. When no one is transmitting everything is normal.
I will listen to ATIS continuously on Friday while running the engine and report back.
Thanks!
Michael Hilderbrand
Derby, KS
www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Thursday, October 22, 2009 11:48:06 AM
Subject: RE: Radio popping
This is Thursday morning so I’m taking a chanced you haven’t gotten any answers or even a fix yet.
First thing is, does the popping change rate with the rpm of the engine?
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Monday, October 19, 2009 11:20 AM
To: jabiruengine-list(at)matronics.com
Subject: JabiruEngine-List: Radio popping
Hey guys,
I am doing some initial ground rounds with my Jab3300 engine and was noticing a popping noise in the headsets - while receiving ONLY. The popping noise is pretty bad. At first I thought is might have been the other aircraft's radio (flying in the pattern), but after tuning to a local ATIS I got the same popping sound. I am just trying to see if it might be something obvious, something that one of you might have experienced as well? It does not happen when the engine is not running. I am thinking that maybe I should start out by buying resistor plugs? I am NOT an electrical person at all... but I did try to wire per the Aeroelectric manual.
Any thoughts?
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
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Float Flyr
Joined: 19 Jul 2006 Posts: 2704 Location: Campbellton, Newfoundland
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Posted: Wed Oct 28, 2009 12:24 pm Post subject: Radio popping |
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That would be a good idea too!
Keep the list informed as to what you find out.
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Monday, October 26, 2009 12:49 AM
To: jabiruengine-list(at)matronics.com
Subject: Re: Radio popping
Noel, I appreciate all your help. I will check & double check all my wires. I guess if all else fails Bob knockoll's (sp) just lives 20 or so miles away... maybe he would look at it.
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Sunday, October 25, 2009 6:17:18 PM
Subject: RE: Radio popping
Because your interference speeds up with rpm it suggests a few things.
First of all because aircraft and towers you are talking to do not hear the interference it means the problem is not radio frequency (RF). This is great as it eliminates checking all the coax wires to your antennas.
A few other possibilities exist.
One can be a shield on a shielded wire that is grounded at both ends. Grounding the shield at both ends turns the shield from a shield to an inductor. Sort of like a guard turning to the other side….
Another possibility is the p leads for your magnetos should be shielded wires grounded at one end… preferably the firewall end.
I’m not sure if you are using an audio panel or not but if you are, all the interconnect wires going between the audio panel and the other items of your stack should be made using shielded wire grounded at the audio panel end. That goes for things like the mic and phone lines going to the jacks.
Once you have checked out those few items and made sure the case of your radio is also securely grounded if you still get the interference try resistor plugs or even resistor plug caps.
Keep us all informed on how things turn out for you.
One small piece of advice is there are literally hundreds of people around who have a lot of experience, not to mention equipment who are radio amateurs. It may not hurt to have one assist you in checking out your installation.
I also recommend to everyone to draw a block diagram of your installation as you do your check out… include things in your diagram such as wire colours or numbers and ground placements. Keep the diagram so you can refer to it if you ever want to change your installation or track down another problem.
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Saturday, October 24, 2009 12:51 AM
To: jabiruengine-list(at)matronics.com
Subject: Re: Radio popping
Noel,
Yes! It does increase with RPM. I was looking at my mag wires today and noticed that I made a pigtail from the shield material in the wire (side connected to engine) and grounded this to the firewall ground - all my grounds connect eventually. The panel ground leads to the firewall ground - which leads to the neg battery. I did not shield any of the wires to or from my com radio - the instructions did not mention it, anyways.. something to look at I guess.
Thanks!
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Friday, October 23, 2009 7:25:28 PM
Subject: RE: Radio popping
Michael:
If you find the popping frequency increases with rpm then your problem is most probably a bad ground in your audio section. Audio connecting lines should only be shield grounded at the feed end… never at both ends. The grounds do however need to be very clean. You will find, as I have, better than 90% of interference problems in aircraft are caused by poor grounding somewhere. The trick is to figure out where.
If you find the popping does not increase with throttle then the possibility is a heavy capacitor of sufficient voltage across the DC buss on your radios should cure it.
In the meantime the R582 engine ( you may have one) is a bit of an oddball in that it is recommended to use both resistor caps (5K Ohm) and 5K Ohm plugs.
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Thursday, October 22, 2009 6:04 PM
To: jabiruengine-list(at)matronics.com
Subject: Re: Radio popping
Noel,
I could not appreciate if the popping changes rate with RPM during the ground running operations. My attention was really focused on RPM, EGT, and CHTs at the time (trying to fine-tune an Aerocarb for first flight operation). At the time I was aggressively changing RPM but was on the local frequency - traffic transmissions were too short in nature to notice a change in popping. When no one is transmitting everything is normal.
I will listen to ATIS continuously on Friday while running the engine and report back.
Thanks!
Michael Hilderbrand
Derby, KS
www.kansasflying.com
From: Noelloveys <noelloveys(at)yahoo.ca>
To: jabiruengine-list(at)matronics.com
Sent: Thursday, October 22, 2009 11:48:06 AM
Subject: RE: Radio popping
This is Thursday morning so I’m taking a chanced you haven’t gotten any answers or even a fix yet.
First thing is, does the popping change rate with the rpm of the engine?
Noel
From: owner-jabiruengine-list-server(at)matronics.com [mailto:owner-jabiruengine-list-server(at)matronics.com] On Behalf Of Michael Hilderbrand
Sent: Monday, October 19, 2009 11:20 AM
To: jabiruengine-list(at)matronics.com
Subject: Radio popping
Hey guys,
I am doing some initial ground rounds with my Jab3300 engine and was noticing a popping noise in the headsets - while receiving ONLY. The popping noise is pretty bad. At first I thought is might have been the other aircraft's radio (flying in the pattern), but after tuning to a local ATIS I got the same popping sound. I am just trying to see if it might be something obvious, something that one of you might have experienced as well? It does not happen when the engine is not running. I am thinking that maybe I should start out by buying resistor plugs? I am NOT an electrical person at all... but I did try to wire per the Aeroelectric manual.
Any thoughts?
Michael Hilderbrand
Derby, Kansas
Http://www.kansasflying.com
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