Guitarmaster Posted April 2, 2019 Report Share Posted April 2, 2019 Hopefully someone will have an idea... Garmin 430W. The squelch breaks constantly but only on 122.8. It has been to the shop and and set-up properly. This is the only frequency that is a problem. If I touch the radio, it gets better. Doesn't matter if the engines are on or off. Doesn't matter if the other radio equipment is on or off. it's driving me nuts and I hate that I can't figure it out. Quote Link to comment Share on other sites More sharing options...
EricJ Posted April 2, 2019 Report Share Posted April 2, 2019 Does it not matter where you are when it does it? If it is location dependent, there may be something radiating energy near that freq at that location. If it is location independent and the shop has already checked the radio out, your airplane may be radiating something spurious near that frequency or there is something in the harness somewhere near that freq. If you have a ham or other radio-geek friend, ask if they have a spectrum analyzer (they're cheap these days so more people are likely to have them), make a little sniffer antenna or stick a VHF antenna on it and see what you can see. You may be looking for a pretty low-power signal, but the idea is if there is any consistent energy in that channel that isn't elsewhere it may be responsible for that behavior. Most spectrum analyzers have hold functions that make this sort of thing reasonably easy, because it's a really common thing to do. Set the resolution bandwidth to about the channel bandwidth or less (25kHz). Another, maybe simpler, thing to try is to start pulling breakers and see if it goes away. If it stops when you pull the breaker on something, that may be what's causing the interference. 1 Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted April 2, 2019 Report Share Posted April 2, 2019 I assume your 2nd radio doesn’t have this problem?Tom Quote Link to comment Share on other sites More sharing options...
Andy95W Posted April 2, 2019 Report Share Posted April 2, 2019 Try adjusting the squelch on the GNS to a point where it stops. Test fly to ensure the radio still works acceptably at the new squelch level. I had to do this for the same reason because of 123.0, which is a very common UNICOM frequency where I am. Quote Link to comment Share on other sites More sharing options...
jaylw314 Posted April 2, 2019 Report Share Posted April 2, 2019 The squelch on the 430/530 can be adjusted from the COM SETUP page in configuration mode (hold the ENT button down while turning the unit on). The fact that it only happens on 122.8, though, makes me wonder like @EricJ if there's something nearby producing noise on that frequency. Quote Link to comment Share on other sites More sharing options...
Marauder Posted April 2, 2019 Report Share Posted April 2, 2019 Hopefully someone will have an idea... Garmin 430W. The squelch breaks constantly but only on 122.8. It has been to the shop and and set-up properly. This is the only frequency that is a problem. If I touch the radio, it gets better. Doesn't matter if the engines are on or off. Doesn't matter if the other radio equipment is on or off. it's driving me nuts and I hate that I can't figure it out. Could it because it is in a 310? Sorry low blow!The squelch setting is where I would look first. The touching thing could be some weird sort of grounding issue. Did the shop just play with settings or did they reseat it and look at the connections? I would also see if I could find another unit to slide in and see if it is tied to the radio.Sent from my iPad using Tapatalk Pro Quote Link to comment Share on other sites More sharing options...
Guitarmaster Posted April 3, 2019 Author Report Share Posted April 3, 2019 11 hours ago, Marauder said: The squelch setting is where I would look first. The touching thing could be some weird sort of grounding issue. Did the shop just play with settings or did they reseat it and look at the connections? I would also see if I could find another unit to slide in and see if it is tied to the radio. Tried changing the squelch on that freq, but to no avai. It gets a little better, but not much. Swapping with someone else's unit is a good idea. Quote Link to comment Share on other sites More sharing options...
Guitarmaster Posted April 3, 2019 Author Report Share Posted April 3, 2019 19 hours ago, Andy95W said: Try adjusting the squelch on the GNS to a point where it stops. Test fly to ensure the radio still works acceptably at the new squelch level. I had to do this for the same reason because of 123.0, which is a very common UNICOM frequency where I am. Tried many settings with the same or slightly better result. Even with the squelch all the way up, it still breaks repeatedly. . Quote Link to comment Share on other sites More sharing options...
Guitarmaster Posted April 3, 2019 Author Report Share Posted April 3, 2019 20 hours ago, ArtVandelay said: I assume your 2nd radio doesn’t have this problem? Tom Second radio (SL30) does not have the issue. Quote Link to comment Share on other sites More sharing options...
Guitarmaster Posted April 3, 2019 Author Report Share Posted April 3, 2019 20 hours ago, EricJ said: Does it not matter where you are when it does it? No, it is not location specific. Quote Link to comment Share on other sites More sharing options...
Guitarmaster Posted April 3, 2019 Author Report Share Posted April 3, 2019 12 hours ago, Marauder said: Could it because it is in a 310? Sorry low blow! Quote Link to comment Share on other sites More sharing options...
takair Posted April 3, 2019 Report Share Posted April 3, 2019 Cheap USB chargers can cause peculiar problems. You say you touch it and the problem goes away? Stinks of a ground problem. There are some ground points on the back of the rack that I found degrade over time. I stopped using them and use a more substantial airframe ground. It is possible your installer grounded to this same point. Might check the grounds.... 3 1 Quote Link to comment Share on other sites More sharing options...
Guitarmaster Posted April 3, 2019 Author Report Share Posted April 3, 2019 Got a chance to really mess with it on the way home today. It is in fact breaking squelch on both radios so I'm thinking it's definitely a ground problem.Sent from my Pixel 2 XL using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
Marauder Posted April 3, 2019 Report Share Posted April 3, 2019 Got a chance to really mess with it on the way home today. It is in fact breaking squelch on both radios so I'm thinking it's definitely a ground problem.Sent from my Pixel 2 XL using Tapatalk So it is a 310 problem. Sent from my iPhone using Tapatalk Pro Quote Link to comment Share on other sites More sharing options...
bradp Posted April 4, 2019 Report Share Posted April 4, 2019 I just got a digital vSWR that got highly rated by the Ham radio nerds. Helped me find that my painted over antenna was a 7. Took me all of 10 minutes. Would recommend checking antenna swr, antenna grounds, and then your radio grounds. Lot of alternator or ignition noise will cause RMI enough to break squelch as well. 2 Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted April 4, 2019 Report Share Posted April 4, 2019 Helped me find that my painted over antenna was a 7. Can you explain this statement? 7?Tom Quote Link to comment Share on other sites More sharing options...
bradp Posted April 4, 2019 Report Share Posted April 4, 2019 Most of the power was reflected back to the radio instead of out to the world. https://medium.com/hamph/swr-for-dummies-830f09855f95 Quote Link to comment Share on other sites More sharing options...
Marauder Posted April 4, 2019 Report Share Posted April 4, 2019 Most of the power was reflected back to the radio instead of out to the world. https://medium.com/hamph/swr-for-dummies-830f09855f95 This brings back good old memories of tuning my CB radio antenna. Good buddy. What’s your 10-20?Sent from my iPad using Tapatalk Pro 1 Quote Link to comment Share on other sites More sharing options...
bradp Posted April 4, 2019 Report Share Posted April 4, 2019 I recall getting an old CB my uncle had given my brother and I. We got the thing working and started making calls like we had seen in the movies. Some truckers in I-95 weren’t too appreciative and gave us some lessons in colorful language. 1 1 Quote Link to comment Share on other sites More sharing options...
EricJ Posted April 4, 2019 Report Share Posted April 4, 2019 4 hours ago, bradp said: Most of the power was reflected back to the radio instead of out to the world. https://medium.com/hamph/swr-for-dummies-830f09855f95 Did it get better after you stripped the paint or did you just replace the antenna or...? Quote Link to comment Share on other sites More sharing options...
bradp Posted April 4, 2019 Report Share Posted April 4, 2019 There was an orphan antenna - at some point in the plane’s history it has 3 coms based on my old audio panel. I just have the two radios off the two good antennas now - a top and bottom. Quote Link to comment Share on other sites More sharing options...
Gary0747 Posted April 7, 2019 Report Share Posted April 7, 2019 Do you have an old DME? It is higher frequency so it can’t be a harmonic but those things have been know to emit spurious RF. I had one in the past that would plot on my storm scope when tuned to a specific VOR. Make sure it is turned off when trouble shooting. Quote Link to comment Share on other sites More sharing options...
Guitarmaster Posted May 13, 2019 Author Report Share Posted May 13, 2019 Okay, so I found the source of the problem flying home last night. It's the Insight G4 engine monitor believe it or not. The next question is, why is it happening.The saga continues.....Sent from my Pixel 2 XL using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 13, 2019 Report Share Posted May 13, 2019 Matt, Check In with Marauder’s writing on the subject... As it was his JPI that was doing it... Might be a similar situation and fix... Best regards, -a- 2 Quote Link to comment Share on other sites More sharing options...
Andy95W Posted May 13, 2019 Report Share Posted May 13, 2019 Good memory, Anthony. Hopefully Chris @Marauder will re-post his solution. 1 Quote Link to comment Share on other sites More sharing options...
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