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By Baldrick
FLYER Club Member  FLYER Club Member
#1682985
Hi, We’ve recently had a problem with a noisy squelch on our 430 which seems to have occurred since changing to 8.33 MHz separation.
It’s definitely the Garmin as the rx illuminates when the squelch breaks.
Has anyone else experienced a similar problem and if so how did you fix it?

Thanks,

Baldrick
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By T67M
FLYER Club Member  FLYER Club Member
#1682989
What sort of squelch issue? Not lifting at all? Not lifting quickly enough? Not squelching at all? Not squelching quickly enough? Something else?

I've certainly noticed that a large number of aircraft and ground stations now "fade in" over a couple of seconds at the beginning of a transmission rather than starting cleanly since we moved to 8.33, ie the squelch is lifting too slowly. I now consciously wait a second after pressing the button to compensate.
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By T67M
FLYER Club Member  FLYER Club Member
#1683039
Almost continuously implies the squelch setting (SQ833 and/or SQ250) in the setup menu needs adjusting slightly - see page 5-15 of the installation manual.

Absolutely continuously implies that the volume knob has been "clicked", which lifts the squelch until the knob is clicked again.
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By Baldrick
FLYER Club Member  FLYER Club Member
#1683045
Thanks T67M,

I came to the same conclusion, but I can’t get to the aircraft again until Friday.
Also a bit wary of going into the setup menu, but as they say faint heart never won a pig.

Thanks shay,

Baldrick.
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By Baldrick
FLYER Club Member  FLYER Club Member
#1684398
T67M wrote:Almost continuously implies the squelch setting (SQ833 and/or SQ250) in the setup menu needs adjusting slightly - see page 5-15 of the installation manual.

Absolutely continuously implies that the volume knob has been "clicked", which lifts the squelch until the knob is clicked again.


All combinations of avionics ave been tried to eliminate the problem to no avail, so I accessed the Com Setup page, the SQ250 was set to 43 and the SQ833 was set to 14.

Twice I adjusted the SQ833 but was unable to store the changes. The ‘Store Calibration’ field could not be selected.

The next option is to send the box off for repair the quote for which was £1100. Unless anyone knows how to store the setting?
By johnm
FLYER Club Member  FLYER Club Member
#1684400
@baldrick have you asked Alec Vincent at RGV for advice, if not I would recommend that you do.
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By stevelup
FLYER Club Member  FLYER Club Member
#1685611
Have you eliminated every possible rogue source of RF noise in the aircraft? Very specifically made sure there are no USB chargers are similar left plugged in? Tried it with absolutely every other device turned off except the GNS?
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By Baldrick
FLYER Club Member  FLYER Club Member
#1685619
After a chat with Alec Vincent at RGV I was able to adjust the 8.33 MHz squelch setting. This got rid of the noise, however when I switched the landing lamp on the noise reappeared. We fitted an LED replacement lamp nearly 2 years ago and the squelch problem has only recently occurred. I’ll bench test it next week it’s a Teledyne Alphabeam. I’ve emailed the manufacturer, but unsurprisingly they haven’t replied.
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By stevelup
FLYER Club Member  FLYER Club Member
#1685620
It’s almost certainly a switch mode power supply somewhere, and there will indeed be one in your LED landing light.

Could be a ground issue as well - the landing light may be within spec.
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By T67M
FLYER Club Member  FLYER Club Member
#1685630
The squelch level should really be adjusted with every other device switched on. If you set it with the landing light off, you may not have set it to a high enough value.
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By c177_Alex
#1937178
Hi,
I also have a squelch issue on my GNS 430 non WAAS. When I setup a 8.33 Frequency in Standby squelch is not opening anymore. If I select a 25k Freqency in standby it works. So in 8.33 spacing mode squelch affects what I select in Standby. I made tests today. If I select our Airport Info Frequency of 133.880 I can hear it with an (in Setup Mode) selected 8.33 Squelch above 10. And above 25 i cannot hear the info in my Hangar, so squelch dozen´t open anymore. If I change spacing to 25kHz in the line below I can setup what I want in both settings. Squelch never open and squelch never closes.

Anybody ever expierienced something like that?

My settings at the moment are on the 3 adjustable Frequencies around 34/13. This is average of our 4 Flying club planes.

Alexander