Tell me about -- GTN Squelch Issues...

[Piloto]

Looks like the JPI is leaking some of the digital pulses inside into the wire. Typically this is prevented by a 0.01uF smt capacitor at the JPI PCB/wire connection to ground. It could be that the capacitor is missing on the PCB. Routine factory testing does not check for this.

José

[Marauder]

Another update. JPI tech support just called and told me they are sending out a filtering wire with a clamp to attach to my remote indicator wire. When I get it, I will post so everyone can see what it is and where it goes.

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[rbridges]

Boy, I have to say that I'm relieved for you.  I know that was/is a frustrating road to go down.

[Marauder]

Another update. Here is what JPI sent.

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[N601RX]

Those are wrap around chokes and will help. I've done a lot of EMI testing at work on products we design that have wires going into them. In an isolation room we sweep the noise from a few mhz to 1 ghz usually. I've found that the length of the external wire will usually determine the frequency that the noise causes the problem on. If the wire length is some fractional wavelength of the noise frequency it is very likely to pick it up or in your case possibly broadcast the noise.

[Marauder]

Those are wrap around chokes and will help. I've done a lot of EMI testing at work on products we design that have wires going into them. In an isolation room we sweep the noise from a few mhz to 1 ghz usually. I've found that the length of the external wire will usually determine the frequency that the noise causes the problem on. If the wire length is some fractional wavelength of the noise frequency it is very likely to pick it up or in your case possibly broadcast the noise.

That is good to hear! Is the wire run through them? It looks like there is 12 inches of wire between the indicator and the unit. Do I just snap it on the wire?

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[N601RX]

Normally you would wrap the wire through them several times then snap it shut. Put them as close to the Jpi box as possible.

[Marauder]

Normally you would wrap the wire through them several times then snap it shut. Put them as close to the Jpi box as possible.

Thanks for the information. I could ask one of the electrical engineers at work tomorrow, but it will be an hour long process as they explain the theory behind them before telling me how to use it.

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[rbridges]

It seems like JPI would have given you some advice or instruction about where to place them.  Good luck.  Hopefully this will solve the problem.

[Marauder]

It seems like JPI would have given you some advice or instruction about where to place them. Good luck. Hopefully this will solve the problem.

They did. "Put it on the wire"

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[Marauder]

Another update. JPI has returned the unit for the MP firmware update and the ferrite clamp has been installed per their instruction. Here is what it looks like:

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[Marauder]

Very happy for you that you finally identified your issue. Happy resolution!!

And you thought it was Garmin!

Chris, Chris, Chris!!

When are you going to learn Chris!!??

You see? No need to fear the big bad gorilla!! He is really not that bad after all!!

 

Man -- how did I miss this reply? I guess if Garmin built a $10,000 box with a little better RF shielding, I wouldn't need to worry about a  $3,000 box causing interference. 

[PTK]

Man -- how did I miss this reply? I guess if Garmin built a $10,000 box with a little better RF shielding, I wouldn't need to worry about a $3,000 box causing interference.

JPI had a little slip up. They should know better and hopefully they'll include the little 50¢ filter going forward on their units.

[mike_elliott]

JPI had a little slip up. They should know better and hopefully they'll include the little 50¢ filter going forward on their units.

lesson learned...Garmin products wont work correctly in less than an absolutely lab perfect environment, like they are tested in. No room for field variables. 

[PTK]

lesson learned...Garmin products wont work correctly in less than an absolutely lab perfect environment, like they are tested in. No room for field variables.

Similarly JPI will work perfectly on the bench. We'll never know what it'll interfere with in the airplane until installed. No room for variables.

[Marauder]

Similarly JPI will work perfectly on the bench. We'll never know what it'll interfere with in the airplane until installed. No room for variables.

Another update. The JPI provided ferrite clamp (for free Peter) fixed the interference issue with the GTN. That said, I noticed that I was picking up interference from both the JPI and the Garmin GTN. Not sure what the tolerance is for noisy RF interference, but both have it coming from their displays.

http://youtu.be/xOBA-FOu944

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[ArtVandelay]

Man -- how did I miss this reply? I guess if Garmin built a $10,000 box with a little better RF shielding, I wouldn't need to worry about a $3,000 box causing interference.

It's the responsibility of electronic products to control their RF emissions, expecting a radio receiver to be shielded against radio frequencies seems asking a bit much.

[Marauder]

It's the responsibility of electronic products to control their RF emissions, expecting a radio receiver to be shielded against radio frequencies seems asking a bit much.

There are standards of what can be emitted. When I made the last video I had an electrical engineer with me who specializes in our regulatory compliance for DoC, UL, CE, blah, blah, blah. I brought him along in case the ferrite didn't work. He was a bit surprised that the standards allowed any of these displays to emit what I picked up.

The main thing is the open squelch issue seems to be resolved.

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[jlunseth]

I have a 430AW (16 watt transmitter) and a 36 year old King in my panel. I tend to use the Garmin most of the time because it is nearer to me and the designated comm 1. However, the old King is a better radio despite the supposedly superpowerful transmitter in the Garmin that I paid about 3 grand for. My pretty much regular practice is to use the Garmin for transmit and receive, but also have the King tuned in and the receive function switched on, on the audio panel. If I lose ATC the first thing I do is switch to the King and most of the time that cures it.