The coax shield and wires connected to the sleeves of the audio jacks are grounded to Van's control board only, not to the airframe. According to Van's SkyView Prior schematic, the coax shield and Wht/Grn wires are connected to Options pin 37 (Gnd); and the Wht/Blk wires are connected to Autopilot pin 12 (Gnd). Microphone jacks and music input jacks are the most vulnerable to noise because those inputs get amplified. Ground them at the control board only, not to the airframe.
Hi Joe,
I shall confirm jacks are isolated and determine which Dsub pins 2 and 20 are located....Thank you for the clues..Doug
Intercom pins 18 and 19 have audio output to the intercom from more than one source, i.e., EFIS & music & whatever.
Fuselage D-Sub pins 2 & 20 only carry audio input from the music jack.
No intercom input??? What connector did you remove pins 2 & 20 from?
Since you mentioned needle, I assume that you have an analog meter, which is fine. It needs to be be set to measure resistance. The meter might have "R" for resistance, or the ohm symbol Ω. Test the meter to be sure it is working. The needle should swing from one side to the other when the meter leads are shorted together. Connect one of the meter leads to bare airframe metal and the other lead to each jack, one at a time. The needle should not move when the jacks are touched.
The headsets and D-Sub connectors "FUSELAGE" and "OPTIONS" should be unplugged during this test.
Doug, I am not sure if I understand you correctly. You said that crossed probes reads open. When ohmmeter probes are touching each other, the display should read close to zero ohms, in other words, closed, not open.
With headsets and fuselage and options plugs disconnected, and the meter connected between airframe and headset jacks, the meter should read infinity aka open.
If the headset jacks are confirmed to be insulated from the airframe, try disconnecting the GPS D-Sub connector from the AV-50000A to see if that eliminates the noise.
If the headset jacks are confirmed to be insulated from the airframe, try disconnecting the GPS D-Sub connector from the AV-50000A to see if that eliminates the noise.
Do one thing at a time so that you will know what the problem is.
A ground loop isolator between the GPS and AV-50000A might help.
Doug, evidently someone else built your plane. Maybe the toroid was an attempt by the previous owner to eliminate the noise. Buy a ground loop isolator and install it in series with the GPS audio.
I suppose that I wasted your time checking to see if the headset jacks had continuity to the airframe. That test is only valid if ALL of the jacks have insulating washers. Even if only one jack is touching the airframe, the ohmmeter will show continuity to every jack since their ground wires are all connected together. If fixing the GPS ground loop does not completely eliminate the noise, then insulating every audio jack from the airframe might be helpful.
I did not realize that the transponder had audio altitude reporting (post #70).
I think I would cosider the Garmin Aera 660. The footprint is almost the same.Concur, if the GLI works I'll keep her. If not then out she comes. Then what to do with the bigO hole in the panel? Just short of replacing the panel I might try to install an airgizmo in place of the 496 for my Aera 560 and not hard wire it in. I think garmin still supports it? How's that sound.
OK Driftdown!
Do you know if the 660 uses a remote antenna like the x96's, is there a plug-in for one somewhere or is the antenna just self contained?
The GPS x96 was sold with the D-180 system. The reason Van's does not sell a portable GPS with the RV-12 avionics anymore is because it is not needed. The SkyView system has its own GPS. This issue has nothing to do with ipads.
I would not let the possibility of problems deter me from installing desired avionics. Most problems can be solved.
The alternator and strobe noise heard in the headsets is due to the audio output of the GPS, not due to the navigation function. I do not know if other brands or models of GPS have ground loop noise issues.
Actually I have found the 496 audio to be rather annoying. Especially when it yells, "Terrain, terrain, TERRAIN, pull up, pull up, PULL UP.
An option is to leave the audio cable disconnected.
Check the transponder antenna mounting to be sure it is grounded.
Check the voltage regulator case ground and battery negative ground. There should not be any paint on the sheet metal that could interfere with current flow.
Joe,Mauritz,
The SL40 has a built-in intercom. Perhaps that function was turned on before adjusting the sidetone, and now the SL40 intercom function is shut off.
Although I have never tried it, the Flightcom 403 intercom should work with the radio shut off. So with the radio shut off, can you still hear yourself talk? Can the passenger hear himself talk? I tell my passengers to keep the microphone close enough to kiss. And if they can not hear themselves talk, then neither can I.
Does the intercom break squelch when the knob is turned clockwise?
Is the intercom switch up in the ICS position?
Are both headsets stereo?
Have you tried other headsets?
The intercom works best when both headsets are the same brand and model.
I would like to raise the volume of the EFIS alerts (a tad), my SV setting is at 100%. I have the avionics bay open, should I use my iPhone aux music to test EFIS pot adjustments checking for increased volume as I turn the pot or are adjustments more problematic than just turning the pot screws in or out? Thank you!We were chasing this very issue for the last several weeks (Skyview/Flightcom 403/SL40).
First I tried pulling pins 18 & 19 from the intercom connector, which worked besutifully until it became evident that this also disabled all of the Dynon aural alerts.
I spent a bit of time looking through wiring diagrams until I stumbled upon the page describing the initial Dynon audio setup. Eureka! Spent an hour or so fine tuning the EFIS (L) and EFIS (R) pots on the side of the AV5000, and I'm quite happy with the result.
The book actually has you practice adjusting the pots using an iPod connected to the aux input to get a feel for adjusting them before adjusting the EFIS L&R pots.
The manual specifically mentions the noise generated but the Skyview, and how we need to turn down the EFIS audio pots on the AV5000 until we can hear the aural alerts, but not the background noise. The pots have a 25 turn range, so finding the sweet spot took some time. Eventually, I gave up and turned the pots fully CW until they bottomed, and worked them out 1 turn at a time until I had audio again. The rest of the time was spent fine tuning them so I had the same volume in each ear (I had to flip a dip switch to get stereo audio in my headset. Once done, I went back to mono, as I use the headset in other airplanes that aren't wired for stereo audio).
Getting at the pots is a bit of a challenge,and I had to pull the glare shield to gain access. They're located on the right side of the AV5000. One could pull the screen instead, but you'd have to reconnect it every time to check the audio levels. I had to adjust the pots by feel, but it's doable, if not necessarily easy.
Now I can fine tune the Dynon alerts in the software and have essentially no background noise in the headsets.
Hope this helps someone.