PS Engineering PM1200 to SV-COM and HDX

[PHILCAM]

Does anyone have a wiring diagram for a PM 1200 to SV-COM and HDX?

 

[Rhino]

Which SV-COM?

 

[PHILCAM]

Which SV-COM?

the 425

 

[Rhino]

Is the part number of your PM1200 11961 or 11960-EXP?

 

[Rhino]

This is adapted from the HDX Wiring Diagram. I don't have a pinout diagram for the X25, but everything I see seems to indicate it's the same as the T8/T25, so this diagram assumes that to be the case.

This is for the PM 1200, part number 11961, without the expansion module. It will be slightly different if you have part number 11960-EXP, with the expansion module.

The PM1200 does not have aux audio inputs, so I have alert audio from the HDX routed to the music input. Be aware, this will cause your alert audio to mute when radio transmissions are being received or when the intercom is being used. That's a built in feature on the 1200 that can't be changed. Alerts will still be displayed on the HDX, regardless of muting.

There is a 10 ohm resistor added between the HDX and the 1200, to avoid loading and possibly damaging the HDX, as per the 1200 installation manual.

This is only an interconnect diagram between these boxes. It does not include other connections, such as power, PTT switches and headphone jacks. You'll find those in the respective installation manuals.

I make no guarantees, and invite others to correct any mistakes I might have made.

 

[Rhino]

Just saw you changed your last reply from X25 to 425. Let me go back and see if that changes anything.

 

[Rhino]

Yes, that changes things. I've deleted the diagram I posted earlier, and will redraw it for the 425.

 

[Rhino]

Okay, pin numbers changed for the 425. Also a different connector type (DSUB-15). Everything else remains the same.

EDIT: Found a mistake. Stand by.

 

[Rhino]

Glad I looked again. There were a few mistakes. Hopefully this does the trick. It's prettier too.

 

[PHILCAM]

Amazing, thank you!! This is what I had come up with also, I needed to double check my work, as I'm trouble shooting some issues now. I think my problem is I misunderstood that the PS Engineering must have the aux jacks on pins 4 & 17 and on 25 & 13. I tried to wire it without jack, just direct input from the SV COM. Also, from the HDX, I tied pins 13 & 31 together and instead of going to the music input (pin 20) like you did, I have them going to pin 25.

 

[Rhino]

Those pins aren't really for your headphones. Pins 4 & 17 are radio audio coming out of the 425 to the intercom (incoming transmission). Pins 25 & 13 are the microphone audio from the intercom to the radio (outgoing transmission). PS Engineering makes it a bit confusing because they're offering you the option of using them for an auxiliary headphone input to use a radio without the intercom, but they list it as required for a 'complete' installation. However, an aux jack is only used to aid in troubleshooting, or as a bypass in the event the intercom fails. It really depends on how complex you want your panel to be. Most simple sport aircraft won't have an aux jack, but it's up to you. The pilot headphone jack is actually pins 18, 23, 24 and 13, and the copilots headphone jack is pins 19, 22, 21 and 10. However, those pins are for the 11961. The 11960 uses slightly different pins, and the 11960-EXP with the expansion module uses an entirely different set of pins. You never actually identified which model you have, so I made the drawing for the 11961 by default. Speak up if you need the pinout for one of the other models.

 

[Rhino]

This is for the 11960. The only difference in the interconnect is pin 7. Other stuff (other than the interconnect of these boxes) may be a bit different too.

 

[PHILCAM]

I have the 11960 and the X25, but, the wiring from the SV-COM-425 to the SV-COM-PANEL is spelled out straight forward in the Dynon install manual, so I didn't need that. I was just double checking the SV-COM-425 to PM1200.

When you say "those pins aren't really for your headphones" are you talking about the PM1200 pins 4&7 (aux headphone jack) and pins 13&25 (aux mic jack? If so, yes, I know that and I'm trying to get around installing them, and I'm curious if without them might be the cause of my problem. I'd like to use those pins only for the input from the SV-COM-425 (like in your drawing).

 

[Rhino]

Yes. If you aren't installing an aux jack, pins 4, 17, 12, 25 and 13 should only go to the radio, except that 4 and 13 should also be connected to your shield ground. Not having those pins connected to a jack should not be causing any problems. As a general rule, PS Engineering recommends you only ground your shielding at the intercom end of the cable.

I also forgot to add it to the diagram, but there should be a ten ohm series resistor in the line out of pin 20 to the Skyview.

EDIT: Added the resistor to the diagrams.

 

[Rhino]

Not sure if it helps, but this is what the diagram in the 1200 install manual would look like without the aux jack.

 

[Rhino]

.....Also, from the HDX, I tied pins 13 & 31 together and instead of going to the music input (pin 20) like you did, I have them going to pin 25.

I should have noticed this sooner, but that isn't right. Pin 25 on the 1200 is supposed to be audio going out to the radio from the intercom, not audio being input to the intercom from somewhere else. Is it also connected to the radio? If pins 13 and 31 on the Skyview are connected to both pin 25 on the 1200 and Pin 1 on the radio, you might transmit alert audio out over your radio when you key your mic. You'll also never hear alert audio, and you could potentially damage the intercom or radio. Pins 13 and 31 on the Skyview are outputs, and they need to go to an input on your intercom, which is why I tied them to pin 20.

If you're trying to tie alert audio from the Skyview directly into the pilot's headphones, you'd need pin 18 for that. Be wary of impedance mismatches or loading by tying two audio sources together though (I'd definitely use the 10 ohm resistor).

If you're trying to tie alert audio from the Skyview into the audio line from the radio to make it heard both the pilot's and copilot's headphones, that would be pin 17. I'm not sure how the radio would react to that though, and you still have to be wary of impedance mismatches or loading.

I'm not saying tying in this audio won't work with your equipment. The intercom just isn't designed for it, so it might be a risk. Audio can be real fickle sometimes. If you really, really, need an aux input, maybe you should consider a different intercom or a com panel. Or, if you only have one radio, an intercom designed for two will provide an extra radio audio input without having an aux input. Alternatively, you could get an audio mixer. That gives you much of the functionality of a com panel. It's cheaper than a com panel, but it requires effort to design and integrate into your system.

 

[PHILCAM]

My mistake, yes, I meant pin 17, not 25. I talked to PS Engineering about it and they recommended the music input.

 

[Rhino]

This is the whole thing in pdf format.