VIC-1 Intercom Troubleshooting Assistance

[avlon01]

I installed my VIC-1 and am having some trouble.

I followed the TM and the system is wired per figure 4-4 (no radio).

All four stations are receiving power (they hiss when the power to the system is on).

The Commander station can speak into the system and I hear the voice on all 4 stations.

However, no audio is coming from the other three stations. I checked my cables and everything looks ok. Tested the headsets on the commander stations, and all headsets work there. As soon as I move them to a different station, I can only receive, not transmit.

Main control box is set to INT ONLY, CDR+CREW, installation switch set to INT ONLY. Crew stations are set to ALL or INT ONLY, does not seem to matter.

Suggestions?

 

[Wile E. Coyote]

Bizarre. If every outstation is doing the same thing, the AM-1780 is probably bad - though it's odd that the CDR station PTT works. When you took the headsets/ mic harnesses from the outstations and tried them on the CDR station - did you take the whole works including the Y cord - or just the headsets disconnected at the bail-out connector? 90% of the problems I have with those things is the stupid headsets and intermittent Y-cords. The earlier design had a bail-out connection that resembled the top of a 9 Volt battery - where the later ones had a barrel connection. I have a box full of the 9 volt style that are outright junk.

Make sure the cables going from the outstations to your AM-1780 are the correct VIC-1 cables and not the lookalike ones from the SINCGARS system which won't work, even though they'll screw in to the receptacles. The PTT line on the SINCGARS ones is swapped and won't trigger the AM-1780. The cables you need are the CX-4723s. If you have the CX-13292 instead - you're going to have problems. If the labels are missing, the correct cables will go directly into the plugs. The wrong cables have a 'bend' just before they enter the plug housing.

If you have the right cables, check each cable end for pushed-in/ recessed pins. Since you know your CDR station works - see if it still works when you plug it in the sockets used by the other C-2298 crew boxes each in turn.

Other than that...weird. I've had lots of bad everything with VIC-1 systems - really challenging when someone's put-together system has multiple problems, like the one in the Ferret at work, which had a bad 2298, a succession of three bad headsets, and one bad CX-4723. It was like some nightmarish troubleshooting test so you could graduate as a rad tech.

 

[avlon01]

Just to update for future searchers:

My AM-1780 was bad.

Borrowed a known working VIC-1 system - 2 cables, 2 headsets, two intercom boxes, 1 master control box.

Began replacing parts one at a time - starting with my control box. As soon as that was swapped out, my system worked fine.

 

[shawnshumvee]

Got a question concerning a Vic 1 unit. Everything seems to work good but i can hear this pulsing in the head sets. it doesn't mess with the clarity of the head sets its just there! Just wonding if anyone knows what it could be. i believe the sound is only there when Engine is running.
Thanks

 

[Augi]

Alternator whine.

 

[shawnshumvee]

Alternator whine.

Ok. Meaning what? Do I need some kind of filter or??
Thanks

 

[Augi]

Alternator whine is when electrical noise created by the alternator gets into the intercom system. There are methods you can try to filter it out. There are probably some commercial products out there you can buy and attach to the power in cable but I've never really looked into it.

I'm pretty sure there is some good filtering built into the radios that cleans up the intercom too because when I run without a radio in the rack I hear more whine in the intercom than when I have a radio installed.

Augi

 

[RJTM998]

Has any found a fix for altenator whine yet? I have tried everything and nothing has worked. In line filter, supplemental ground wire, tried different power cable including a NOS, different amplifier, etc nothing has worked. None of my other radio equipment has the whine just the VIC1.

Thoughts?

 

[RJTM998]

I figured out the alternator whine. When I mounted the crew boxes I screwed them into the wood on the tunnel but got into the actual metal floor and caused a ground loop. For those with this problem check your mounting points. Once I removed the screw that was touching the tunnel through the wood it went away. You might need to insulate your mounting points so no metal to metal contact.