9th Jun 2012, 16:12
My 2-seat blind intercom amplifier, a firewall-mounted black box going by the name of AM-MU-2A, appears to be harbouring a colony of gremlins. As they seem to belong to a rare endangered subspecies, I decided to transplant the whole device back to the wild, and install a newer panel-mounted 4-seat equivalent. Essentially, it boils down to two options: either get an amplifier unit alone and interface it to the existing KMA24, or get a new audio panel with a built-in amplifier (and a marker beacon receiver, to replicate KMA24's functionality). I am trying to keep the costs to a reasonable minimum, but it has to be a panel-mounted unit for certified aircraft, and ideally it should have coarse volume, mic gain and VOX threshold field-adjustable for each headset separately. Could anyone recommend such a device?
9th Jun 2012, 16:59
Whilst there are many certified panel mount intercoms, none offer independent volume, squelch and mic gain for each position. Simple units such as the Sigtronics SPA400 are basic and will just cope with 4 seats but have no split front/rear or pilot isolate features. Best unit I know of is the AA80/82 from NAT ( now Cobham), but PS Engineering also make a good unit in the PM1000. Ideally you would ditch the KMA24 and fit a Garmin GMA340, GMA350 (with neat surround sound) or PS Engineering PMA8000 audio panel with all of the multi-mode intercom features built-in.
9th Jun 2012, 17:11
I just fitted a PS PPM1000 in my certified aircraft - awsome! I'm realy deighted with it. I flew with a small kid in the back last weekend; split mode front and back intercom allowed me to concentrate and talk to the front seat while the kid in the back chatted away to her Grandad in the back.
It has individual volume and squelch for the two front seats.
I'd recommend it.
10th Jun 2012, 05:06
PS Engineering stuff isn't the cheapest, but the quality and reliability is excellent. I have a 4 place set up in a 2 seat aircraft, but I use one of the extra channels for Garmin Traffic and GPS alerts, which also works very well.
10th Jun 2012, 08:41
PS Engineering - I agree.
A proper intercom drives all headsets separately, which does away with most of the problems one has with the bodged audio systems in most GA aircraft.
It's no rocket science (very basic audio electronics) but for some reason not many people have designed stuff that works.
10th Jun 2012, 08:46
Well, then, given such a consensus, PS Engineering may it be, thanks guys!
10th Jun 2012, 09:19
Make sure you get one with an extra input or two, so you can connect up e.g. the TAWS warning messages from a Garmin 496 into it, under the AUX button. I have the details if you need it - email me. Garmin UK didn't want to co-operate on it.
A and C
10th Jun 2012, 11:34
Having had the PS1000 (with the passenger expansion units so the pax have control of their own audio levels) I can't recomend PS engineering highly enough, the kit has worked faultlessly for sixteen years.
The Garmin GMA340 ( that wigglyamp's outfit fitted ) has been working well in another of my aircraft for the past four years with good customer feedback.
My other two aircraft have the sigtronics unit, not a bad bit of kit and very good for a two seat aircraft but I would not recomend it for any more than two places, in a four seat aircraft it is out of its depth!
On reflection I would only buy a PS engineering system for my personal aircraft as they seem to produce the best all round product with the Garmin GMA340 coming a very close second and probably better for a rental aircraft simply because they are now so common that most pilots know how to use them. The result of this is I don't end up chasing reported snags that are just "pilot finger trouble".