How to build a (relatively) cheap intercom system

[totaljoint]

I've taken 4x4Pinz's idea of an intercom and adapted common e-bay (read: inexpensive!) components to work very well in a Pinz 712 for 8 people. If anyone is interested, here's what I've discovered:
portable units (battery driven, or plug in to 24 volt) are available widely on e-bay or Craig's list. Most units are for 2, some for 4 but get very expensive for 6 or more people.

The Sigtronics SP0-42 or Flightcom SXII are commonly found and work fine. Picked one up a SPO-42 for $36.00 on Craigs list. Runs 70 hours on 2- 9 volt batteries. A Flightcom SX II with expansion module runs about the same price, same features. Got that one for $40.00. Each one has room for 2 headsets on the main box and 2 on the expansion module= 4 total, but I needed 5 or someone was going to be left out.

I mounted the SXII behind the passenger seat, and it's expansion module about half way down the rear side tucked up against the side wall behind the folding seats (hid it all behind the e-trak).
Did the same with the Sigtronics on the other side behind the driver. You can cut off the extra cables which were intended to connect the units to the aircraft radios, unless you need them. I rolled mine up with a zip tie and saved them for potential resale value later.

The 2 independent systems are then connected together with two mini plug stereo plugs on a 6 foot leads (Radio Shack- $7.00/ea) and attached the line out jack from the SX II to the line in plug on the Sigtronics and vise versa. All wires hide nicely along the cab bulkhead. Now I have 8 live outlets (driver/front passenger and 6 in the back) which can talk to each other when both systems are turned on, no shouting. Best part, I can flip a switch and turn off the wife if necessary.
I can also plug an MP3 or cell phone into the system. It's portable, not hard wired and hidden. Running on the highway is quiet, we speak in normal volume and hear tunes as the same time. I won't comment on the legality of the headsets on the road.

Used headsets are available on e-bay for $25+ a piece, but found better prices on local Craigs list. Many flight schools are dumping lots of units right now.

I know this is not for every one, but took me a few trial and error's matching parts before I came up with the above.

My passengers get quite a kick out of this "feature" in the Pinzgauer on our way to the local micro-brewery!
Ed

[Skeej]

Wow! just starting some research and find this post- another reason whey this forum is so incredibly valuable. How much time would I have spent or wasted to generate this much info and bottomline good answer, here, otherwise.

(guess i have to hit that tip jar, again, vince!)

Doing a bit more, and here's a great source for the old-school approach, using bullet-proof military equivalent- VIC1 intercom that looks like a more expensive but more bulletproof approach.

My personal approach is I bot the Pinz for capability plus durability-backup vehicle to Mommy Style Family SUV- the Pinz for Dad to haul kids to desert, daily driver, go-to-home-depot- tow trailer once or twice a year to the dump, someday plus up to an expedition rig for longer runs.

Theres and theres a lot to be said for 70s era german/austrian design - lots of thought given to this purpose built vehicle and craftsmanship I am learning more about- so very happy.

But I am very much in favor of replacing anything in it that is obviously NOT safe, with latest tech that works, and especially at a bargain price for my budget- obvious fixes to critical fail items for kids- orig windshield, tires, seats in back replaced.

Next is anything that impacts safety, non-critical but "should do"- for a guy like me with hearing loss from military, this is a big one-

The highway noise is too much for long drives- and until I finish insulating everything and cough up $2500 for drive shaft

- for now it looks like headsets are the fix.

1. I've got a Bose QV2- thats adapted to using for handsfree with a Crutchfield adapter mic - tha I'll slip on off the left ear and wear a foam plug to get by the CA laws, and can play tunes from the cell.

A similar headset (they are cheaper but theres other full-ear, noise cancelling sets nearly as good even cheaper, that will happily keep the kids playing Nintendo all done the road and save my kids hearing, but thought the aviation versions were much more expensive-

so, THANKS ED-
this looks like a way to go, similar tech, similar connections.

A couple questions for Ed and anyone, and I'll share lots more detail as I find it, if this turns into a thread for common need:

1. Hows the aviation arrangement holding up to hard use?
Ed, looks like this is relatively new for you- any feedback?
Any others?

2. price tradeoffs with more heavy duty arrangements?
Coincidentally, another proof of when you start looking for something it drops in front of you- I was just thinking about this hard in last week- and today I found this in my email box-

http://groups.yahoo.com/group/mvintercom/

haven't compared prices, and am NOT an electical engineer- so theres a learning curve cost for me, that may be a benefit
for a radio hobbyist- but the reason I ask, is
two fold-

1. its the original gear, and its reportedly common, very well made, and for mil surplus you would think easy to get.

2. but the posts there and elsewhere seem to have trickled out in last two years- is there a paucity of VIC1s or are civilian sets so much more practical?

Curious if anyone has done the work to comment, thanks in advance, let me know by PM or public message if interested in more- I have some stuff saved already, going over with more, until I feel I have covered 90-9% % of what I can find online, then choose what works is my approach.

thanks again to anyone who made it to the end here....

[totaljoint]

I've had mine in for the last few weeks only. It has stood up to 6 teenage boys horsing around- fighting over who gets the last head set, yanking on cords, and two very wet dogs. I have kept them portable- to use in the boat this summer (For some reason I gravitate to loud vehicles!).

The Flightcom SXII is more svelt, fits behind the seats better and placement of the expansion box is more flexable than the Sigtronics, though the Sigtronics has slightly better sound quality.
I'm pulling out my Sigtronics (plastic box) and putting in another Flightcom unit (all metal). As far as toughness, both are FAA approved, they are pretty rugged units. Some of the salvaged ones for sale survived the crashes that took the rest of the plane.

As far as the combat version goes: I don't have experience with those systems, but by the photo it seems that they are much bulkier, and more buttons and switches, wires etc.. I can hook my aviation units up with cheap radio shack connectors, and take the whole thing out in 5 minutes if I want to. They are small enough to hide behind seats (front and back). I just adjust the volume and squelch and we're off.

I can't tell you how nice it is to cruise with these headsets. Even the wife likes to use them. No excess noise, just speaking in a low voice is all that is necessary, the cell phone (now hands free!) and stereo both hooked up and usable with no shouting or blasting of volume. Back passengers can hear the driver without having to turn around and shout.
My son enjoys pilot commentary:
"Attention passengers, those on the right side of the vehicle can see the Prius we just ran over"

They have made riding in the Pinz a different and very pleasant experience.
Ed

[4x4Pinz]

Check local laws before attempting to use an intercom system. Having said that here is my take on them.

I have been using the Avcomm system since early '05. I chose the Avcomm system as it carries a 3 year warranty something the Vic1 did not. I also figured that in the event I needed repairs it would be much easier to find some one willing to work on more modern equipment. To date I have done nothing but use the system with no repairs of any kind needed.
I went with a mounted control unit and six stations as at the time I only had one loud vehicle that was being used on the highway. Now with the addition of other vehicles portability became an issue. I purchased an expansion box, which runs on it own batteries or plugs into truck power. I can now take my intercom system to which ever vehicle I am in, mine or some one else's.
When I was a boy scout leader the Pinz was very popular and we used the intercom a lot. It is funny how it acted like an electronic leash. No one wanted to be left out of conversations so they all sat there nice and peaceful. As time has gone by we use the intercom less, either because I have found ways to quiet the truck and have been taking fewer passengers.
With my intercom system, and others I imagine, you can still hear the pinz noises just subdued considerably. I don't recommend using an intercom system until you have become aware of all the normal noises a pinz makes so that you can identify new and strange noises through the intercom.
The intercom system still remains one of my favorite non essential upgrades and makes highway travel much more enjoyable

[4x4Pinz]

here is a link to a picture of the non portable unit mounted in my 712's overhead console. You can see two of the intercom jacks to the rear of the overhead console and the controller in the front. The other jacks are mounted in the upper corners of the hard top in the rear passenger area.
http://real4x4forums.com/PinzgauerBBS/v ... t=intercom

[texas pinzgauer]

Does anyone have experience with battery powered headsets? I'm interested in something that enables better communications between me and my passenger...without yelling, using a grease board, sign language etc.

Perhaps something like bicycles might use on a tandem...

Ideas?

[Winter Beater]

Thanks everyone for the intercom idea. I bought an Aviation headset with DNR and a Audio input running off a pair of AA batteries .... it's incredible. I listen to my iPOD and do not get my hearing hammered by the engine + gears. Can still hear all the sounds but they are very low. Next I will install a Sigtronics intercom and keep a watchful eye on Craigslist for a passenger headset. Look forward to a long trip with nice tunes and a cigar.