VIC 1 in the M37

[ke6rwj]

so im a radio geek, frankly the m37 is an ACCESSORY to the RT524 i restored, the truck was purchased so i can put the radio in it..

anyway, i installed the VIC1, and im sure its not *exactly* oem, but hey it looks good...

here's what i did...

View attachment 240577

Mine has a hardtop on it, so i had this as an option, other options were on the seat frame front in the middle, or under the seat..


Anyone else put a vic 1 in the M37?
Where'd you put it?

incidentally i've also got some ham rigs going in there, ill be using the circuit by OPCOM documented here.

http://www.steelsoldiers.com/milita...roperly-interfacing-vic-1-vic-4-cb-radio.html

and because we all like to brag...

Before as purchased...
View attachment 240579

after an attack by krylon ruddy brown primer... i hate yellow...
View attachment 240580

 

[JDToumanian]

Is the M37 noisy enough to need it? Nice install.... You know Fair Radio has or had 2'6" CX-4723 cables, I've seen them elsewhere even shorter. Also, I've shortened them myself.... It's not fun, but I think it would look better than the coils of spare cable.

Jon

 

[ke6rwj]

Re: Noisy... hmmm "need it" . . well compared to the wife's Mercedes, oh yea its way loud, compared to a 5 ton, no not really. Its more about having access to the radio audio and an iPod input than anything else..

RE: Coils: yea i agree, this is a prototype, i got most of it from Steve Haney, and i wasn't sure where to put it all, so i just got 6' cables.. He has 1.5' ft cables i'm gonna get now that i know where its going...

BTW love Hesperia, was stationed at Irwin for 6 years...

Chris

 

[ke6rwj]

Update:

I built OPCOM little circuit as noted above, and it works great. Had to use some parts laying around to prototype it and just see if it worked as well as it looked.

I was able to interface 3 different radios. (I mean I tried it with three different radios, to make sure it was fine with all.)

- VHF EF Johnson Challenger 137-174 mHz (2 meter ham basically)
- UHF EF Johnson Challenger
- Cobra CB
- Uniden CB
- IPod

Excellent radio checks and good audio at road speeds. Since this was a prototype I'm rebuilding it, I'll post pictures soon.

 

[serial14]

Chris,

Since you seem to be the current tinkerer on the VIC-x systems I've got a question for you. I read this post as well as the referenced one from OPCOM. I like you, am a radio nut and my latest endeavor is integrating an LS-671 into my vehicle as a speaker for various ham & military radios.

I haven't found a concrete definition of what levels audio is at and who is responsible for driving them. In the schematics for the LS-671 it looks like everything is "line" level for both transmit and receive. But in OPCOM's post he mentions that the VIC-1 system( and presumably the LS-671 ) are just dump components and let the radio drive the audio and pass back low level mic audio. I've also seen similar comments on various websites. Can you confirm either way? Or will I become the expert on the LS-671 by virtue of playing around with it?

 

[ke6rwj]

Chris,

Since you seem to be the current tinkerer on the VIC-x systems I've got a question for you. I read this post as well as the referenced one from OPCOM. I like you, am a radio nut and my latest endeavor is integrating an LS-671 into my vehicle as a speaker for various ham & military radios.

I haven't found a concrete definition of what levels audio is at and who is responsible for driving them. In the schematics for the LS-671 it looks like everything is "line" level for both transmit and receive. But in OPCOM's post he mentions that the VIC-1 system( and presumably the LS-671 ) are just dump components and let the radio drive the audio and pass back low level mic audio. I've also seen similar comments on various websites. Can you confirm either way? Or will I become the expert on the LS-671 by virtue of playing around with it?

I'm not looking at the ls-671 schematic nor have I ever played with the vic4, but here is my experience with the vic1.

Based on the OPCOM schematic, there are no amplifiers in the circuit, and the audio levels from the radios (rt524 for example) are on a fixed level. Actually the radio outputs both fixed and variable sources, but it seems the fixed levels are best.

The key to making this sound good With non military radios is to match the impedance of the speakers and mics. In the case of the Vic 1, headsets need 150 ohm and the civi radio is 8 ohm, the transformer not only matches that, but provides necessary isolation from the different 12/24 volt systems. Mic is the same except that we are doing 600:600 ohm that is purely for isolation.

Ok having said that, there does not look to be any audio amps in there. The volume controls to the control boxes are simple variable resistors. If this were me I would wire it assuming that no amps are needed, make sure your impedances are matched, if htey are not matched, that could drive your levels off. You can't go wrong in using lots of isolation transformers to protect the circuits either.

What I'm considering is to have at least 5 radios
CHANNEL A
1 -RT524

CHANNEL B
1- R442

CHANNEL C
Junction Switch Box, that allows switching TX Audio, PTT between multiple radios, but allow RX from all, with a variable control.

1 - VHF ham,
1 - Uhf HAM / GMRS / FRS
1 - CB

(If this all goes well ill consider high power HF, but i am concerned about RF in the system as OPCOM has experienced)

I'll look at the schematic of the LS-671, i currently dont have any SINGARS stuff, but its on the list. I think i am at the limit of the little M37..

OH ! i could get a shelter! ..

Lets keep the updates coming, im interested in whats going on with this... im also putting together a "book" (word doc) that ill post that has all the tidbits and drawings..

 

[serial14]

Well, I've got a LS-671 on the way and plan on integrating it with several ham radios as well as my PRC119(RT1439). I'll let you guys know how it goes.

I'm aiming to integrate the LS-671 directly to a given radio, and potentially to the custom intercom I built for my deuce. However, its primary place will be in my daily driver. I'm sure I'll have to do something to the levels or at least want some isolation so I'll probably throw in some transformers or opamps.

Your list of radios is impressive. How do you plan on effectively using all those radios as a single operator? Will you ever have multiple radios on active channels at the same time? Will you have a dedicated radio for GMRS/FRS or just mod your UHF ham radio todo it? I can't decide if I want a separate radio for FRS/GMRS or just mod my existing ham radios. In my experience the commercial LMR radio audio sounds a TON better than ham radios, however they aren't the best when you just want to scan around on random freqs like ham radios. So I'm torn.

I'd imagine if I had that many radios, I'd make an audio panel that would let me mix all the radio sources, select the TX radio, and show some sort of indicator one which radio(s) are actively receiving audio. I've had a couple of ideas bouncing in my head, we'll see what pans out. I'm currently going through some projects to upgrade my antenna/radio infrastructure in both vehicles and base station. Once I get that done, we'll see what new gadgets I can think up.

 

[ke6rwj]

Well, I've got a LS-671 on the way and plan on integrating it with several ham radios as well as my PRC119(RT1439). I'll let you guys know how it goes.

I'm aiming to integrate the LS-671 directly to a given radio, and potentially to the custom intercom I built for my deuce. However, its primary place will be in my daily driver. I'm sure I'll have to do something to the levels or at least want some isolation so I'll probably throw in some transformers or opamps.

since the speaker is just a speaker, and your not gonna be using it with a mixed 12/24 volt setup, the transformers will be most useful to make sure impedances are correct. If its just a speaker and a mic, id probably just try to make an adaptor and just run it to the other radio...

Your list of radios is impressive. How do you plan on effectively using all those radios as a single operator?

Well its just like using multiple ham rigs in the car, i'll listen to all as required, talk on the one that happens to have the activity.

the trick here is to be able to have a "primary" for that activity. I figure that given that this hobby isnt all HAM's and not everyone will have a FRS/GMRS Radio, i needed to make sure i could have a talk option for anyone i happend to be with.

Will you ever have multiple radios on active channels at the same time?

Sure! I want to allow all the radios that are "on" to be receiving through the Vic1, so i could hear the audio from them all if required. But only one *should* be transmitting at the same time... (hmmm wow *that* would be cool to "simulcast" on all.... no... thats too much.... or is it )

Will you have a dedicated radio for GMRS/FRS or just mod your UHF ham radio todo it?

Since the GMRS/FRS freq pairs are standardized, and i do have a legal license on GMRS (one of the few who actually get one i've found out), i have a business band radio programmed to the channels, although i cant add tones on the fly, its never been an issue. now technically speaking the FCC never intended GMRS / FRS shared channels to interact, IE high power GMRS radios, interacting with low power FRS radios, they havent done anything to prevent it.

I can't decide if I want a separate radio for FRS/GMRS or just mod my existing ham radios. In my experience the commercial LMR radio audio sounds a TON better than ham radios, however they aren't the best when you just want to scan around on random freqs like ham radios. So I'm torn.

I have a ham radio that i've dialed the VFO to GMRS, but i dont want to do that here. The real issue isnt technical, its more about not being able to lock the m37, and needing to use radios that are more durable, HAM grade radios dont hold up under the abuse in the military vehicle... bouncing, temperature, water leakage, bumps, mud blah blah.. You can get older LMR radios all day long at hamfests and swaps.. if it gets trashed ..meh and if someone steals it, they dont make you cry like a new yaesu would.

I'd imagine if I had that many radios, I'd make an audio panel that would let me mix all the radio sources, select the TX radio, and show some sort of indicator one which radio(s) are actively receiving audio.

SHHH your giving away my ideas... I envision the exact thing... Ive hard wired the radios with a DB9 "pigtail" using the same pinout as my old APRS KPC3 TNC tracker.. (sorry if your not hammed up... its a data transmitter with GPS.. old school garmin GPS like thing) The idea is to have a common spec to interface the radio to the controller, so that i could swap out rigs, add as required, no soldering required.

Required Specs
- The controller will have 4 channels
- Each channel allows to turn on or off RX to the intercom
- There will be a slide, or dial selector to select which radio is current for TX by intercom
- integration should not prevent use of the attached radio mic, or otherwise prevent it from functioning if the system is off or the radio removed...(ie mic still works)
- each radio will have independent RX and TX level controls
- Pigtails need to be short to prevent feedback and RF issues.

USE CASE
in convoy its decided that the common channel will be #8 FRS and 23 CB... plus the hams will be on 51.00 with wideband FM mil rigs..

RT 524 on 51.00
FRS in channel 8, RX on
CB Channel 23, RX on, Squelch set closed
VIC 1 on "ALL"

VIC 1 is on "All" which allows "A" Transmit Radio RT524 for ham chat.
FRS is heard someone needs an update. move Vic1 to "C" rotate controller to FRS TX
TX on intercom to give details via FRS.
CB is heard, some one needs assistance, rotate Controller to CB TX give feed back..
Rotate VIC1 to "ALL" and continue ham chat...

now of course this is much easier with a co-pilot.. must be safe!

I've had a couple of ideas bouncing in my head, we'll see what pans out. I'm currently going through some projects to upgrade my antenna/radio infrastructure in both vehicles and base station. Once I get that done, we'll see what new gadgets I can think up.

I did nearly the exact same thing im doing here in Fire Trucks for years, its just a matter of putting some organization behind it all..

OH BTW about some practical items...

I have this thing about stuff looking authentic... the radios will be out of site, one is under the seat with a remote head, near the center of the roof, the others and the controller, are in the GLOVE BOX, shut the door and out of sight..

Antennas, two military grade on proper mounts mounted on the side, for RT524 and the R442 in the proper way.. the others.......... mag mounts in the bed... once the canvas is on, you'll never know they are there.



and for those who read this far and said... "he's a nut case" yes you are correct, but i redirect your attention to the fact that the M37 is an accessory to the RADIOS i love overkill..

 

[serial14]

Chris,

Thanks for the reply. It seems like great minds think a like. I was moving towards standardizing to the DB9 TNC pinout as well. Thats what I've done on my intercom already and its worked nicely. I'll probably do the same with my LS-671 interface and the upcoming multi radio adapter. What I don't know quite yet though is how much digital stuff I'll bring into the project. If I'll keep it simple with lots of knobs and analog circuits, or try and go fancy with microcontrollers and such.

I liked your comment about LMR radios VS ham radios. The ham radios are more expensive and not quite as rugged. Whereas the LMR radios are built to take a beating. With that thought in mind, I'm pretty sure I"ll get some LMR radios to dump in the deuce and daily driver preprogramed with some 70cm repeaters and the FRS/GMRS freqs. Then as I need a true ham radio I can add it in temporarily.

 

[ke6rwj]

UPDATE:

Built the first real prototype today..
View attachment 242467

The two round things are transformers, i didnt have any smaller ones, ill wait for the Digikey order to come in... the black box in the middle is a relay, two variable resistors on either side are for TX and RX levels...

The black cable goes to the AM-1780, the other Beige one with the chrome connector is a radio interface. As i stated in my earlier posts, i hard wire the radios with a DB9 pigtail to make swaps easy. I use the Kantronics KPC3 pinout.. (as a matter of fact i use a KPC3 to test the cables, before i use them on this..)

Here is the Ef Johnson 7183 Challenger 25 watt UHF with the pigtail installed.
View attachment 242468

A look inside of the 110 Watt VHF Challenger, this has the remote head, so there are twice the wires inside of it, but you get the point on the DB9 hookup...
View attachment 242469


Solder points I used:
MIC in off the microphone input
PTT off the mic input
Grounds, there are several
TX audio is AFTER the amp, but BEFORE the volume control, then i can turn down the volume to the external speaker and not affect the volume to the headsets, also i have a RX level control on the board, so no problem.. i just set it the same as the unsquelched RT524..
Power the unit is in the DB9 also, (pin7) this i use to power the controller also..


Next Steps...

1 - Get proper transformers
2 - Drop it in a nice little box
3 - reinstall all in the truck and run it for awhile..

More to follow...

 

[98taco3]

Are you still running on 24V? Im trying to figure out how to cut it down to 12v and still have enough juice to transmit. Ive got a FT8900 that i want to get mounted in the m37 when its done. I was thinking about the VIC1 too for an audio interface.

 

[ke6rwj]

Are you still running on 24V? Im trying to figure out how to cut it down to 12v and still have enough juice to transmit. Ive got a FT8900 that i want to get mounted in the m37 when its done. I was thinking about the VIC1 too for an audio interface.

Yes still 24 volt, I'm hooked to the first battery in the series, the one *closest* to the ground connection (that's very important!)..

You can get a 24-> 12 volt converter, but I'm not running one.

You should switch the batteries every now and then because you will end up putting one battery under more stress than the other.

The ham rigs that have packet interfaces built in, are easily integrated to the connection that I built.

I tested the following radios in the truck didn't have any issues with tx power or juice
FT5100 VHF/UHF dual bander
HTX202, radio shack 2 meter
FT-900 HF

I've got a doc somewhere that discusses the options researched by some public service group taking surplus military vehicles for use in the fire service. They discussed these options in detail.. I'll dig it up.

 

[ke6rwj]

There is a nice thread on this topic here --> http://www.steelsoldiers.com/deuce/50601-12-volt-radios-24-volt-m35a2-5.html

Looks like lots of experience there in this...

EDIT: found this product, looks quite good...
http://www.okoffroad.com/stuff-voltage-reducer.htm

 

[serial14]

I use the voltage reducers from OK Offroad and they work great. The only problem I had was with a loose crimp in the fues holder, but that was easily fixed.

They do have a low battery cut off I've noticed but don't know what its set at and how they've calibrated it compared to the "last start" point of the batteries. All I know is that you can't shove in 16V and expect to get out 12V.

 

[ke6rwj]

I called around a bit the overwhelming advice is that if your doing occasional use of the 12volt stuff, your gonna be fine tagging one battery, if you intend to really use anything on 12v you need to get the 24->12volt reducer.

to this point, my 12volt use has been limited since i havent yet gotten the intercom completely done...

Its clear the "right", "best" and "proper" way is to get the reducer... I'm happy to take the advice given on this one... so i'll be doing that..

I am concerned though about the ground path between the two sources now, i hope that this device doesn't do anything to that, because the circuit im using requires a solid ground between sources... (i cant imagine it would, but i'm still thinking about that.)

 

[serial14]

I just went out and did some tests on my 24->12V converter I got from OK Offroad( I have the biggest one ). The grounds are tied together, but the chassis/heatsink is isolated.

We use ours to drive a bunch of 12V gear, one of which is a LMR radio pushing out 50W of RF. We've had no problems at all with it.

 

[ke6rwj]

I just went out and did some tests on my 24->12V converter I got from OK Offroad( I have the biggest one ). The grounds are tied together, but the chassis/heatsink is isolated.

We use ours to drive a bunch of 12V gear, one of which is a LMR radio pushing out 50W of RF. We've had no problems at all with it.

thanks, this looks to be the best solution to the problem, this vhf radio pulls 27A at 12 volts, and 110 watts of RF. Its a hoss. the big one is the only choice, plus these things have a tendency to "grow".

 

[Boatcarpenter]

Perhaps one of you could answer a question so I don't have to start a new thread.
I acquired an R-442 to link with my RT-524. I have an AB-15/GR with 3 mast sections to use with it. What would be the minimum distance it should be mounted from my other antenna? Or doesn't it make to much difference. Can't seem to find the answer in any TM and I'm not a radiohead yet!
Thanks,
BC

 

[ke6rwj]

Perhaps one of you could answer a question so I don't have to start a new thread.
I acquired an R-442 to link with my RT-524. I have an AB-15/GR with 3 mast sections to use with it. What would be the minimum distance it should be mounted from my other antenna? Or doesn't it make to much difference. Can't seem to find the answer in any TM and I'm not a radiohead yet!
Thanks,
BC

If you make them 4-5 feet your fine.. Most military vehicles have standard locations, and jeeps and m37 have them on either side.. The only real concern is loading up
The R442 with a high power RT524 too close on the same channel..

Some purist Zealots will start arguing about load affects blah blah but it never mattered when I was a cav scout in the army..

Research some pics of your vehicle there will be several that show both mounted I'm sure... Btw what vehicle is it??

 

[Boatcarpenter]

Thanks ke6,
Vehicle is a Deuce. 524 antenna is mounted on the front of the bed on the passenger side so I can lower the dropside without disturbing the antenna. I guess I will put the other antenna on the other side front of the bed and it will be OK.
Thanks again,
BC