PRC68 / PRC128 Vehicle mount Help?

[Artillerydan]

Hello,

Trying to understand the set up for the vehicle mount for the PRC68 & PRC128 radios. I have the PR68 ( looking for a PRC128 ), and the mount, OF185. What else do I need? Cables, power supply, ???? Thanks!

 

[mutt1966]

Google OF-185 PRC68.com will give you all that info.......Scott O&O

 

[ke6rwj]

Hello,

Trying to understand the set up for the vehicle mount for the PRC68 & PRC128 radios. I have the PR68 ( looking for a PRC128 ), and the mount, OF185. What else do I need? Cables, power supply, ???? Thanks!

really just power and the antenna... did you get the speaker with it? the antenna will be the critical thing... if you using the radio with no amp, then the normal antennas like AS-1759 are like transmitting into a wet loaf of bread...

 

[Artillerydan]

I have been on the PRC68.com site but I am not understanding how it goes together & what can and cannot be used together. There are a lot of "I am going to try" and "this works" type of statements on the page.

I did not get a speaker.

First off I know more than most about military radios but I do not understand this stuff like you guys do. I do not get which of these antennas can or cannot go with what radio or this one works with that one better.

In the first picture on the PRC68 site http://www.prc68.com/I/OF185.shtml - I have the radio & the related mount & housing (which I assume is the OF-185). Now the part on top is an amp? and how does it plug into the radio or the OF-185? There are no pictures of the back side.

So I gather a standard LS-454 will not work with this?

I am familiar with the RT68 series and the RT524 & related but some of the newer stuff I just don't get how it goes together AB15s and MX6707s... Easy stuff. The older "main stream" stuff was very simple. The biggest thing is, I don't want to just buy some of these items when I really do not know if they go together for sure.

Murphy has a "power amp module mousing for the PRC-68 thru 136" I would assume this is the right amp but it does not look like the one in the picture on the PRC68 site. Then cables for interconnection...... HELP!!

Anyway..... In recap I assume I need an amp, the correct antenna/matching unit, speaker (since ls454 will not work), and power cables. Any help on part numbers or who has this stuff.

I really appreciate your help on this.

 

[ke6rwj]

I have been on the PRC68.com site but I am not understanding how it goes together & what can and cannot be used together. There are a lot of "I am going to try" and "this works" type of statements on the page.

Brooke Clarks Website is great he uses it for research, so there is lots of theory there, but still excellent..

I did not get a speaker.

OK we need to address this..

First off I know more than most about military radios but I do not understand this stuff like you guys do. I do not get which of these antennas can or cannot go with what radio or this one works with that one better.

no worries we can help..

In the first picture on the PRC68 site http://www.prc68.com/I/OF185.shtml - I have the radio & the related mount & housing (which I assume is the OF-185). Now the part on top is an amp? and how does it plug into the radio or the OF-185? There are no pictures of the back side.

the top item on the picture on PRC68.com is an amp. The bottom part, is the power supply and Audio amplifier

So I gather a standard LS-454 will not work with this?

not with the default plug

I am familiar with the RT68 series and the RT524 & related but some of the newer stuff I just don't get how it goes together AB15s and MX6707s... Easy stuff. The older "main stream" stuff was very simple. The biggest thing is, I don't want to just buy some of these items when I really do not know if they go together for sure.

Murphy has a "power amp module mousing for the PRC-68 thru 136" I would assume this is the right amp but it does not look like the one in the picture on the PRC68 site. Then cables for interconnection...... HELP!!

no you dont need that, it is essentially what you have without the housing around it.. its just the power supply and Audio amplifier

Anyway..... In recap I assume I need an amp, the correct antenna/matching unit, speaker (since ls454 will not work), and power cables. Any help on part numbers or who has this stuff.

I really appreciate your help on this.

Antenna
You can make this work without the AMP and with a standard AS-1729/VRC antenna, your performance will vary a bit. This is because since you are running lower power output, then the efficiency of the antenna will be critical.. if you were running 100watts (as opposed to 2 watts) you could transmit into a proper, yet inefficient antenna and still do "ok". but with 2 watts, you go from poor to terrible with a inefficient antenna.

I would get it hooked up with the standard military antenna, then see how you do..

Speaker
You will want to rig up a speaker, the power supply and audio amplifier is designed to amplify the audio (not an RF amp) from the radio, but to get that you need to use the speaker output on the back. i havent tried the standard speaker, but it will work, although maybe not the best fidelity.. (but really in a mil vehicle is there any real need?). I have the pinout of the rear connectors, ill put a new page on my Wiki about this at http://www.radionerds.com

Summary
- you need a power plug
- you need a speaker / plug
- the antenna hooks to the antenna connector on the back


Questions
- What antennas (if any) do you have now?
- what kind of vehicle is this for?
- are you a HAM? if not what do you expect to do?
- got pictures of your OF-185?

- am i making sense at all... i been drinking since 9am.. JK...

Chris
K6RWJ

 

[Artillerydan]

Yes I have used the PRC68 site for years to figure out items I have come up with.

OK so would it be good to get the AM-7238B amp Murphy has to bost the output? Pricey but maybe something I should look for?

I have plenty of different antenna sets and bases and I do have the AS-1729

Not sure which vehicle I was going to put this in yet, but, the thought was the CUCV II Tahoe.

I am not a HAM, always been interested in the radio stuff but never pushed out any farther other than buying a PRC47 but never even used it other than playing with it for a few weeks. Still in the case (20 years ago) OMG time flies. My interest has always been working radios in my MVs. Years ago the club around here was very interested in communicating on trail rides but that has fallen away. Soooooo I have been trying to revive the (WORKING) radios in the MVs around here.

 

[ke6rwj]

Nice new unit! Jealous!!!

Ok so the antenna connector should be obvious.. Let's just shoot for something that works. If you use the mx-6707 (AS-1729 antenna base) you will need to manually change the band knob on it to match your radio freq, since it doesn't have a auto control.. ( I have a circuit to make a cool little box with a rotary switch to do that, but let's stay focused).
NOTE: I'm making the assumption you are using the VHF low band 30-75 MHz module on that radio, if it VHF hi band 136-174 then we need to rethink the antenna...which you got?

The power connector is a standard connector for nearly everything, I got mine from an old ac power chord from a mil spec ups. You might have to open it up and determine which pins are which. There are three pins, + - and chassis ground.

The speaker plug is also +- and chassis... Only three pins are used out of the 6.

The other big plug is for the amp if it were used, you don't need it.

The chrgr cable is if you have a rechargeable battery on the prc-128..

I think prc68.com might have the pin numbers for the plugs, if not I'll add them to my wiki tomorrow..

 

[ke6rwj]

Just saw you said you had the prc-68.. We good with the as-1729..

 

[hank2424]

i have a 175a/prc-9 can it be hooked up direct to vehicle or does it have to go through the specific amp..Please help needed parts , cables antenna , and mount for fender

 

[ke6rwj]

i have a 175a/prc-9 can it be hooked up direct to vehicle or does it have to go through the specific amp..Please help needed parts , cables antenna , and mount for fender

you pretty much need the mount to do it right http://www.radionerds.com/index.php?title=AM-589/U
the biggest issue are the power inputs they are very specific.