installing MT-298/gr in M38 - TM

Lyle · Post by **Lyle** » Sun Jul 28, 2024 3:39 pm

I'm searching for the TM or Installation manual for the MT-298/gr.

I believe the MT-297/gr will show the cable connection to the distribution unit. that both setups utilize.

As always any help will be much appreciated.

RonD2 · Post by **RonD2** » Sun Jul 28, 2024 4:18 pm

Hi Lyle,
Not sure I understand the question.

Did you get the copy of the Installation Instructions (link) sent in answer to your previous thread here?
http://willysmjeeps.com/v2/modules.php? ... stallation

Lyle · Post by **Lyle** » Sun Jul 28, 2024 7:12 pm

Ron, yes I received the Lin and have downloaded and printed it.

It does not have the details of the M-298. It has the details for terminating the VRC/375.

I need to add and wire in Another “Int-cont” (W-7) and “Rec-control” (W-2).

The TM you shared does not have the termination detail for those cables.

RonD2 · Post by **RonD2** » Sun Jul 28, 2024 7:29 pm

Which Radio Set are you installing?

Will it be a "stock" or standard installation, or something customized?

Lyle · Post by **Lyle** » Sun Jul 28, 2024 8:22 pm

RT-70 with amp, RT-68, 112 power supply, R-109. With 435

Post by **wesk** » Sun Jul 28, 2024 9:36 pm

Those radios can be installed in several different installations both left side or rear of jeep. Which master Signal Corp drawing are you using for the entire set and what are the set item numbers?

I'll send you a copy of the Sig Corp Radio Set Index so you can tell us which set you have and which drawings you are looking for. You can also view it's 10 pages in my Military Radio Album: http://www.willysmjeeps.com/v2/modules. ... _album.php

I may also have the TM's for your sets as well.

RonD2 · Post by **RonD2** » Sun Jul 28, 2024 9:45 pm

RonD2 wrote:Which Radio Set are you installing?

Will it be a "stock" or standard installation, or something customized?

Hi Lyle,
The "RT" (Receiver-Transmitter) is a component part of a Radio Set.

According to the manual, what you have is either the AN/GRC-7 or AN/GRC-8 Radio Set --- except for your R-109 Receiver.

AN/GRC-7 is equipped with RT-68 and RT-70 with R-110 Receiver.
AN/GRC-8 is equipped with RT-68 and RT-70 with R-108 Receiver.

The R-109 Receiver is supplied with the AN/GRC-5 Radio Set (RT-67 and RT-70).

If it helps, here's a link to TM 11-284 for Radio Sets AN/GRC-3, 4, 5, 6, 7, and 8.
It might have the interconnect information you seek (175 pages plus schematics).

https://www.radionerds.com/images/4/4f/TM_11-248.pdf

Note the file name is wrong (says -248, should be -284).

Good luck!

Lyle · Post by **Lyle** » Fri Aug 02, 2024 11:12 am

I've found a drawing with the best info on how to terminate cables: W-2, W-5 and W-7 to Mounts: MT-297 & 298.

TM 291-11, Figure 74.

I'm brain-dead from over 30 hours of researching and reading, including 400 pages printed out.

RonD2 · Post by **RonD2** » Fri Aug 02, 2024 11:46 am

Glad you found what you needed Lyle.
Thanks for letting us know.

That would be TM 11-291 for the Radio Set AN/VRC-13, 14, and 15.
Link here: https://radionerds.com/images/3/3b/TM_11-291_1951.pdf

The AN/VRC-13, 14, and 15 don't use the RT-70 --- so everybody is still guessing which Radio Set you have.

Maybe you can you give us a hint?

By the way, the same schematic diagram is Figure 91 on page 163 of TM 11-284 that I posted earlier:

RonD2 wrote:If it helps, here's a link to TM 11-284 for Radio Sets AN/GRC-3, 4, 5, 6, 7, and 8.
It might have the interconnect information you seek (175 pages plus schematics).

https://www.radionerds.com/images/4/4f/TM_11-248.pdf

Note the file name is wrong (says -248, should be -284).

Lyle · Post by **Lyle** » Fri Aug 09, 2024 1:10 pm

Need help with identifying circular connector for W-5, W-7 on the mounts MT-297, MT-298, MT-299.

They are the 9-connectors (Pin) with the draw screws.

I have been unable to find any TM that lasts the parts for these mounts. I did find how to wire them but no part numbers for the connectors.

RonD2 · Post by **RonD2** » Fri Aug 09, 2024 1:21 pm

The connector on the end of the cable or the connector on the mount?

I guess I can do a search for you.

How about this.......did you see the descriptions of W-5 and W-7 on pages 137 and 138 of this TM that I provided earlier?
Here: https://www.radionerds.com/images/4/4f/TM_11-248.pdf

Are you looking to buy replacements or repair parts for them?

Still wondering which Radio Set you have or are building.........

Lyle · Post by **Lyle** » Fri Aug 09, 2024 4:59 pm

Ron, yes I have the TM printed out. After reading those sections last week they referenced a drawing that I can’t find.

I need two of these connectors to add two New cables to the MT-298.

As for radio setup the odd man out is the R-109. So I’m looking for a R-110 to complete the setup.

RonD2 · Post by **RonD2** » Fri Aug 09, 2024 5:53 pm

Lyle wrote:As for radio setup the odd man out is the R-109. So I’m looking for a R-110 to complete the setup.

What "set up"?
You still haven't told us.
I'm guessing --- AN/GRC-7 ?

Probably easier to find complete cables instead of the piece parts to build them.

Lyle · Post by **Lyle** » Sat Aug 10, 2024 9:35 am

Ron:

Radio Set: AN/GRC-7

Type of vehicle: Truck 1/4Ton 4 x 4 Utility M38 (24-volt)

Stock numbers:

Complete equipment: 2812-7-V76

Basic unit: 2812-7/24

Installation Unit: 2512-3-V76/50

Although the AN/GRC-7 includes a R-110 I’m using a R-109 which all TM’s regarding this substitution seems to allow it. And I have all the proper antenna bases and antenna elements.

Lyle · Post by **Lyle** » Sun Aug 11, 2024 11:39 am

I need help in finding any TMs on the following:

MT-298/GR - Mounting Base, Electrical Equipment (NSN 5975-00-665-1292)

MT-299/GR - Mounting Base, Electrical Equipment (NSN 5975-00-224-6960)

I specifically need the part numbers for the amphenol/bendix connectors for the W-2, W-5 & W-7 cables.

The actual cable used I’ve sourced.