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Another M105 trailer modification- add Unimog Radio Box

oilcan

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Work, man... The Chief is out of the shop more often than not between OCT and JAN every year, and I need to stick around to keep the place running. Though we did talk about actually shutting down so I could take a vacation this year. (We TALKED about it...)
 

Another Ahab

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Though we did talk about actually shutting down so I could take a vacation this year. (We TALKED about it...)
KEEP talking about it.

Read Dr. Seuss and his "Green Eggs and Ham"; it's all there in the book.

You got nothing to lose.*

(* Full Disclosure: I used to be in Marketing and Sales)
 

oilcan

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Well, I do have another 10 months to put the screws to the boss. Maybe I'll have more reason to fight for it if we get some updates to this thread!

(See what I did there? ;-))​
 

Karl kostman

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Bob your imagination holds NO bounds and that is not even mentioning your level of execution it never less than beautiful Sir! What a truly great idea! And the 1300 is as awesome looking as ever Bob! Great job my friend!
Karl
 

tennmogger

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Adam pestered me enough to go out in the rain and take a few updated photos. :)

The radio table installation is complete but radios are still being added:

1) SEM-25, originally used in these comm boxes, 15 Watts or 1 Watt, with mounting plate/power supply and cabling, including AGAT (antenna matcher).
2) SEM-35 and grundplatte (mount) which interfaces the portable radio SEM-35 into the vehicle system, and allows control of the AGAT.
3) AGAT, the antenna matching box at the base of the antenna (antennenabstimmgerät).
4) modern Kenwood TM-821A, 2 meter transceiver, 65 Watt.
5) Israeli PRC-174 hf transceiver, 2 to 30 MHz, upper and lower SSB, AM, and CW. Includes an internal automatic antenna tuner.

The German radios operate from 26 MHz to 69.950 MHz, including the frequencies covered by the US tactical radios (typically for us, the older PRC-25, PRC-77, RT-524, RT 246) but adding the 26 to 30 MHz range. That range covers the 10 meter band which is quite active with FM signals when the band is open. I have made numerous distant contacts on 29.600 MHz, including Brazil.

By mounting the SEM-35 on the grundplatte, the '35 can now operate the AGAT to match the antenna, which it normally cannot do, and can run off the 24v system.

Not mounted yet is a PRC-77 with the U-383 power supply and desk mount.
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The box on the floor, above, is the SEM equivalent to the USA MX-7777 power distribution box and filter.

007.jpg

The blue battery is a NOS NiCad wetcell 24 volt aircraft battery to be used to power the radios. It will reside in the battery compartment of the radio box, along with another like it. That will provide about 30 AH of 24v power, not much, but the original radio generator will keep things charged (400W 2-cycle put-put generator/mosquito killer).

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The hanging bags were a lucky find from Washington State, thanks to a Unimog buddy. That is an original chair but I prefer one with wheels. However the original chairs clamp to the floor with provided hardware and are seat belt equipped. The box was permitted to hold 3 people during driving. Of course the loose stuff on the floor will be mounted on the radio table.

That's it for now.

Bob
WB4ETT
 
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tennmogger

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No clearance problem at all. The box has wheel wells built in. The axle was moved back to position the tires correctly.

Edit, I looked back at original pictures on this thread and I see why you saw clearance problem with the side of box. Sure looks like it! Actually it's a perspective problem. I found this picture showing the clearance, and measured a little over 3 inches before contact. The trailer will not gain much more weight, and 2 wheel trailer tires don't 'articulate' much so clearance is nearly constant.
 

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oilcan

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Quite nice, Bob. The pics and ideas are really getting the creative juices flowing in my head.
Side note... I have a PRC 320 set headed in my direction. Scheduled delivery date 12 JAN 16.
 

tennmogger

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You will like the PRC-320. It is one of the best thought out transceivers readily available on the market today. You know this (but for readers), the internal antenna tuner can be easily bypassed by removing the BNC jumper on the back and coming right out of the transmitter, and the internal reflected power indicator still works. An automatic antenna tuner (like LDG Z11-Pro) can be used and the results watched on the meter. The '320 provides an antenna tuning position with low output power, perfect for the external tuner. Of course the internal tuner will do most matching jobs if the antenna is chosen to agree with the chart on the radio. Cool radios, 2 to 30 MHz, but no LSB unless modified.


Bob
WB4ETT
 

11Echo

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tennmogger

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I was reading 'old' threads and notice I never responded. Mike Pop is a good friend and gave me the idea to put an Unimog 404 box on the M-105! One coincidence discovered when mating the box to the trailer was that the mounting centers of the German Radio box flex frames and the widths of the center-line of the M-105 trailer frame are the same! Convenient.
 

tennmogger

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Restoration/preservation is started on this box. The complete box has been media blasted and primed. Much more rusty metal to be cut out and replaced.
 
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