[Amps] Dummy Load DA-174/GRM-10

[jeremy-ca]

It sounds as if it may be a reactive dummy load for performance testing the 
specs of a TX or small amp. But is there any switching of jumper options? 
The resistors should be non inductive, maybe Dale or similar brand.

The ones Im familiar with use a big rotary inductor and a vacuum variable 
with calibration charts to set a wide range of possibilities. However they 
were used for 1 to 5KW units. I have one here that was in use for many years 
at National Radio military division. It still comes in handy.

Carl
KM1H


----- Original Message ----- 
From: "Keith Schreiber" <schreiber at alltel.net>
To: <amps at contesting.com>
Sent: Wednesday, July 18, 2007 6:21 PM
Subject: [Amps] Dummy Load DA-174/GRM-10


> Greetings to the group!
>
> I'm trying to trace down a schematic or any info on the following item :
>
> Dummy Load, Electrical  DA-174/GRM-10
>
> I've not been able to find anything about it on the net.  This gizmo has a 
> Simpson 0-10 RF Ammeter on the front, a squirrel cage blower (with switch 
> & pilot light) that cools many 20 watt, wire-wound resistors.  These 
> resistors are all mounted in a phenolic box, which the blower forces air 
> through, and then out the back.  The cabinet is filled with all kinds of 
> fixed inductors and 850 series doorknob caps.  The dimensions are roughly 
> 9" wide  X  10" high  X  15" deep.  The input is a female N connector. 
> The input connector and the 0-10A RF ammeter are mounted on a 1/4" thick 
> phenolic plate (on the front panel.)  The cabinet itself is all aluminum, 
> with screened vents on the left side and the rear.  It's gray in color. 
> The front panel also has a fuse for the blower and a black, 5-way binding 
> post for a ground connection, in the lower left corner.
>
> This is the first time the web has let me down in finding info on 
> something.  The only info I was able to find on this item, was it's NSN 
> (National Stock Number) :
>
> 5985-01-261-4595
>
>>From that number, I've seen references that it was made by 
>>Rockwell-Collins at some division in Richardson, TX.  I've got a number 
>>called a "CAGE" number too.... if that means anything to anybody. (80058)
>
> I'd appreciate any info, that anyone could provide.  Perhaps you used one 
> of these in your military days.  I don't even know the frequency range. 
> It will not accept power (SWR=19) and an ohmmeter applied to the center 
> pin of the N connector, shows "open" to ground.  No doubt one of the many 
> 20W wire-wound resistors that actually make up the load is open.  But the 
> way this thing is put together, it's going to be a real chore finding out 
> which one.  Especially without a schematic.
>
> Any info on this?  I guess it would be best to reply to my regular e-mail 
> schreiber at alltel.net
>
> Thanks & 73 from W8KTH
> Keith
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