[Boatanchors] URM-120 Wattmeter

[Bill Cromwell]

On Sun, 2012-09-02 at 14:12 -0700, Richard W. Solomon wrote:
> All the chatter about the URM-120 got my interest up.
> 
> I located one here in town and picked it up. It came 
> in the MIL Carrying Case and had a 1984 Contract Number.
> 
> The Meter and "Slugs" came fitted to a foam insert and 
> it looks like there was room for two more "Slugs" or 
> Coax Adapters or ?? The was also a slot for the manual, 
> which was missing, but had a copy in its place.
> 
> Next step is to check it against my Bird 43. Not sure 
> what to make of that since absolute RF Power Measurement 
> is quite difficult, but at least I can see how close they 
> are to each other.
> 
> 73, Dick, W1KSZ


Hi Richard,

I've had mine for quite a while. I don't know how to find the contract
date but my best guess looking at the tags is 1974. That 74 might mean
"inspected by #74" for all I know. Mine is in a steel box with
compartments for each of the three "slugs" with plastic caps for each
slug when stored. There is no foam. There is no separate compartment for
a manual but one would probably fit. I have the 8 1/2 X 11 reproduction
manual from Fair Radio in the file drawer. The "slugs" can be adjusted.
There is an adjustment for each power range on each slug. If we keep in
mind that watt meters have tolerances in terms of the full scale reading
it won't work to calibrate against your Bird unless you have four
appropriate slugs each for the three in your 120. I just set mine with a
scope and a 50 ohm load. Somebody had already been in there trying
apparently to set all the ranges with a Bird and one, high power slug.

I think it's pretty useful to have all those frequency ranges AND power
levels with one set that doesn't require a second mortgage on the house
and a lien on the dog.

73,

Bill  KU8H