[R-390] URM-25 RF output measurement

[Bob Camp]

Hi

Well if you wanted to set up specifically for R-390's there is a magic 
table in the manual that spells out the frequencies to use for 
alignment. Roughly it works out to three frequencies per octave. It's 
not quite every MHz but it's close to that on the low end.

It's probably more reasonable to do the top bottom and middle of each 
range of the URM-25. Maybe use something like 10% in from the ends and 
the middle.

The levels you care about are generally the ones down around a 
microvolt.  If you know you are on say at  0.1,  1 , and 10 uv then you 
have a pretty good idea of what your generator is feeding the radio. If 
the generator has to crank more than 10 uv in a sensitivity test then 
your R-390 is pretty sick ....

If there's any interest I can probably make up some of the CMOS level 
standards. Somehow I seem to have most of the parts lying around here 
..... they should be pretty cheap. Depends a lot on how nice a box we 
want to put them in.

	Enjoy!

		Bob Camp
		KB8TQ


On Jul 7, 2004, at 7:36 AM, Veenstra, Lester wrote:

> Assuming the response is modest, I offer my service to measure 
> URM-25(x)
> at a number of significant freqs and levels (but please do not ask for
> every MHz at every 5 dB).
>
> So, since my days of actually working on 25's is lost in memory: what
> would be an appropriate set of frequencies and levels that should be
> verified, according to the real experts here on the "net"?
>
> The selective level meter in its relative mode should make checking out
> the attenuator for discontinuities a simple process.
>
> I use a pair of HP-436 power meters with standard and high sensitivity
> heads and an HP-3586 selective level meters.
>
> Les Veenstra  (K1YCM/3) (CTM1)
> Frederick MD
> 301-571-1212
>