[Milsurplus] URM-25D...

[aGEnuine Ham]

Ken:

How are you connecting the counter?  If you are trying to measure
ultimate sensitivity with the counter connected, forget it.

On the other hand, if the URM-25 case hasn't been boogered, you are using
RG-223, 142 or other equivalent double shielded coax, with the connectors
properly installed, and the receiver is fully buttoned up in its case,
then you should get accurate measurements.  A good test is to simply move
things around in relation to each other, and see if the output indicator
on the receiver changes.  That will tell you if there is a direct path
other than the coax which is confusing the readings.

73,
George
W5VPQ

On Fri, 13 Jun 2003 21:56:34 -0700 "Kenneth G. Gordon" <keng@moscow.com>
writes:
> I have a really nice URM-25D here which I am using to aid in 
> the alignment of the SRR/FRR receivers I am overhauling.
> 
> I use it with a nice little frequency counter I got from surplus 
> here at the U.of I.
> 
> My unit didn't come with all the accessories, so I plan to build 
> those which are missing.
> 
> I am curious if anyone else here has had to do this and what 
> were your results?
> 
> Also, is the attenuator in the URM-25D fairly accurate? Is the 
> unit really RF tight, or only somewhat?
> 
> The reason I ask is that when I get down in the sub-microvolt 
> region, the signal strength doesn't appear to get weaker 
> linearly. I still hear signal at what the URM-25D says is less 
> than 0.1 microvolt and that seems truly amazing to me.
> 
> Ken Gordon W7EKB
> _______________________________________________
> Milsurplus mailing list
> Milsurplus@mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/milsurplus
> 


________________________________________________________________
The best thing to hit the internet in years - Juno SpeedBand!
Surf the web up to FIVE TIMES FASTER!
Only $14.95/ month - visit www.juno.com to sign up today!