[ARC5] URM-25 mods

[Ian Wilson]

Here is some useful information that I gleaned:

http://www.wb6nvh.com/DATA/Lankfrd.pdf

For leakage make sure that all internal shields are making complete
contact as well as the panel to case and rear to case are RF tight.
This incluses the attenuator assembly.

Add ferrite beads to the line cord inside the case.

For the output use double shield coax wrapped around a FT240-43 toroid
(Mouser has best price) and into a mil spec step attenuator. Don't
rely on the low output positions of the 25D for accuracy and come out
at a higher level into the external attenuator. You can then see
reliable accurate attenuation right into the noise for MDS tests.


73, ian K3IMW

On Sun, Oct 6, 2013 at 7:57 PM, Ian Wilson <ianmwilson73 at gmail.com> wrote:
> Geoff,
>
> In a post (which I can't find right now), you mention mods to
> reduce leakage, etc, from the URM/25-x. I use my URM-25/D as
> my main signal generator, and would be interested in any mods that
> improve the accuracy at low output settings, etc.
>
> 73, ian K3IMW
>
>