On Sun, 28 May 2017 21:22:33 -0700, Jeff Liebermann
wrote:

On Mon, 29 May 2017 08:45:50 +1000, Clifford Heath
wrote:

I downloaded, see he
https://www.dropbox.com/sh/z91pqvcpg470tuy/AAAIRnVfRDqrbrJwA3yBVQVPa?dl=0

I missed the translated user manual (in English). It shows a
sensitivity graph for the high frequency range with the following
comment from Pg 12:
It is noted that the UHF channel allows measurements up to about
450 MHz. This path comprises a divide by 64 stage claimed to be
able to operate to 2.4GHz according to the published specifications.
It is therefore surprising that the sensitivity fell as quickly
as it did.
Looking at the schematic and layout, my never humble opinion is that
the designer didn't know anything about RF design and layout.

The schematic shown on Pg 13 is quite different from either the old or
new versions of the design that I previously mentioned. Instead of
the extra divide by 4 packages, it has a 2nd DG MOSFET in front of the
PIC counter. It also lists the prescaler as an MB506 which is divide
by 128/256, not 64. It also shows that the gates of the DG MOSFET are
NOT tied together.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558