allison,
i tried two different tracking generators based on the hetrodyne principle.
they both leaked into the IF badly, raising the noise floor by 15 db.
Now, instead, I am going to try an Si5351 directly at the signal frequency.
I did try the CMOS version of Si570. but i noticed more spurs than with the
LVDS version. I am not sure if I must attribute it to the LVDS version
alone. I had substantially increased the shielding between changing the
Si570 type.
- f
On Sat, Aug 29, 2015 at 11:59 PM, allison <ajp166@xxxxxxxxxxx> wrote:
Farhan,
One suggestion:
Add tracking generator (difference of first osc and second, filter and
pump up with amp)
as then it adds sweeperino capability another useful function in one
instrument. It adds
little to the complexity but adds huge functionality.
One comment. Shielded modules, dead bug or PC are a must to get the
best result.
Allison
On 08/28/2015 01:01 AM, Ashhar Farhan wrote:
While working on the Minima project, I needed a spectrum analyzer to
measure the performance. The new specan is as complicated as a simple
SSB rig, probably even simpler.
This is an Si570/Arduino controlled spectrum analyzer that can be
built for less than hundred dollars. It is simple to build and it can
be used to measure IMDR, spurs, harmonics, etc. It doesn't need an
oscilloscope.
I like you all to read about
it http://hfsignals.blogspot.in/p/specan-reboot-of-w7zoi.html
- f
