K3 roofing filter IMD

classic Classic list List threaded Threaded
1 message Options
Reply | Threaded
Open this post in threaded view
|

K3 roofing filter IMD

Dave Hachadorian
I was perusing the Sherwood Engineering receiver evaluation
data, http://www.sherweng.com/table.html , and I noticed
that the K3 2 KHz dynamic range is reported to be
significantly better with the 200 Hz 5-pole roofing filter
than with the 400 or 500 Hz filter.

Then I came across some IMD data on the K3 Wiki,
http://www.zerobeat.net/mediawiki/index.php/K3_Roofing_Filters ,
which does not show much difference between those filters,
but has an interesting footnote:
"It should be mentioned that in a published review of the
K3, G4AON observed degradation of close-spaced IMD
measurements with the 400 Hz, 8 pole filter: "These figures
are for a 400 Hz bandwidth with the 8 pole 400 Hz roofing
filter, the rather surprising discovery was the dynamic
range improved by almost 10 dB when the 2.8 KHz 8 pole
filter was selected." G4AON's findings haven't yet been
independently
confirmed however."

Any thoughts on resolving these apparent inconsistencies?

Dave Hachadorian, K6LL
Yuma, AZ






















.


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com