[Elecraft] K3 Roofing filters

[Edward R Cole]

Excellent answer from Don, W3FPR.

I fit the mostly SSB type with sub-Rx, so I use diversity 
reception.  I chose for the main Rx:
13-KHz (for AM and FM)
2.8-KHz
400-Hz

The sub-Rx has just the 2.8-KHz filter

I chose the 8-pole for ease in set up for diversity Rx and for the 
steeper skirts (which I may not really needed up here in AK, but I 
figured made the resale value better).

The DSP bw control works fine and I often narrow the high split on 
weak or noisy SSB to improve reception.  I keep the low split at 
200-Hz.  The 400-Hz filter makes CW reception of a single station 
possible.  400-Hz filter is really amazing.

I have not used it on CW eme but expect it will provide some 
advantages in narrowing the noise bw.  Typically, I run 100-Hz for 
eme CW once I have the signal tuned.  Scanning for eme signals I use 
the wider SSB bw and waterfall displays to detect the signal.

Most of my eme on 2m is using digital mode so no filter is used as I 
export the IF of the K3 to LP-Pan and therefore to a 
soundcard.  Digital eme is watched not heard.  I actually have the K3 
select an empty filter slot when running DATA-A which eliminates a 
center frequency gain "suck out" (black zone on zero freq display).

73, Ed - KL7UW
http://www.kl7uw.com
dubususa at gmail.com
"Kits made by KL7UW"