[Elecraft] K3s with sub receiver - filter mix and match question

[Joe Subich, W4TV]

> Groping into my blurred memory, I think the benefit of having similar
> bandwidth filters (e.g 400hz, 2.7Khz or 2.1 KHz) in the main and sub
> receiver is diversity reception but I’m not sure.
"Matched" filters were required for optimal diversity operation
with the *original* synthesizer.  With the new synthesizer in
the K3S, that requirement has been relaxed.

> Does it matter if I installed either of these single filters on the 
 > main or sub rx?

No.  For example, I have 13 KHz (FM), 2.8, 1.8, 500 (8 pole) and 200 Hz
in my main with 2.8 and 500 (8 pole) in my sub rx.  Since I have the
new synthesizer, I can use matched filters for Diversity or select a
tighter filter in the main RX and continue to use a wider view in the
right ear (sub rx).  From a DX (split) perspective, I can use a narrow
filter in the main (for the DX) and the wider filter in the Sub RX for
"listening in the pile-up".

If you are one that likes to park the Sub RX on the DX station and
"lock" VFO B, then transmit on VFO A ("split off") and tune around
the pile-up, you may want to put the narrow filters in the Sub RX.

73,

    ... Joe, W4TV


On 2021-07-05 3:30 PM, PAUL GACEK via Elecraft wrote:
> Simple question: Can I mix and match different filters between the main and sub receiver. If yes, what am I giving up?
> 
> Groping into my blurred memory, I think the benefit of having similar bandwidth filters (e.g 400hz, 2.7Khz or 2.1 KHz) in the main and sub receiver is diversity reception but I’m not sure.
> 
> In my project to install a KRX3/KSYN3A into a K3s, I have a pair of 2.7Khz filters and a pair of 400Hz filters. Separately, I have a variety of single filters such as a 250 Hz and 1.8Khz.
> 
> Does it matter if I installed either of these single filters on the main or sub rx?
> 
> Paul Gacek
> W6PNG/M0SNA
> www.nomadic.blog
>