[Elecraft] Filters

[Jim Brown]

On Mon,1/30/2017 5:21 PM, mtruss wrote:
> I have purchased a used  K3, serial number 3000 or so, it has been sent back
> to Elecraft for updates etc  and returned to me working great so far. I
> would like to update some things especially the roofing filters first so the
> question I would like to ask is  Has anybody upgraded from the 2.7 five pole
> filter to the 2.8 eight pole filter?

I have 2.8 kHz filters in the main receiver in both of my K3s. I like 
them because they're a bit flatter in the passband, which reduces the 
incidental AM when I'm transmitting RTTY. The steeper skirts also do a 
bit better in the presence of strong signals.
> I understand the 8 pole is a wider
> filter with 3 more filtering  crystals , does it make any difference in
> received audio?

Not that you would notice.

> also could I use the fm filter for use in the am position.

I'll let Don or Wayne answer that with respect to TX.  I don't TX AM, 
but I sometimes tune down to the AM BC band to verify the directivity of 
my RX antennas.

73, Jim K9YC