[Elecraft] Swapping Standard 2.7 kHz 5-pole Filter

[Eric Swartz - WA6HHQ, Elecraft]

Hi Bill,

This is incorrect. The 2.7 kHz 5-pole can only be swapped for a 2.8 kHz 
or possibly the 2.1 kHz 8 pole filters. We require at least one SSB b/w 
filter in each K3 as it ships since we must also transmit through the 
filter for SSB and data modes. Transmitting through the 2.1 kHz filter 
will limit your tx bandwidth to that value. ( I'm not aware of many 
choosing the 2.1 as their only SSB filter - I may drop that as a swap 
option to make sure no overly narrow TX K3s get out there and confuse 
the market.)

I'll post some more detailed DR numbers on the 5 pole vs 8 pole filters 
in the next couple of days. The short answer is that the 5 pole filters 
have slightly less IMD3 dynamic range and a wider shape factor than the 
8 pole filters, but both are very good. The 250 Hz 8-pole and the 200 Hz 
5 pole are both at least 95+ dB DR3 at 5 kHz, with the 8 pole beating 
out the 5 pole by several dB. We've been testing a number of each filter 
on a range of K3s to make sure we can conservatively spec them across 
filter variations and rig variations. :-)

One other note - The sales person you talked to is Annika. There is no 
Monica at Elecraft, unless they are hiding her somewhere! ;-) She was 
clear on  which filters could be swapped for the 2.7, but I'll check 
with her for sure tomorrow.

73, Eric WA6HHQ
(Now back to work!)


Bill Tippett wrote:
>
>
>         According to Monica at Elecraft, it's possible to swap
> the standard 2.7 kHz 5-pole filter for either the 2.8 kHz 8-pole or
> the 400 Hz 8-pole for an incremental $90 ($30 credit plus the
> standard $120 charge for 8-pole filters), but only the 2.8 kHz
> and 400 Hz may be substituted for the standard filter.
>
>         Now if we only knew if there were any difference in
> IMD/BDR performance we could make a rational decision...
>
>                                 73,  Bill  W4ZV
> _