Fwd: Re: [Elecraft] SV: Getting Ready For The 2nd RX

[Bill Tippett]

Hi Orin,

        Copying this to the list since others may have a similar situation.

On Wed, May 28, 2008 at 9:08 AM, ORIN G. HELVEY,JR. <orin7 at juno.com> wrote:

>        On the filters, I had planned to only install a 0.500 in the second
> receiver as I thought I would probably only be using it on 160 cw. I
> already have these two filters.  One is -.85 and one is -.84. Would you
> advise sending one back for an exact match, or is this close enough?

        In my opinion that's close enough (i.e. 10 Hz offset
difference or <2% which you'll never notice out of 560 Hz total
bandwidth) but you must set both to the same number when you set up
your KRX3 if you plan to use diversity (i.e. both either -0.85 or
-0.84).  If you didn't do this, you would hear a "warble" or frequency
difference when attempting to SYNC both RXs to the same VFO.  Elecraft
will eventually publish some instructions regarding 5-pole filters for
diversity, but my understanding is that the peak variation between 500
Hz filters is a maximum of 50 Hz.  My guess is that they'll simply
tell us to split the difference on the 500s and not worry about it.
If the 200 Hz has total variation of  50 Hz, then it might require
more careful matching (since 50/210 is a significant percentage of
total BW), but I've not seen any variation numbers on the 200 yet.

                                              73,  Bill  W4ZV