[Elecraft] Filter Selection Approach

[James Sarte]

I agree with Joe,

Save your money where you can.

Here's what I have configured:

Main: 13 - 6 - 2.7 - 400
Sub:  13 - 2.7 - 400

The 6k in the main is used for AM or ESSB.  The 13K on the main is for FM
transmissions, while the 13k in the sub is used for AM receive.  I use the
400 for all other modes like CW or data, and if needed will use the DSP to
taper down.

73,
James K3JPS

-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Joe Subich, W4TV
Sent: Tuesday, April 14, 2009 9:41 AM
To: 'Ed G'; elecraft at mailman.qth.net
Subject: Re: [Elecraft] Filter Selection Approach


That is a lot of filters ... 

1) The DSP is quite effective and there is not much difference 
   (if any) in the performance of the 2.8 KHz 8-pole filter vs. 
   the 2.7 KHz 5-pole filters.  Even if one pays the extra $30 
   for a matched pair of 2.7 KHz filters, the added cost of the 
   2.8 KHz pair is $180.00 

2) Unless you are in very heavy QRM/pile-up situations the 
   roofing filter does not provide a lot of "value added" 
   since the final bandwidth is determined by the DSP.  The 
   1 KHz filters add little benefit vs. the 1.8 KHz or 1.5 
   KHz filters.  

3) The 13 KHz filter can be used for AM receive - there is 
   no benefit in having both the 13 and 6 KHz filters in the 
   sub RX.  It is a shame that Elecraft still do not permit 
   use of the 13 KHz for AM and ESSB transmit (even if it 
   were offset 3 KHz in transmit for additional image rejection). 

A less expensive line-up that seems to provide maximum 
(IMO) flexibility/performance is:  
  Main:  13 - 2.7 - 1.8 (1.5) - 400 - 200 
  Sub:   13 - 2.7 - 400 

73, 

   ... Joe, W4TV