[Elecraft] Filter questions

[Dick Dievendorff]

Is it possible that your narrow filter has cut off the desired signal?

Make sure your CW pitch is reasonable and you've tuned a little bit for the
signal with the narrow filter.  

If your CW pitch is different from where you're listening at a wider
bandwidth, the signal can disappear when you tighten the bandwidth.  I'd
recommend tuning in a steady carrier with the CWT and/or spot buttons, and
then narrow the bandwidth. 

If the CWT doesn't center at a comfortable pitch (this is a personal
preference), adjust it by entering CW mode, HOLD the Pitch button (it's
labeled "Spot" for its tap function) and rotate VFO A until you get a pitch
you like.  I prefer about 400 Hz, your preference may be different than
this.

Also make sure that the Filter Configuration has the filters enabled by
mode. The K3 Utility's Crystal Configuration Dialog can be used to quickly
view the filter configuration, it's available by clicking the "Edit Crystal
Filters" button on the K3 Utility's Config menu.

I understand that you may have tried all this...

Dick, K6KR


-----Original Message-----
From: elecraft-bounces at mailman.qth.net
[mailto:elecraft-bounces at mailman.qth.net] On Behalf Of W5UN
Sent: Monday, November 17, 2008 9:23 AM
To: elecraft at mailman.qth.net
Subject: [Elecraft] Filter questions

I will ask here before calling Elecraft.

First, I have the following filters installed on the main rcvr, all 8 
pole: 6 Khz, 2.8kHz, 1.8 kHz, 400 Hz, 250 Hz.

There are two issues:

1. When I turn my 250 Hz filter on in config, and then select that 
filter (which is FL5 here)I can hear noise coming through but no cw 
signals come through. I can see the signals on my PowerSDR/LP-PAN 
setup and CW Skimmer. Signal comes through all the rest of the 
filters O.K. Yes, I opened the radio, and all the filters are installed.

2. I run CW Skimmer with my K3. When I change filters, the CW offset 
signal shown on CW Skimmer changes. I thought the 8 pole filters had 
no offset. Is anyone else experiencing this? Any comment appreciated.

Dave, W5UN

_______________________________________________
Elecraft mailing list
Post to: Elecraft at mailman.qth.net
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft    

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com