[Elecraft] Filter width and cutting off CW

[David Ferrington, M0XDF]

Thanks for all the responses - to answer the questions:

Yes I'm in CW mode
yes I've used Spot and shift shows an * to indicate its centred over  
the frequency
I've checked the filters and offsets, receive Filter Enables etc in  
Configuration etc.

the loss of signal occurs at 500Hz, that’s before the filter switch  
point at 400HZ
I have checked against RWM on 9.996 band it cuts of in the same way at  
500Hz

It appears that once I go down to 500HZ, the signal is greatly  
attenuated and I loose the side tone, regardless of mode, the  
frequency is attenuated at that point - I can just hear the  
transmission, but everything is very attenuated. I'm wondering if they  
made be a bad connection of a part of the board that only comes in  
below 550Hz.

When RWM is transmitting just a carrier, it gets cut off at 500Hz
-- 
Always remember, half the people in the world are above average  
intelligence!

On 20 May 2008, at 21:46, Dave G4AON wrote:

> Hello David
>
> I don't know what you are doing wrong, my K3 works just fine right  
> down to "50 Hz". I am using the latest firmware, 6 KHz, 2.8 KHz and  
> 400 Hz filters. You could check on a plain carrier too.
>
> Your choice of a 500 Hz pitch works, but I don't know of anyone who  
> normally uses such a low pitch. I mostly use 700 Hz but have checked  
> at 500 and it worked just as well.
>
> Have you somehow got a filter incorrectly set with an offset instead  
> of 0 Hz (only the cheaper 5 pole filters have an offset, 8 poles are  
> zero Hz)? Also, did the loss of signal occur when the XFIL display  
> showed a change of roofing filter, as the filter should only change  
> when you go down to 400 Hz? Another thing, is your centre frequency  
> the same as your chosen pitch (indicated by a  * against the shift),  
> if your filter isn't centred you would lose the audio.
>
> 73 Dave, G4AON
> ================
>
> I'm just finally getting into hunting for CW on the bands to listen
> to, to help improve my on-air listening - I can read about 7WPM (20
> char speed) and trying to find signals with my K3.
> I can hear a few around on 40m with the filter set to 1.8KHz, but when
> I start to reduce the filter width down, I loose it at 500Hz - I can
> hear very well at 550Hz, but drop the 50Hz and it disappears - this is
> after doing an auto spot.
>
> Tuning around the frequency, I still can't find it.
> Is this a combination of filter width and my sidetone pitch, which is
> set to 500Hz?
>
> I have latest beta f/w, a 400Hz, 1.8KHz, 2.8KHz and 6kHz filters
> 73 de M0XDF, K3 #174