[Elecraft] KX3 Filter Blow-By

[M5FRA - Colin]

Jim, that prompted me to fire up the sig gen and have a look. On all HF 
bands I found that with an S9 +30 sig the opposite sideband is around 
55db down, i.e. around S3-4. With an S9 sig it is barley audible and it 
takes an S9+15 (approx) for the opposite sideband to register on the S 
meter. The settings were PRE (20db) = on, B/W 250Hz, XFIL=FL3. I did 
not get the the 50Hz sigs that you found. Could that have been front 
end overload? I use mostly CW and have not found any of this to be a 
problem. 
   
Colin - G8FRA/M5FRA 
   
m5fra.org.uk < http://www.m5fra.org.uk> 


------ Original Message ------ 
From: Jimk8mr at aol.com 
To: droese at necg.de;elecraft at mailman.qth.net;n6kr at elecraft.com 
Sent: 09/10/2012 13:48:23 
Subject: Re: [Elecraft] KX3 Filter Blow-By 
>I did some more careful checking this morning, transmitting a few 
>watts on 
>the FT-1000MP and using a couple of inches of wire as an antenna on 
>the 
>KX3, on a quiet 10 meter band. The S-meter on the KX3 was 9+ 
>
>There is noticeable opposite (lower frequency) side suppression 
>issues, 
>but this cuts off at about 900 Hz 
>
>On the higher side, I can hear signal to as far as my hearing and/or 
>the 
>audio chain permit. The most interesting note was that the undesired 
>signal 
>(high side only) takes a sharp dip or disappears every 50Hz, at .00 or 
>.05 
>on the frequency readout. 
>
>I'm not sure what to make of all this, but FWIW . . . 
>