[Elecraft] K3 AM operation with "FM" roofing filter?

[Joe Subich, W4TV]

Knut,

> I am still confused as to whether I can *receive* AM with the 
> FM roofing filter with the *current* firmware. Can someone 
> please give me an authoritative answer on this? I have just 
> received the FM filter and the included note seems to imply 
> that I have to wait for an firmware update. I am not asking 
> whether I can get more than 3kHz audio BW on AM with but just 
> simply if it will work?

The unequivocal answer is - it will work but with only 3KHz 
audio under the current firmware (DSP ver 1.58).  My factory 
built K3 was delivered with MCU 1.78/DSP 1.58 and the FM 
filter).  With the current public firmware, FM is not functional
and AM audio is limited to 3 KHz (even with the FM filter). 

Wayne has said publicly that both FM and wider AM (to 5 or 6 KHz 
audio response - 10 to 12 KHz IF bandwidth ) is coming in the next 
version.  

73, 

   ... Joe, W4TV