[Elecraft] [K3] LPF DSP modification

[Joe Subich, W4TV]

> ???  Are you saying that Elecraft makes additional changes on 
> the "C" board that are not part of the LPF addition?

Yes, you can find them by comparing the January 2010 schematics 
to previous schematics.  The changes are similar to the W9AC mods 
but they involve scaling resistors instead of capacitors. 

The changes are not necessary if: 1) you use high impedance 
headpones and 2) you don't care to create multiple "false 
carriers" in ESSB operation (extended low frequency transmit). 

The "low frequency response" modifications are strictly for 
extended response below 100 Hz. 

73, 

   ... Joe, W4TV 
   


> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Grant Youngman
> Sent: Monday, March 08, 2010 12:05 PM
> To: Elecraft Reflector
> Subject: Re: [Elecraft] [K3] LPF DSP modification
> 
> 
> 
> On Mar 8, 2010, at 10:05 AM, Joe Planisky wrote:
> 
> > 
> > Do note that the LPF mod does NOT give you the extended low 
> frequency
> > response on TX and RX that you would get with the board 
> exchange.  If  
> > that's not important to you, then the DIY option is a good 
> way to go.
> > 
> 
> ???  Are you saying that Elecraft makes additional changes on 
> the "C" board that are not part of the LPF addition?
> 
> Grant/NQ5T 
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