[Elecraft] [K3] K3 Audio Response - Version 3.33 Firmware

[Joe Subich, W4TV]

> Yes but unless the response remains that way when an 8 ohm 
> speaker is there its not a very useful measurement.

Since the speaker coupling capacitors are 470 uF, the roll off 
at 100 Hz with 8 Ohm speakers is 3 dB.  That's completely 
acceptable for a communications receiver ... and probably less 
LF roll off than you will observe due to the speaker enclosure. 

73, 

   ... Joe, W4TV 
 


> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net 
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Brett Howard
> Sent: Sunday, September 20, 2009 7:42 PM
> To: Ignacy
> Cc: elecraft at mailman.qth.net
> Subject: Re: [Elecraft] [K3] K3 Audio Response - Version 3.33 Firmware
> 
> 
> Yes but unless the response remains that way when an 8 ohm 
> speaker is there its not a very useful measurement.
> 
> ~BTH
> 
> On Sun, 2009-09-20 at 07:56 -0700, Ignacy wrote:
> > Is this measured with high impedance probes? If I remember 
> correctly, 
> > small caps limit low-frequency response of K3 especially with low 
> > impedance phones/speakers. Ignacy
> > 
> > 
> > As a further experiment, I just added 3 dB to Rx bands 1-3 and the 
> > response is now essentially +/- 0dB between 20Hz and 3.5 kHz in SSB 
> > through the 6K filter and Fc = 1.35.  You can lay the ruler flat on 
> > the response.
> > 
> > http://216.229.20.37/images/K3-V333-EQ.jpg
> > 
> > Paul, W9AC
> > 
> > ___
> 
> 
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
> 
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html