[Elecraft] K3 Future Factory Hardware Updates; + New beta f/w release 3.27

[Alan Bloom]

The resistor change increases the IF output signal by a little over 10
dB.

It's interesting to note that changing the FET source resistor does not
result in a 50-ohm output impedance because the resistor is in parallel
with the FET source resistance.  A 50-ohm match is not required in any
case.

Al N1AL


On Tue, 2009-08-25 at 16:11 -0400, Joe Subich, W4TV wrote:
> Eric, 
> 
> > Please note that the last item, the IF Output Buffer Gain mMod, 
> > is slightly different than the similar N8LP mod some have been 
> > performing on their K3s independently. We determined that only 
> > one value needs to change to implement the gain increase for 
> > the IF output. We are changing R8 from 1K ohms to 13K ohms.  
> 
> Are you saying it is not necessary to increase the current in 
> J309 to handle the higher signal levels?  
> 
> With this change, what is the transfer gain/loss from the antenna 
> input to the IF output with the IF output terminated in 50 Ohms? 
> 
> 73, 
> 
>    ... Joe, W4TV 
>  
> 
> 
> > -----Original Message-----
> > From: elecraft-bounces at mailman.qth.net 
> > [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Eric 
> > Swartz - WA6HHQ, Elecraft
> > Sent: Tuesday, August 25, 2009 1:53 PM
> > To: elecraft at mailman.qth.net
> > Subject: Re: [Elecraft] K3 Future Factory Hardware Updates; + 
> > New beta f/w release 3.27
> > 
> > 
> > Hi Roy,
> > 
> > As of today, we have made the following enhancements to all 
> > K3s leaving 
> > the factory:
> > 
> > K3 VFO TUNING NOISE REDUCTION  (requires f/w 3.25 or later)
> > K3 AUTOMATIC FRONT END PROTECTION  (1 wire mod)
> > K3 IF OUTPUT BUFFER GAIN MOD (For the P3, LP-PAN etc) (1 
> > resistor value 
> > change)
> > 
> > Based on feedback form those that have tried the preliminary 
> > release of 
> > these changes, we are comfortable with adding them as 
> > standard K3 features.
> > 
> > Please note that the last item, the IF Output Buffer Gain mMod, is 
> > slightly different than the similar N8LP mod some have been 
> > performing 
> > on their K3s independently. We determined that only one value 
> > needs to 
> > change to implement the gain increase for the IF output. We 
> > are changing 
> > R8 from 1K ohms to 13K ohms.   (Those that have made the N8LP mod may 
> > also leave it as is.)
> > 
> > Also, we are releasing new beta f/w today, MCU 3.27/DSP 2.24. This is 
> > already available on the web page at:
> > 
> > http://www.elecraft.com/K3/k3_software.htm
> > 
> > This release includes:
> > 
> >     *ADDITIONAL NOISE REDUCTION (NR) IMPROVEMENTS.
> >     *AUTONOTCH depth improved.
> >     *SHIFT=.01 FIXED WITH LOW SIDETONE PITCH (300 Hz).
> >     *VFOs NOW TUNE DOWN TO 490 kHz.
> > 
> > We never sleep in Aptos! :-)
> > 
> > 73, Eric   WA6HHQ
> > 
> > Roy Morris wrote:
> > > I would like to know if is the intention of Elecraft to incorporate 
> > > the K3 AUTOMATIC FRONT-END PROTECTION mod and the K3VFO 
> > TUNING NOISE REDUCTION mod in future PC boards.  If so, I 
> > plan to install these mods in my K3s.  Roy Morris  W4WFB
> > >   
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