[Elecraft] K3 Power Problem ??

[Jim Harris]

Hi,

Exactly 100 watts set on K3.  Measured about 90 watts out on two external watt meters.  One on an MFJ antenna tuner and the other is a high end MFJ power meter.  They agree within a couple of watts near 100 watts measured.

Have a good day and 73.

Jim, W0EM




> From: W5OV at W5OV.COM
> To: w0em at q.com; elecraft at mailman.qth.net; gary at elecraft.com
> Subject: RE: [Elecraft] K3 Power Problem ??
> Date: Fri, 4 Dec 2009 21:51:35 -0600
> 
> Jim,
> 
> 23 to 24 amps on transmit? The manual says you should have 17 to 22. At 14v
> it sure sounds like you're running a lot more than 100w out. 
> 
> How are you measuring the output?
> 
> W5OV
> 
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net
> [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Jim Harris
> Sent: Friday, December 04, 2009 7:46 PM
> To: Elecraft Email; Gary Elecraft
> Subject: [Elecraft] K3 Power Problem ??
> 
> 
> Hi Folks,
> 
> When doing RTTY at 100 watts a high current warning flashes in the VFO B
> display area and RF power is automatically cut back to about 60 watts.  SWR
> is about 1.1:1 or there abouts; nothing approaching 1.5:1.  I have found
> there is 0.6 volts drop in the Elecraft supplied power cable (Power Poles
> are soldered) and about 0.2 volt drop between my power supply and the output
> of the Rigrunner.  It's between the power supply and the K3.  Voltage at the
> radio drops to 13.2 vdc and current is 23-24 amps on transmit.  Under that
> load the voltage at the power supply drops 0.01 volts.  I run the power
> supply (it's variable) at 14.0 volts at the supply.  It's a 40 amp power
> supply.  I have a popular off shore rig that has no problem with the
> existing power setup.
> 
> In reading the Supply/Voltage Current specifications on page eight (8) of
> the Owners Manual I find it recommends  "When using reduced supply voltage
> (<12volts), power output should be reduced (e.g. 70 W at 11 V).  Further,
> "For best results, use the supplied 5 foot (1.3 m) power cable."  Those two
> statements appear to be in error when applied to my radio.
> 
> My K3 appears to be overly sensitive to voltage and current.  The only
> adjustment I can locate that might relate to this is the menu CONFIG:ADC REF
> entry. However, I seriously doubt it will have any impact on this as this
> appears to be a serious error and adjust appears to be for fine tuning at
> best.
> 
> I certainly would appreciate any ones constructive input on this situation.
> I could appreciate knowing the gauge of the supplied cable....I'm hoping
> that doubling or tripling the size might help.  But, that seems to be a
> bandaide rather that eliminating the root cause.
> 
> Thank, have a good day and 73.
> 
> Jim, W0EM
> 
> 
>  		 	   		  
> ______________________________________________________________
> 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
>