[Elecraft] K3s - 80W on 160

[John Kaufmann]

I had the same issue with my K3S.  I was seeing 80W maximum on 160 and it
would not drive my AL1200 to full power (1500W).  Redoing the power
calibration did not fix the issue.  

 

Elecraft Tech Support told me that my K3S was within spec but that
increasing the power supply voltage could yield more power output.  I ended
up increasing my supply voltage from 13.8 volts to 14.5 volts and was able
to get 90W out, which was a bit of an improvement.  There is a trim pot
inside my Astron RS-35M supply that adjusts the output voltage.  

 

73, John W1FV

 

 

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Message: 10

Date: Sat, 17 Dec 2016 00:27:48 -0500

From: "Gary Smith" <Gary at ka1j.com>

To: elecraft at mailman.qth.net

Subject: [Elecraft] K3s - 80W on 160

Message-ID: <5854CCD4.7315.16D88C8 at Gary.ka1j.com>

Content-Type: text/plain; charset=US-ASCII

 

I usually don't run barefoot at 100W and 

don't drive my amp with more than around 

50W. Tonight when I tried running at 100W 

on 160 I was surprised to find it only 

putting out 81W. It puts out incrementally 

till 81W and then even though I can adjust 

the power so it reads 100W on the K3s LCD 

bar and numerical display, the watt meter 

in the P3 and the LP-100A both show the 

wattage stopping at 81W.

 

With the ATU in or out it gives 81W out on 

160, SWR is 1.28 

 

All other bands except 6M give around 98W, 

6M gives 87W

 

Any ideas what might be causing the lower 

output on 160?

 

Thanks & 73,

 

Gary

KA1J