Re: Transmitter gain calibration

Colin Smithers

How are you measuring power output?

I have set up three K3s now and have found the following:

- my measurement of power was all over the place until I calibrated my power meters with against a professional one - HP438: my Bird was 20% out, slug cal was off with a very noisy cal pot. All my various power meters of various ages were out to some degree. Better agreement now.

- Out of the box the K3s are set to deliver higher power than indicated, around 10-15%.

- power can be set right at  half power or full power (i.e. 5/50, or 10/100) but not both as the power measurement is not quite linear

- Low voltage limits power output, and dodgy power cables/ connectors can achieve this

Don’t know if this helps

73, Colin G4CWH

On 6 Jun 2020, at 02:36, Robert W5AJ via <woodr90@...> wrote:

K3/100 -> noted that K3 was indicating 50watts output when the RF power was set at 100watts.

opened the K3 utility ( and started the Calibration test

5 watt test, failed first band - 160 - gets to about 4 watts out and fails.

50 watt test, everything going fine until six meters, fails - couldn't get 50 watts out....

anything that I can tweak or check local or is the party over....

73 W5AJ

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