[Elecraft] Wattmeter for K3s Calibration

[Ron D'Eau Claire]

For the Transmitter Gain calibration, all you need is a decent dummy load.
The LP-100A is not a dummy load. My 20-year old inexpensive MFJ dummy load
does a good job for that. (But note it has never been abused, such as
running power into it until it gets hot or smells.) A well designed dummy
load will have very little reactance from stray capacitance or inductance.
That leaves only the value of the resistive element, which you can check
with your DMM. It's the resistive element that is most susceptible to damage
from overheating it, just like any other resistor.  

For calibrating the wattmeter in your K3S beyond the factory setting,
whatever makes you happy is perfect. There is no operational or performance
advantage to "improving" the factory settings. The LP-100A claims 3% power
display accuracy which is much better than most (if the claims are true).
For example, the ARRL lab is quoted in their manual saying "They specify
their measurement error for power as +/- 5%, and for PEP power, +/- 8%."
Note the +/- meaning the power error may vary by 10% for constant carrier
and 16% PEP. Those are much more typical values for good, even lab quality
power measurement equipment.   

73, Ron AC7AC 

-----Original Message-----
From: Elecraft [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Clay
Autery
Sent: Tuesday, April 26, 2016 6:50 PM
To: Elecraft Reflector
Subject: [Elecraft] Wattmeter for K3s Calibration

Would the LP-100A meet the accuracy/precision requirements to do the power
cals outlined in the K3s Manual?

If not, please supply recommendation for one that will do the job
adequately.

Thanks!

--
______________________
Clay Autery, KG5LKV
MONTAC Enterprises
(318) 518-1389

______________________________________________________________
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 Message
delivered to ron at elecraft.com