Calibrate Diamond SX20C cross needle SWR meter

[9W6VX]

I have a Diamond SX20C cross needle SWR which needs calibration. Both needles at rest are not at the minimum level (0).

How can I calibrate it?

Appreciate your kind replies.

Thanks.

[K7KBN]

I'm not familiar with that particular meter, but from the pictures available online, I'd say you will have to open it up and look at the rear of the meter movement enclosure for two small adjusting screws, which you carefully adjust for a zero pointer indication.  My Daiwa cross-needle meters all have the adjusting screws right on the front panel.

[9W6VX]

Thanks for your reply.

Will check it out and revert back if still negative.

73 de 9W6VX

[WJ7S]

If you open the meter there are calibration pots for the high and low power and swr but I cannot find any instructions anywhere on how to calibate

[K7KBN]

If you open the meter there are calibration pots for the high and low power and swr but I cannot find any instructions anywhere on how to calibate

You'll need 1:1, 2:1, 3:1 dummy loads (very close in resistance and capable of handling the transmitter power).  You'll also need an RF wattmeter that has at the very minimum a 4:1 ratio of maximum error compared with the meter you're calibrating. Meaning that if the manufacturer of your meter says it's plus or minus 10%, the standard must be plus or minus 2.5% or better.

Dummy loads and wattmeter must themselves be calibrated (otherwise you don't know what's right and what's wrong). 

[AC5UP]

.................and then you notice this thread is from 2005.

Not that there's anything wrong with that.