CALIBRATING A WATTMETER

[unit_399]

I have four wattmeters: two Transel Mark IIA, A Drake W-4, and a Realistic Digital. Using the same radio, jumper, and dummy load, each meter gives me a different deadkey reading. They vary from 3.2 watts to 6.0. Except for the Realistic, all of these meters are at least 20 years old. I want to calibrate them, but have no idea which one to use as a reference. Is there any way to do this without using another meter as a reference? I don't have an rf ammeter either. If there's no other way, I'll use the Realistic since it's only 3 years old and still in the box, or maybe take one of them to a Cal Lab here (if I can find one).

Any suggestions ?? Thanks in advance.

- 399

 

[Beetle]

You want to know which one to use as a reference? Easy. The one that reads closest to the actual applied voltage x current. You need a calibrated standard; anything besides that is a poor guess.

 

[MrSuburban]

I have four wattmeters: two Transel Mark IIA, A Drake W-4, and a Realistic Digital. Using the same radio, jumper, and dummy load, each meter gives me a different deadkey reading. They vary from 3.2 watts to 6.0. Except for the Realistic, all of these meters are at least 20 years old. I want to calibrate them, but have no idea which one to use as a reference. Is there any way to do this without using another meter as a reference? I don't have an rf ammeter either. If there's no other way, I'll use the Realistic since it's only 3 years old and still in the box, or maybe take one of them to a Cal Lab here (if I can find one).

Any suggestions ?? Thanks in advance.

- 399

Use an oscope for calibrating.