Re: Procedure to measure rf watts

Larry McDavid

Well, yes, but the whole point of interchangeable Bird slugs is to select one that measures your power near the top of the meter scale. That's one reason so many different slugs are available. You would never select a 10 Watt slug to measure a 1 Watt power. It is difficult to beat the ruggedness and reliability of the Bird watt meter.

When transporting the Bird watt meter, the meter movement should be damped by shorting its meter coil. That can be accomplished by removing the slug and inserting the solid aluminum slug provided. But, it is far easier to just rotate any slug 90° but leave it in-place. That simple solution is not always known...


On 5/23/2019 6:06 AM, Chuck Harris wrote:
The venerable bird wattmeter is really quite awful in terms of
accuracy. At its rated best, it is +/- 5% of full scale.
So, if you are using a 10W slug, its accuracy band is +/- 0.5W.
Ok, if you are measuring 10 W, but it gives you a 50% uncertainty
if you are measuring 1W.... 20% if you are measuring 5W.
Your scope can do much better than that.
-Chuck Harris

Dennis Tillman W7PF wrote:
Hi Randy,
How about a Bird Wattmeter. They are the first thing a ham thinks of ...
Best wishes,

Larry McDavid W6FUB
Anaheim, California (SE of Los Angeles, near Disneyland)

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