[Amps] Time for New Power Meter

[Dr. David Kirkby (Kirkby Microwave Ltd)]

On 20 April 2015 at 19:01, Colin Lamb <k7fm at teleport.com> wrote:
> I have a number of wattmeters, but have always used the Bird or Dielectric as the gold standard.  One model allows you to switch power levels.
>
> For one station, I purchased a used Bird Hammate and added a PEP adapter to it.
>
> 73,  Colin  K7FM

Why would anyone use a Bird as a gold standard? The specification on
them is an uncertainty of 5% of FSD, but in practice they are rarely
that good - even new elements.

I bought an element new from Aspen Electronics who are a Bird
distributor. I took it into where I worked (a national calibration
lab), and it was out of spec the day I got it. I took it back, said I
was only interested in performance at 432 MHz, and they adjusted it.
Then it was ok.

If all you want to do is get an approximate idea of power, then a Bird
is good. But it is never a gold standard. I'm measured 100's of
elements, and know they they rarely meet 5% of FSD when new. You can't
even guarantee 10% of FSD, although most will meet that.



Dave, G8WRB