On Fri, Mar 25, 2005 at 09:28:04AM -0800, R. Measures wrote:
> Hewlett Packard also made directional couplers. If the loss factor in
> the forward pickoff arm of the coupler was known, power measurements
> could extend considerably upward.
True, in fact we did use directional couplers as well as attenuators. I
don't recall HP having coaxial couplers until later, but we used
their waveguide couplers as well as coax units made by Narda and
several others.
Bob, N7XY
>
> On Mar 25, 2005, at 8:07 AM, Bob Nielsen wrote:
>
> >On Fri, Mar 25, 2005 at 10:48:53AM +0000, David Kirkby wrote:
> >
> >>
> >>1) In response to Gary Smith I said " I suspect Bird use Calorimeters
> >>for internal use, but would not use them to calibrate each and every
> >>element they sell, as the method is too time consuming."
> >>
> >>2) "Another big problem for amateur power measurement would be line
> >>voltage variations. Since any such measurement by Calorimetric
> >>methods
> >>will take 10's of minutes at least, there needs to be a way of keeping
> >>the RF and DC power constant."
> >
> >The Hewlett-Packard Calorimeter I used at Hughes Aircraft in the early
> >1960s was much faster than that. It didn't take much longer to make a
> >measurement than using a bolometer-type meter--not instantaneous, but
> >perhaps several seconds. I recall it would measure up to 10 watts,
> >which was sufficient for the measurements I was making, but higher
> >power
> >levels would still require the use of attenuators.
> >
> >73, Bob N7XY
> >
> >_______________________________________________
> >Amps mailing list
> >Amps@contesting.com
> >http://lists.contesting.com/mailman/listinfo/amps
> >
> >
>
> Richard L. Measures, AG6K, 805.386.3734. www.somis.org
>
>
>
--
Bob Nielsen, N7XY n7xy (at) n7xy.net
Bainbridge Island, WA http://www.n7xy.net
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