Kudos to Chester!
Even though we would all like to believe that that least significant
digit all the way to the right of our displays is that accurate, a small
bite of a reality sandwich is always a good thing.
73 de Jeffrey Modlin
KD4ZNC in Coral Springs, Florida USA
-----Original Message-----
From: tentec-bounces@contesting.com
[mailto:tentec-bounces@contesting.com] On Behalf Of Alderman, Chester
Sent: Tuesday, March 04, 2003 11:10 AM
To: 'tentec@contesting.com'
Subject: RE: [TenTec] Argonaut V ARRL Review 3rd and 2nd IPs ?
"You can't measure a signal to
millivolt accuracy if your test instruments are +- .1 volt in accuracy."
I think this is a GREAT point for all of us hams to understand!
There is now a discussion ongoing about the frequency readout to 1Hz,
but
most of us don't yet grasp the concept that we are buying and using
amateur
radio equipment and NOT a precise frequency counter. Really precise
frequency counters, power meters, test equipment are calibrated to
standards
traceable to NBS, on a quarterly requirement. Amateur radio equipment
are
not, and are not required to be, calibrated to ANY standard.
Why do we expect our ham gear to be within 1Hz accuracy or
within
.001 watt accuracy?
An accurate power meter, for instance, cost around $4000. Then
it's
accuracy is only guaranteed if it's calibrated quarterly to a NBS
traceable
standard.
We hams test our amateur gear by EAR! And we have no real need
to be
concerned about +/- 1Hz or +/- .1 watt.
Tom/W4BQF
-----Original Message-----
From: KD5NWA [mailto:KD5NWA@cbayona.com]
Unfortunately just because you use the same method, doesn't mean the
results are any good. For example if the testing methods because of
using
different mixing methods generates it's own IM into the picture, it will
greatly affect the results. A radio with lousy IM distortion, will show
up
bad, but a radio that has great specs, will suffer terribly, making the
user think that the better radio is really not that much better, when
the
truth is that there is a huge difference. You can't measure a signal to
millivolt accuracy if your test instruments are +- .1 volt in accuracy.
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