Here is one dummy version. Receiver dynamic range was a periodic check that
was made to a FAA long range radar receiver (part of ARSR-1D). The check
was made in the following manner. A signal generator was set to the
receiver frequency. The generator was set up for pulsed output it was
synced with the radar trigger. The timing was delayed so that the pulse was
displayed on an oscilliscope looking at the receiver's detector output. It
was usually displayed beyond the sentisitivity time control (STC) or STC
turned off at the receiver. STC is similar to AGC except it is variable
with time....greatest at range zero and decreased with range until no longer
controlling the gain at long range.
Now this what was termed dynamic range: While observing the pulse at a low
level, the generator output was slowly increased and the pulse also
increased. At some point in increasing the generator the observed pulse
would reach a level at which further increase in the generator would not
increase the pulse or what we called the "limit" value. This poing would be
noted and then the output of the generator would be decreased until the
pulse would be reduced so that it could barely be discerned from the
surrounding noise (called grass) this level was recorded. The difference of
the two readings was the dynamic range of the receiver. There were two
receivers that were checked, one called "normal" the other called "MTI"
(Moving Target Indicator) The MTI used a phase detector producing bi-polar
video output, while the Normal receiver used a simple amplitude detector.
So Scott, I guess dynamic range could be called, "the range of signal level
that there is a useful output from the receiver" I am sure there are other
non-dummie explanations that could "provoke more thought"
73, Jim, wd4air
From: CHRSAM195@aol.com
To: tentec@contesting.com
Subject: [TenTec] Receiver Specs
Date: Tue, 7 Jan 2003 17:27:25 EST
Where can I find a " Dummies" version or explanation of the " Dynamic
ranges"
and other associated terms regarding receiver specs. Thanks and 73's Scott
WB2NYM
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