[TenTec] Orion Review By RSGB

Bill Tippett btippett at alum.mit.edu
Wed May 19 11:18:10 EDT 2004


W4PA wrote:

*************************************************************************
 >From the RadCom review:

 >5 kHz spacing dynamic range, 1 kHz roofing filter, 7 MHz band, 500 Hz DSP
CW filter
(they measured 20, 6, 2.4, and 1 kHz stock filters only):
91 dB

 >5 kHz spacing dynamic range, 2.4 kHz roofing filter, 7 MHz band, 500 Hz DSP
CW filter
94 dB

<SNIP>

 >"With the 1 kHz [roofing] filter, measurements showed it was possible to copy
an S1 signal with an interfering signal 90 dB greater only 500 Hz away.  This
is truly awesome performance."
*********************************************************************

         More contradictory information!  The above says 5 kHz IMD is 
better using
the 2400 Hz filter (94 dB) than the 1000 Hz filter (91 dB), yet the second
comment above implies the 1000 Hz is best (as ARRL, YT1NT and Sherwood have
all reported).  Scott, did you possibly transpose RadCom's data?  If not,
these measurements contradict Sherwood's which were first reported in March
by W0YG (terrible format but I attempted to redo it):

http://dayton.akorn.net/pipermail/orion/2004-March/000309.html

Dynamic Range Test

@5 KHz     @2 KHz       @1 KHz  Filter

96dB      95dB         89dB             2.4 KHz
96dB      94dB         93dB             1.0 KHz

         Will the REAL data please speak up now?

                                         73,  Bill  W4ZV



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