[TenTec] FS: Orion 600 Hz Filter

Bill Tippett btippett at alum.mit.edu
Mon May 21 10:56:36 PDT 2012


Cleaning my shack and I found my prototype 600 Hz roofing filter for the
original Orion.  This was the first prototype of what later became the
Inrad #762 and eventually led Ten-Tec to redesign the front-end for Orion
II.  This is a hand made unit with exposed crystals like original Orion
4-pole filters (photo in link below).  It also has the distinction of being
the actual filter used by Rob Sherwood in his comments below, which were a
vast improvement over ARRL's initial results using the optional 500 Hz
filter (comparison below is to the stock 1 kHz 4-pole):

* >*
 * > At 5, 10 and 20 kHz, there is no significant difference between the*
 * > stock 1.0 kHz Ten-Tec filter and the Inrad filter.*
 * > At 2 kHz spacing, the improvement is on the order of 6 to 7 dB.*
 * > At 1 kHz spacing the improvement is closer to 10 dB.*
 * > There is some strange hysteresis of a couple dB, as you change the
level*
 * > around.  The IMD does not act exactly as one would expect.*
 * > I am guessing the digital AGC is doing strange things, causing the*
 * > hysteresis.*
 * >*
 * > The insertion loss of filters #2 and #3 are identical to the Ten-Tec
1.0*
 * > kHz filter.*
 * >

*http://users.vnet.net/btippett/inrad_.htm  (photo and more background)

Please reply direct...best offer over $50 ships Saturday by Priority Mail.

73,  Bill  W4ZV*
*


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