Hi - I succumbed at Dayton and ordered a new Orion II. To be truthful I have
been studying the 7800, 9000 and Orion II literature pretty seriously for a
while; the tipping point was Rob Sherwood's updated posting of receiver
performance plus my own distrust of Yaesu build quality of late.
Since I have to wait until June 10 at least for the new O2 to be shipped I
have had a chance to just about memorize the manual.
The question - the manual recommends using a moderately wide CW roofing filter
(1 khz) for general, non crowded, weak signal dx - due to increased loss with
narrower filters. In the QST review of the original Orion, dynamic range
decreased with the narrowest roofing filters - the thought being the
compensating amplification was the culpret. Since Sherwood listed the same
95db dynamic range at 1 khz using the new 4 pole 300 hz filter as it did at 2
and 20 khz with wider filters is the manual's recommendation still valid?
- What is the narrowest filter for which there is no compensating amplifier?
- Would that be the recommended filter roofing filter for general weak signal
dxing?
- With the new 4 pole roofing filters does it make any difference?
Thanks much - anxiously awaiting the hardware. I have a couple of other
questions related to amp interfacing and PSK / FSK, but I'll wait with them.
Keith - AC9s
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