[TenTec] FT-2000 Webpage

John T. Fleming W3GQJ at earthlink.net
Mon May 29 11:50:50 EDT 2006


If you look at the design of the Orion I, it is using "old design
techniques" of converting the first IF to 9 MHz.  It is much easier to make
a tight roofing filter at 9 MHz then one at 45 MHz.  A 250 Hz filter at 9
MHz would be the same ratio as a 1250 Hz filter at 45 MHz.  The Orion
sub-receiver has a 45 MHz IF.  That is why it can cover from the broadcast
band to 30 MHz.  The main receiver is only ham bands.  Otherwise you would
be hearing the IF frequency as you tuned 500 KHz to 30 MHz, and got to the 9
MHz area.

In the Orion I, the very tight filter is after the roofing filter.  An
amplifier state is switched in to make up for the losses.

The Orion II has all filters as roofing filters.

-----Original Message-----
From: tentec-bounces at contesting.com [mailto:tentec-bounces at contesting.com]
On Behalf Of G
Sent: Monday, May 29, 2006 10:32 AM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] FT-2000 Webpage

I still can't understand why Yeasu and Icom don't use close in filters like 
the Orion2???
I'll have to wait until the testing is done on this unit in close in 2KHZ 
dynamic range and where it falls in Rob's table.
I sold my ProII for the Orion-2 and the difference in operation is small but

there for me.

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