That's exactly how I'm looking at it. For the normal tube
superhets I'm used to, I'd be looking for the most narrow, lowest noise, highest
"Q" frontend I could get my hands on ...and it would probably
be manually tuneable. For this SDR "direct conversion" stuff, with "fixed"
pluggable) BPFs, I want to try some additional things and see what the
"down side" is. I already have a pluggable BPF on my SR-40 and plenty of red
cores. If it does not work, I'll go back to single band filters but I'm amazed
just how well the existing 6.5-12Mhz BPF works, that's pretty broad.
The biggest problem is getting rid of all the "spurs" off the DDS
73 Kees K5BCQ
----- Forwarded Message -----
Date: Tue, 29 Nov 2005 21:41:23 -0600
Subject: Re: Fw: Re: [softrock40] Re: My Dual-Band Version
The QSD detector doesn't stop detecting at other
the Quadrature clock, it can receive at multiples and
it's up to the filter to keep them out. So if it's too broad
pick up all sorts of goodies that aren't where you think they
On the other hand it won't explode or anything nasty, if it doesn't
work out you can always undo it.
At 07:03 PM 11/29/2005, you
>With the SoftRock performance I see here using the "pretty broad"
>stock 6.5Mhz - 12Mhz Bandpass filter on the SR-40, I wonder how an
>even broader BPF filter would do ...say 3Mhz - 16Mhz, or 1.8 - 30
>Mhz for that matter ?? The most serious signals in this area are the
>local AM and FM stations. I think I'll build one and
>73 Kees K5BCQ
>softrock40" on the
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"I fail to see why doing the same
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same results every time is insanity:
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