[DSP-10] EMRFD Code for 17m Xcvr

Tue May 4 17:22:16 EDT 2004

Hi Bob....thanks for the clarification.

I tried to recall the inherent differences in the two boxes.  I realized
after sending out the mail that indeed the DSP-10 looks much more like a
traditional multi-IF-stage receiver, with only the final IF to audio being
peformed in quadrature.  Like you said, there is no quadrature RF VFO to
have to re-correct.

I have to build a Hilbert transform sometime to re-iterate that they
actually work.  For some reason, I've always been skeptical!

I'll go back and re-read that chapter....if I can get my work-copy of EMRFD
back from my co-workers.  I brought it in so a peer could take a look at the
DSP chapters (yes, for work-related reasons!), and now I can't get the book
back.  I'll have to see if the Beaverton warehouse could lend me a 3rd copy.

73.  Enjoy your time away.

	Roger

Roger Hayward
ARS KA7EXM
Email:  [email protected] 

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of [email protected]
Sent: Tuesday, May 04, 2004 9:10 AM
To: [email protected]
Subject: RE: [DSP-10] EMRFD Code for 17m Xcvr

Hi Roger and all,

Yes, but...

The DSP-10 does all the I-Q mixing and phasing work in DSP, with the 15
kHz I-F signal in. The 17-meter rig uses hardware mixers and does the rest
in DSP. The biggest difference is that the 17-meter rig has provision for
vector correction of the hardware mixer errors, and this is fun stuff! 
The DSP-10 does not have this since there are no significant mixer errors
in the first place.

Also, the 17-meter rig was kept as simple as possible to make it easy to
play with. I'm not sure that claim can be made for the DSP-10  ;-)

The 17-meter rig works really quite well, but some work is needed to
improve the receiver dynamic range. I was going to play with that some
day, but if someone else is so inclined, I would be happy to provide
assistance. Meanwhile the rf gain is the solution, and that works fine.

I'm going to be gone for a couple of days, so if I don't respond to
replies, I'm not ignoring you!

73,
Bob  W7PUA

> (....isn't the DSP-10 a phasing receiver?)
>
>
>
> Roger Hayward
> ARS KA7EXM
> [email protected]
>
>
> -----Original Message-----
> From: [email protected] [mailto:[email protected]]
> On Behalf Of [email protected]
> Sent: Tuesday, May 04, 2004 6:48 AM
> To: [email protected]
> Subject: Re: [DSP-10] EMRFD Code for 17m Xcvr
>
> Hi Lyle,
>
> Thank You for posting Bob Whelan's code.
>
> It will be interesting to experiment with a DSP phasing receiver
>
> 73,
>
> Bob Johansen WB2SRF
>
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