[DSP-10] DSP-10 with DSPx problems and solutions

[Edward J White]

Hi Gang:
I would like to have a copy of the changes Got the kit but have to spend 
some Time putting it together. My assembly manual  and part supplied is Aug 
28 2000?
Ed
WA3BZT

----- Original Message ----- 
From: "Peter Horbaczewskyj" <peter at hotkeys.co.uk>
To: "Discussion of DSP-10 2-meter transceiver" <dsp-10 at mailman.qth.net>
Sent: Monday, January 24, 2005 11:16 AM
Subject: RE: [DSP-10] DSP-10 with DSPx problems and solutions


> Hello Hermann,
>
> I have just purchased a partially completed DSP-10 and a DSPx arrived in 
> the post over the weekend.
> As I still have to wire everything together I wondered whether you would 
> make your notes available. It would certainly be interesting to see what 
> changes you have made to the wiring of the units (compared to the QST 
> articles) and also to try and match signal levels for the various 
> amplifier stages. It seems that there are still many tweaks that can be 
> implemented for this project to improve its overall performance, 
> especially with the extra processing power of the DSPx unit.
>
> Now to order the remaining components!!
>
>
> 73 and regards,
>
> Peter G4ZXO
>
>
> -----Original Message-----
> From: DC9UPGermany at aol.com [mailto:DC9UPGermany at aol.com]
> Sent: 22 January 2005 10:38
> To: dsp-10 at mailman.qth.net
> Subject: [DSP-10] DSP-10 with DSPx problems and solutions
>
>
>
> Hello  DSP-10 friends...I just have finished the third DSP-10. Two of them
> were with  the original EZ-Lit-Kit and worked out very fine. I made a lot 
> of
> changes  (including the known changes by the Assembly Manual) to all three 
> DSP-10
> projects and noted them down for whom it may concern.
> The  third one now includes the new DSPx processor and it’s also a fine
> instrument on  receive. I can not detect any birdies over the range 144 to 
> 146 MHz
> (this  range is used in Europe!) and maybe this has to do with  the 
> shielding
> technique I used.
> First:
> The  top-cover of the DSPx box has extra lids with 14 screws around to 
> hold
> them  down to the box. The box should be "watertight".
> Second:
> I  used very thin white shielded Aircraft-wires for most of the back-plane
> connections, especially the once which distribute signals. Besides  this, 
> I
> used fine semirigid cable for the LO oscillator signals which can be 
> soldered
> directly with the outside to backplane.
> Third:
> The  cable routing inside the box and outside the box is done in a very
> different way compared to the original project.
> I  also build the DSP10 PCB not the way the assembly manual and the
> associated  parts layout show. The building process was done by 
> "Group-building" and
> testing each group of circuits after soldering. By this way problems can 
> be
> traced down easy and when ready with all groups the DSP-10 works right 
> away.
> The  main changes I made are in the LO parts and their amplifiers. Their
> inter-stage gain and levels must be corrected not to overdrive the 
> following
> amplifiers (MSAs) and deliver the right undistorted level to the  mixers.
> All  changes are documented down here.
> ------------------------------------------------------------------------------
> --------------------------------------
> The  only program working after the download from the PC to the DSPx is 
> the
> one from  Bob on his website. 
> (_http://www.proaxis.com/~boblark/uhf3x_25.zip_
> (http://www.proaxis.com/~boblark/uhf3x_25.zip) )
> No  other version will work with the DSPx !!
> Download  is done by the EZFast Loader with the command line:
> Ezfast L 1 uhf3x.exe  G
> The  L stands for loading with 9600 b/s; no fast loading with an "M" is
> possible.!!
> The  1 stands for the COM port, 1 in my case.
> So  far so good. The DSPx seems to work as good as the old EZ-Kit. Good 
> work
> done by Lyle.
> Now  I run into the first (maybe small) problem.
> On  transmit the Codec in the DSPx part can easily overdriven by the
> Microphone  input in all modes, FM, USB, LSB etc.
> SSB  sounds very bad and it does FM-ing and after scoping around and 
> looking
> to the  output signal with an SA, I could see that the carrier is 
> wandering
> when  overdriven and has some FM on it.
> Bob  came around this problem in the original EZ-Kit and installed a
> "Clipper".
> But  this clipper does not work properly with the DSPx.!!!
> I  think it must be reworked to match the new CODEC.
> One  more remarkable problem occurred to me.
> Changing  the MIC gain from 61 to 60 completely shuts off the clipper 
> !!??
> After  shutting down the program and the DSP-10 and restart again it will
> work  again....curios..???
> Did  somebody else experience this too??
> Best  73 and happy work with this outstanding TRX DSP-10...I am lucky with
> it.
> Hermann,  DC9UP
> E-Mail:    _DC9UPgermany at aol.com_ (mailto:DC9UPgermany at aol.com)
> (mailto:DC9UPgermany at aol.com)
>
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