[DSP-10] Using dspx with dsp10

[dsp-10@mailman.qth.net]

Anyone succesfully got a dsp-x interfaced to the dsp-10?

I have; but it only works "sortof", as the following explanation details:-

The DSPX is hooked up as per the diagram on the dspx web site to the dsp10
board

The dsp-10 board was previously working perfectly with the ez-lite dsp

I downloaded it with uhf3.exe dated 05 27 03 using ezfast (from the dsp-x
web site)

i am using uhfa.exe dated 01-22-04 as the front panel

If i launch uhfa with no uhfa.cfg file it receives and transmits

With no rf input I get the following signal levels against rf gain

RFG    dbm
100    -145
94    -138.9
88    -132.6
82    -127.1
76    -120.8
70    -115.1
64    -108.8

which is going the wrong way?

Also on a loud signal, ssb or cw,  received with rfgain=100 (received
signal =-75dBm the front panel says) it is so distorted as to be
unreadable. If I change to rfgain = 94 it is fully understandable, but it 
says received signal =-72dBm (lowering rf gain increases signal level?)

On transmit the locals complain that the FM is too wide (especially
compared to the ez-lite board). This is at all Mic gain settings that
produce deviation. SSB is ok, just "sounds electronic"! The DSPX board
gives around 0.5V peak to peak on a good whistle on SSB, on FM it gives a
constant amplitude (as one would expect on FM) of 3.2V peak to peak. On
the debug scale on the uhfa screen, the A/D level meter just hits red on
both FM and SSB. On SSB the  D/A level meter just hits red on speech
peaks; on FM every bar, including all the bars is lit and doesnt vary. The
RF level is correct, hitting 30mW. Comparing the o/p spectrum of the DSP10
transceiver on my HP8536E against both my IC706 and VX1R it does fill more
bandwidth.....i dont have a deviation meter

If i exit uhfa to dos of course it writes a uhfa.cfg file

If I then launch uhfa again i get No transmit on any mode...(the LED on
the RF board does come on on TX) the locals dont get to complain about
deviation!

However the need to change RF gain to 94 to hear a loud signal dissapears,
the loud signal is perfectly copyable at rfgain = 100, even though the
input signal level is still the same!

With no input i get the following signal levels against rf gain
RFG    dbm
100    -194
94    -188
88    -182
82    -176
76    -170
70    -164
64    -158

Which probably breaks Boltzmanns KTB formula!

If i exit uhfa to dos of course it writes the uhfa.cfg file again and on
restarting UHFA i go back to scenario 1:-

((With no rf input i get the following signal levels against rf gain

RFG    dbm
100    -145
94    -138.9
88    -132.6
82    -127.1
76    -120.8
70    -115.1
64    -108.8

etc

And so the cycle repeats forever

Anyone any ideas on whats happening?

Dave

ww2r