[Premium-Rx] Fw: WJ-8711A-3 Strange behavior...

[ka5fun]

Gentlemen,
 
As previously mentioned, I recently purchased a WJ-8711A-3 receiver. 
When it arrived, I discovered that it is unusual in several ways, and has
a rather strange problem.
 
Serial #:                                 14
 
Front Panel EPROM:            871Y 
                                             A1A1U3 
                                             1.21
 
DSP EPROM:                       871Y
                                             A2 U56
                                             05.00.00
 
Internal Control EPROM:      8711A-3
                                             A2 U12
                                             01.00.00
              
The DSP PCB has the following numbers printed on it:
08 95 6259 -01
14632ASSY
797214 A
 
OBSERVATIONS:
1- All detection modes seem to work normally except for USB and LSB.
2- All selectable IF Bandwidths seem to work normally.
3- All front panel buttons seem to work normally.
 
PROBLEMS:
1- Signal Strength Meter reads approximately 8 dBm low
2- No Notch Filter function available when pressing the "Special
Functions" button?
     (Is this because of the inclusion of the FSK detection mode?)
 
QUESTIONS:
1- What are buttons "A" and "B" for? (see fig. 1)
2- Detection Mode button physically not centered on the front panel? (see
fig. 2)
3- The Main Tuning Knob is rather stiff - how can I remove and/or loosen
it?
     (No apparent holes to access the setscrew(s) on the side of the
knob)
 
PICTURES:
fig. 1 is at: http://img.photobucket.com/albums/v202/ka5fun/Fig-1.jpg
fig. 2 is at: http://img.photobucket.com/albums/v202/ka5fun/Fig-2.jpg
 
------------------------------------------------------------------------
--------------------
TESTS PERFORMED TO DEMONSTRATE THE ODD BEHAVIOR OF THE RECEIVER WHEN SET
To USB or LSB MODE.
------------------------------------------------------------------------
--------------------
 
TEST-1:
With the receiver set to ISB and tuned to 5.000 MHz, the resulting audio
frequency is constant, regardless of the selected IF Bandwidth.
Signal generator set for 5.001 MHz CW @ -50 dBm, Speaker set to USB,
audio output = 1,000 Hz.
Signal generator set for 4.999 MHz CW @ -50 dBm, Speaker set to LSB,
audio output = 1,000 Hz.
 
   -------------------------------------------
   ----- Receiver is performing normally -----
   -------------------------------------------
 
TEST-2:
With the receiver set to either USB or LSB, the resulting audio frequency
is incorrect and NOT constant when changing the IF Bandwidth.
Signal generator set for 5.001 MHz CW @ -50 dBm for USB and 4.999 MHz CW
@ -50 dBm for LSB
 
IF Bandwidth     Audio output 
     KHz                   Hz
--------------------------------------
0.900                      300
1.000                      400
1.100                      500
1.200                      600
1.300                      700
1.400                      800
1.500                      900
1.600                   1,000
1.800                   1,200
2.000                   1,400
2.200                   1,600
2.400                   1,800
2.600                   2,000
2.800                   2,200
3.000                   2,400
3.200                   2,600
3.600                   3,000
4.000                   3,400
 
Audio output should be 1,000 Hz regardless of the IF Bandwidth, and one
should not be able to select an IF Bandwidth greater than 3.2 KHz when in
USB or LSB mode...
 
   ---------------------------------------------
   ----- Receiver is performing abnormally -----
   ---------------------------------------------
 
My personal feeling is that it is likely to be a firmware problem and
that one or more of the EPROMS may either be flaky or of the incorrect
part number. 
Except for the USB and LSB modes the receiver seems to perform well.
 
To confirm my hunch, and possibly cure my receiver, I would like to get a
copy of the latest "standard" WJ-8711A EPROMs: 
Internal Control EPROM (A2U12) - Version 04.01.10 and DSP EPROM (A2U56) -
Version 04.02.07. 
 
Any help, advice, or suggestions would be greatly appreciated.
 
Best Regards,
 
Pete [KA5FUN]

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