PRO2004.6
Part 3/4

                         Taping Facility

     A tape recorder can be connected to the TAPE phono jack
     on  the rear panel, which provides 600 mV of audio at a
     10,000 ohm impedance.  In addition to  a  rear  mounted
     external speaker jack, there is a headphone jack on the
     front of the scanner.


                        Basic Performance

     To evaluate sensitivity, the $400 PRO-2004 was compared
     with  a  $950  ICOM  R7000  and  a  $300 UNIDEN/Bearcat
     800XLT.  Since a signal generator was not used, quanti-
     tative   measurements  could  not  be  made.   Instead,
     various antennas were switched between radios,  signals
     from  stations  were  compared  by ear, and the results
     tabulated.

     Simply put, the PRO-2004 is sensitive enough  to  allow
     one  to  hear what needs to be heard, and not so sensi-
     tive as to be overloaded by  strong  signals.   On  850
     MHz,  signals  were  readable  on  the  PRO-2004  which
     couldn't even be detected on the R7000.

     Although the 800XLT is the most sensitive radio of  the
     three  tested, it suffers from images and overload much
     more than the PRO-2004 or R7000.  The PRO-2004 has a 10
     dB  attenuator, operable by a slide switch on the rear,
     but its use has been unnecessary thus far.

     The up conversion design of both  the  ICOM  and  Radio
     Shack  units allows use of a very high IF (intermediate
     frequency), which  helps  avoid  image  problems.   The
     PRO-2004 owner's manual doesn't list the IF frequencies
     directly, but a good guess is that the  first  two  IFs
     are 610 MHz, 70 MHz.  The third IF looks something like
     455 KHz when using AM or NBFM,  and  perhaps  10.7  MHz
     when the WBFM mode is selected.

     The PRO-2004 is slightly more selective  on  NBFM  than
     the  800XLT.   WBFM selectivity is rated at about twice
     as wide as the ICOM R7000.

     The audio output quality is good, although it seems  to
     lack  the  punch  of the 800XLT audio.  The top mounted
     speaker directs the sound at the ceiling, but adding an
     external  speaker  would allow the sound to be directed
     at the user.

     Unfortunately,  the  audio  level  of  AM  signals   is
     somewhat  below  that of NBFM signals, requiring a dif-
     ferent setting of the volume  control.   When  scanning
     both  AM  and  NBFM modes, one has to find a compromise
     position of the volume control.

CONT IN PRO2004.12