From randy_ware%nwmail
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From: randy_ware%nwmail
Newsgroups: alt.radio.scanner
Subject: A Pro 2021 Mod
Date: 28 Aug 1993 19:08:07 GMT
Organization: NCPA/University of Mississippi
Lines:23
Message-ID: From: randy_ware%nwmail
>Subject: A Pro 2021 Mod
>Date: 28 Aug 1993 19:08:07 GMT
>This is a speed-up mod for the slow 2021 that does work. It will increase
>the scan speed to about 11 channels per second. It has no effects on the
>delay time.
>
>Unplug the radio, remove the 9volt batt.
>
>Remove the upper case, by removing the four screws on both sides of the
>outer case, as well as the one screw on the rear apron of the radio which
>fastens the upper case to this surface.
>
>Lift the top case section and unplug the white plastic two conductor
>speaker plug, allowing removal of the upper case entirely.
>
>With the scanner sitting upright and facing you, locate resistor R-147 (a
>39k-ohm resistor to the left-front of the main board-almost behind the
>vicinity of the LCD display). Snip the leads at the resistor body with a
>pair of wirecutters to leave as much of the existing leads as possible.
>
>Solder a 15K-ohm resistor to those remaining leads.
>
>I found this mod in Monitoring times and have done it to several Pro 2021
>scanners and have seen no negative drawbacks to it.
>
I want to add one more note to this mod, Overall what you are doing is
adding 15k-ohm resistance to R-147. For a total resistance of 54k-ohms.
YOU ARE NOT REPLACING THE 39k WITH 15K.
total of
-----------------------------------------------------
I recently aquired a realistic Pro-2021 and since you do not have
the cellular mod for this posted i thought i would send it over.
Its not that hard to figure out if you have done a mod before.
To restore 68MHz to 88MHz and 806MHz to 960MHz just find the row of diode
slots on the lower left of the scanner and remove the only two diodes
there which are D44 and D45. tada
SOURCE: The QRZ Windows Ham Radio CDROM |
