

Article 10541 of rec.ham-radio:
Path: philabs!prls!pyramid!oliveb!ames!haven!purdue!iuvax!silver!commgrp
>From: [email-masked]
Newsgroups: rec.ham-radio
Subject: Re: Another PRO-2004 mods request
Message-ID: <12600047@silver>
Date: 21 Mar 89 20:48:00 GMT
References: <[email-masked]>
Organization: Indiana University CSCI, Bloomington
Lines: 59
Nf-ID: #R:cup.portal.com:-1583500:silver:12600047:000:2495
Nf-From: silver.bacs.indiana.edu!commgrp    Mar 21 15:48:00 1989

In article <[email-masked]>, [email-masked] (Jay M Novello)
requests PRO-2004 mods.

[posted mods deleted]

>There is a TURBO-Scan mod where you can up the scan speed to
>around 30ch/s by replacing the resonator crystal in step 6 with a
>10MHz version.

previously posted by <??>:
] Turbo scan for the 2004 ??? Yes !! Someone has realized that if you 
] replace the present 7.37 MHz ceramic resonator CX501, with a 10.7 MHz
] ceramic resonator it really boosts the scan/search speed! The present
] resonator is soldered between pins 29 and 30 of the CPU (IC-503). 
] Rumor has it that a 10.00 MHz computer xtal will work just fine. 
] Note: The effect of the speed mod on weak signal performance is 
] presently unknown.

The resonator is for the CPU clock oscillator.  Jacque KA9FJS confirms 
that the mod works with an ordinary 10 MHz computer crystal ($1 at 
hamfest) but reports a possibly-undesirable side effect:  Increasing 
the clock rate _decreases_ the resume-scan delay time.  Jacque says:  
"The manual says delay is 2 seconds; with mod, delay is <1 second.  
Painful if a channel is filled with slow responders."  He reports no 
detection problems at the increased scan rate.

>Also, by soldering a diode in... position D-510 (if it were labled) 
>you can add 10 channels to each bank for a total of 400 ch.  The 
>problem with this is that then the keypad's labelling for channel 
>banks becomes incorrect...
  
PRO2004 keyboard template for 400-channel modification, showing 
new channel-bank contents:

         +-----------+-----------+-----------+
         |     1     |     2     |     3     |
         |           |           |           |
         |   1 - 40  |  41 - 80  |  81 - 120 |
         +-----------+-----------+-----------+
         |     4     |     5     |     6     |
         |           |           |           |
         | 121 - 160 | 161 - 200 | 201 - 240 |
         +-----------+-----------+-----------+
         |     7     |     8     |     9     |
         |           |           |           |
         | 241 - 280 | 281 - 320 | 321 - 360 |
         +-----------+-----------+-----------+ 
         |     0     |           |           |
         |           |     .     |   CLEAR   |
         | 361 - 400 |           |           |
         +-----------+-----------+-----------+
--

Frank     W9MKV @ K9IU     [email-masked]
{inuxc,rutgers,uunet!uiucdcs,pur-ee}!iuvax!silver!commgrp
"Hams across the water, hams across the sky."