Logo GE Phoenix SX EEPROM Conversion

Phoenix SX

Project Description

This project replaces the hard to get EEPROM X22C12 in the GE Phoenix SX radios with a standard 27c128 eprom. Just about any eprom can be used, but I had a pile of 27128's from the 1980's! The eprom hex image is generated by my C program included below or by a windows program called "PSX200 - GE Phoenix Radio Programmer" by Robert E Starr Jr KG4LNE. Only the first 256 bytes of the eprom are used by the radio. In the simple version of this project, the extra address lines on the eprom are grounded. If you need more channels than the radio supports, you can add a dip switch or thumbwheel to add more banks of channels. The 27128 has enough space in it to support 512 channels when the eprom is used in a 16 channel Phoenix SX radio.

bottom view

Eprom and Adapter Installed in the radio

DB9 view

Top View of the Handwired Adapter

Bottom view

Bottom View of the Adapter

offset adapter

Offset adapter -- supported by programming pins around U805 socket

offset adapter

Offset adapter by Ted VE7TFM

System Requirements

A windows XP computer running the PSX200 program to generate the eprom image. An eprom burner that supports your particular eprom version. A GE Phoenix SX radio (does not require the obsolete X22C12 eeprom). You can also generate an eprom image using my C language program available in the "Source Code" section below if you prefer to use linux over windows and want to enjoy the benefits of open source software.

Electrical Drawing(s)

Drawing File - phoenix-sch.png(28K)

Source Code

C Language Prom Image Generator - pgm-sx.c(11K) Version 26 Jan,2004 
This is an intel hex file dump of a test image I
used in a 2 channel Phoenix SX.
The settings are:

Ch A Rx = 150.000 141.3hz tone, Tx 151,000 100hz tone
Ch B Rx = 140.000 141.3hz tone, Tx 141.000 141.3hz tone
CCT timer 1 minute, 5khz ch spacing, and a 13.2Mhz reference

 :100000000F080F0F0F0F000000080F0F0F0F000059
 :1000100000090C02080305010000070E0800050195
 :10002000000A000308090501000A01020800050191
 :1000300008000B0E080B0B0008000C0D0802050150
 :1000400000080F0F0F0F000000080F0F0F0F000028
 :1000500000080F0F0F0F000000080F0F0F0F000018
 :1000600000080F0F0F0F000000080F0F0F0F000008
 :1000700000080F0F0F0F000000080F0F0F0F0000F8
 :100080000F080F0F0F0F000000080F0F0F0F0000D9
 :1000900000080F0F0F0F000000080F0F0F0F0000D8
 :1000A00000080F0F0F0F000000080F0F0F0F0000C8
 :1000B00000080F0F0F0F000000080F0F0F0F0000B8
 :1000C00000080F0F0F0F000000080F0F0F0F0000A8
 :1000D00000080F0F0F0F000000080F0F0F0F000098
 :1000E00000080F0F0F0F000000080F0F0F0F000088
 :1000F00000080F0F0F0F000007080F0F0F0F000071
 :00000001FF
Notes on UHF Phoenix code changes - phoenix-uhf-changes.txt(3.5K)

Resources

Phoenix Microphone Connector (P911)
The 8 circuit terminal housing:  0.156 for J911 is Digi-Key P/N WM-2106-ND
Pins for housings are Digi-Key P/N WM2300-ND

P911  Description
1   GROUND (A-)
2   PTT - TX  (Active LOW)
3   MIC SHIELD GROUND
4   MICROPHONE INPUT HI
5   MICROPHONE INPUT HI
6   RESET (Active LOW)
7   CHANNEL SELECT
8   (I converted this pin to +12V for mic power)



Phoenix Power Connector (P910)
The 11 circuit terminal housing: 0.156 for J910 is Digi-Key P/N WM-2109-ND
Pins for housings are Digi-Key P/N WM2300-ND

P910  Description
1   TO IGNITION SWITCH + (2A Fused)
2   RX MUTE (Active LOW)
3   EXTERNAL SPEAKER HI
4   FILTERED VOL/SQ HI
5   SPARE (Channel A/B Select)
6   GROUND
7   EXTERNAL SPEAKER LOW
8   GROUND
9   CG DISABLE (Active LOW)
10   INTERNAL SPEAKER HI
11   +13.5 VDC POWER INPUT (15A Fused)

Phoenix Programming Instructions LBI31266B(1.8M)
27128 Eprom Data Sheet(180k)
X22C12 EEprom Data Sheet(56k)
Service Section 136-174Mhz Phoenix-SX LBI31213E(1.8M)
136-174Mhz Synthesizer/Interconnect Board LBI31230F(2.0M)
40W 136-174Mhz RX/TXBoard LBI31588B(1.2M)
Frequency Calcs Summary(1.8k)

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