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                          Converting a Wideband Phoenix VHF / UHF Unit for Ham Band Use

With Integral CTCSS Encoding / Decoding

(Click Here for the Legacy External MX-COM 465P Conversion)

Phoenix Picture

New! -  Phoenix Service Manuals (Thanks to Kevin Custer - W3KKC -  of the Repeater Builder's Group for this courtesy):

1. Introduction

    The Phoenix units are easy to convert as an external control head with volume and squelch controls need not be built. The radio comes equipped with a volume control and (with some models) an internal speaker.  Before starting the conversion, it's suggested that you read the instructions through to the end.  You may email me with any questions / suggestions.

The Phoenix radio can be converted for frequency agile operation in one of two ways:

2. Preparatory StepsSchematic

3. Steps Common to Both Conversions - Complete These First

4. Local Conversion

For this conversion method, almost everything is now done.  Only three other connections need to be made:
    The two remaining connections involve the microphone.  Since the external M/P (and not the mike) will be 'keying' the radio, the mike PTT lead is cut and run over a DB-25 lead to the control head.  Another DB-25 lead will be required to connect the PTT circuitry within the control head to the Phoenix.
Note: Do not use too much heat when soldering to the severed chassis connection as the PTT lead might drop down and make accidental contact with the frame of the radio.  To fix this, the board itself will have to be removed.

    Connect the microphone (and a speaker, if needed)  to the radio and move on to the final adjustments.

5. Remote Conversion

The remote conversion involves the removal of the Phoenix' volume control and ON / OFF switch and the installation of a remote power activation relay. These functions will now reside within the control head.
Remove the volume control by cutting these leads above the solder connections. The ground connection which may be severed at the P/C board itself.
6. Preliminary Testing

    Ensure that all connections are correct.  A  test table provides resistance and voltage measurements at each of the DB-25 connector pins.

7. Connecting the Control Head

    You'll have to build up a control head, and the required components are available.  A large Radio Shack plastic enclosure works perfectly as it can house the P/C board, the keypad, LCD, the volume control (with an OFF / ON switch), a mike jack and even a small speaker.  

    A 'connectorized' control head may be used with several radios of the same or different frequency if the pin assignment convention is the same for each.  Since the new M/P uses flash memory, it's easy to change the radio interface.  See suggestions on Control Head construction.

    Note: You may program channels used in any of these radios into their respective 'banks'.  There are 5 banks of 20 channels each.

    With the power off, connect the Control Head to the DB-25 cable.  If you have the time, double check the end to end connections with your meter.  If not, at least verify that the 13 VDC leads are wired properly.

8. Final Adjustments

Note: My Phoenix VHF did not require any CTCSS deviation adjustment.

Connection Table


Phoenix Connection Points

M/P Board

Function / Comments

13.2 VDC COMMON Option  - Low Current Radio / Relay  2 3 None

 Switched DC to M/P

Ground Phoenix J-910 pins 6, 7, 8 - see text MAIN Pin 9


On / Off Remote Option - Low Current Relay Winding  2 17 N/A

Low Power Relay

SPI - Enab U-804 - Pin 13 2 15 PLL - Pin 1 PLL Enable
SPI - Clock U-804 - Pin 9 2 13 PLL - Pin 2 PLL Clock
SPI - Data U - 804 - Pin 5  2 10 PLL - Pin 3 PLL Data
Chan Chg U-804 - Pin 11 2 14 Main Pin 6 PLL  Fast Lock
Transmit Phoenix J-911, pin 2 (see text)  2 1 PLL - Pin 4


COR Detect Phoenix J-910 - Pin 2 - 5 MAIN - Pin 1 -
Mike High Phoenix J-911, pin 4 (see text)   2 9 N/A

Remote Option Only 
Spare for Local Option

Speaker Phoenix J-910 pin 3 - 19 N/A Remote Speaker
Speaker Phoenix  J-910 Pin 7 - 20 N/A Remote Speaker
Volume High Remote Option Only  (see text)
- 25 N/A

Spare for Local Option

Volume Center  Remote Option Only  (see text) - 4 N/A Spare for Local Option
CTCSS OUT Phoenix + C-718 (see text) 2 18 MAIN Pin 2 Transmit CTCSS
CTCSS RCV U-801 (M/P) - Pin 29 - 2 MAIN Pin 3 Receive CTCSS
TMT OVER U-801 (M/P) - Pin 28 (see text) 2 11 JP10 - Pin 2 (Optional)Transmit Override
LOCK (PLL) U-801 (M/P) - Pin 6 (see text) 2 6 JP10 - Pin 1 (Optional) PLL Lock Ind.
PTT - Local Isolated Mike PTT Lead 2 23 MAIN Pin 5 For Local Option Only
Spare for Remote Option
PTT - Return Isolated Phoenix PTT Point 2 24 PLL Pin 4 For Local Option Only
Spare for Remote Option

Test Table - DB-25 Cable Connections - for a Phoenix VHF 

Pin # Function R to Gnd Volts Comments
1 Phoenix PTT 2.9M    PTT Lead used to Key the Phoenix Radio
2 CTCSS RCV 1.6K    CTCSS from the Phoenix to the MX-465 Chip
3 M/P Board Power Inf
4 Volume Center     -
5 COR (CAS) 8.6K    -
6 Lock       PLL Lock Indicator
7 Ground 0 0 Chassis Ground
8 Reserved  - - -
9 Mike High  .6K   -
10 SPI Data  11.9K   Serial PLL Data Connection
11  TMT OVER     Transmit Override (see text)
12 Ground 0 0 Chassis Ground
13 SPI Clock     Serial PLL Clock Connection
14 Channel Change 11.7K    Enables Fast PLL Lock
15 SPI Enable     PLL Enable Connection
16 Ground 0 0 Chassis Ground
17 ON - OFF Switch Inf 13 Activates (Fused) Low Current Relay
18 CTCSS TMT     CTCSS Lead from MX-465 to Radio
19 Speaker 3.3     
20 Speaker 1.7     
21 Ground 0 0 Chassis Ground
22 Ground 0 0 Chassis Ground
23 Reserved -
24 Reserved   - -
25 Vol / Squelch High   0 -
Shield 'Shields' Cable 1.6 Ohm 0

DISCLAIMER - - If you follow the steps outlined herein, you do so at your own risk. I cannot, nor will not, be responsible for any possible damage to radio equipment, personal property, to yourself or to others caused by modifications that you may make to the radio as a result of your reading this.

The M/P controls TRANSMITTING as well as receiving on many frequencies, suitable for a wide range of HF, VHF and UHF needs. In the USA, TRANSMIT operation requires a license issued by the FCC  for the class of operation intended.  Amateur radio licensees must maintain strict control over their equipment, preventing unlicensed operation within the amateur bands, or outside of them.

Copyright 2000 - 2010 - K3JLS