Astro25 is the second generation of the Astro (Motorola's name for Digital Voice) radios.

This includes the following:

Mobiles
- PM1500 - M79 Head only, Conventional Only, VHF/UHF only, High Power only (110w)
- XTL1500 - MX head only, Trunking VHF/UHF/7-800/900 Mid Power Only
- XTL2500 - M5 or O3 Head, VHF/UHF/7-800/900 Mid Power and High Power
- XTL5000 - W3-9, O3 or O5 Heads, VHF/UHF/7-800/900 Mid Power and High Power
Portables
- XTS1500
- XTS2500
- XTS3500
- XTS5000
- XTS4000 - Flip phone arrangement. There are only 5 known examples of this radio and they are resold on eBay ad infinitum.
- MT1500
- SSE5000 - looks like an ASTRO Saber, but is a UHF ASTRO25 radio, made for NYPD and is 450-488 MHz only.

Control heads

Mobiles support the following control heads

W3
W4
W5
W7
W9
M79 - PM1500 only
MX - XTL1500 Only
M5 - XTL2500 Only
O5 - XTL5000 Only
O3 - XTL5000 and XTL2500 with export control head.

The W heads are the SB9600 based heads from the Astro Spectra. These will all work but need a special TIB. Note that the W3 head is the only head that will support controlling 2 radios.

Note the M5 and O5 are the same head, just a small hidden keypad button identifies it. Cutting it and flipping it is an easy way to change between them.

What's not known is if the control head type is something that business logic decided or if it's hard set in the firmware. Example: The default codeplugs you can generate in depot are only certain heads for certain radios, but this is just business logic diving it. It may be possible to change a XTL5000 codeplug to support an M79 or MX head, but it's unknown if the radio or CPS would support this.

TIB / CHIB / CHUC

The Transceiver Interconnect board and Control Head Interconnect Board are the boards that connect to the control head and radio brick in remote mount setups. These are different based on the control heads used. These are also called "remote interconnect board" in the service manual

TIBs - Transceiver Interface Board. Provides connectivity between transceiver and the CAN cable. Also, interface for accessories when TIB is used on a high-power transceiver.

HLN6883A/B - Mid Power Brick - For W4, W5, W7, and W9 control heads
HLN6884A   - Mid Power Brick - For the Motorcycle W4, W5, and W7 control heads
HLN6885A/B - Mid Power Brick - For W3 control head only
HLN6915B   - Mid Power Brick - For W3 control head only (Unsure of the diff between this and HLN6885)
HLN6902C   - Hig Power Brick - For W4, W5, W7, and W9 control heads
HLN6901C   - Hig Power Brick - For W3 control head only
HLN1472    - Hig Power Brick - For M79 Control Head (PM1500)
PMUN1036   - Mid Power Brick - For O3 / O5 (CAN Bus Heads)

CHIB - Control Head Interface Board. Used to provide functionality / connectivity between the CHUC and control head.

HLN6912    - O5 CHIB
PMLN4866A  - M79 CHIB for PM1500

CHUC - Control Head Universal Connector - A separate board which provides connectivity to the CHIB and control head.

TIB differences

HLN6883/84/85

These are the differences of the TIB parts. Refer to the service manual to see what they are, most are chip resistor jumpers.

Designation	HLN6883	HLN6884	HLN6885
C732	-	-	X
C753	-	-	X
C759	-	-	X
C760	-	-	X
C761	-	-	X
C762	-	-	X
C763	-	-	X
C764	-	-	X
C766	-	-	X
C769	-	-	X
C770	-	-	X
C771	-	-	X
C781	-	-	X
C783	-	-	X
C785	-	-	X
C786	-	-	X
C789	-	-	X
C791	-	-	X
C792	-	-	X
C794	-	-	X
C795	-	-	X
C796	-	-	X
C797	-	-	X
C798	-	-	X
CR600	-	-	X
CR601	-	-	X
D602	-	-	X
D603	-	-	X
D605	-	-	X
HD003	X	-	X
HD004	X	-	X
J6	X	-	X
JU12	X	X	-
JU601	X	X	-
JU602	-	-	X
JU603	X	X	-
JU613	X	-	X
JU616	-	-	X
JU618	-	-	X
JU626	-	-	X
JU628	X	-	-
JU629	X	-	-
JU631	X	X	-
JU650	X	-	X
JU651	-	X	-
JU652	-	-	X
JU657	X	X	-
JU676	-	-	X
Q602	-	-	X
Q603	-	-	X
Q604	-	-	X
Q606	-	-	X
R609	-	-	X
R610	-	-	X
R612	-	-	X
R615	-	-	X
R616	-	-	X
R617	-	-	X
R619	-	-	X
R620	-	-	X
R621	-	-	X
R622	-	-	X
R623	-	-	X
R624	-	-	X
R625	-	-	X
R670	-	-	X
R671	-	-	X
R672	-	-	X
R673	-	-	X
R674	-	-	X
R675	-	-	X
R676	-	-	X
R678	-	-	X
U601	-	-	X
U602	-	-	X
U603	-	-	X
VR624	-	-	X
VR625	-	-	X
VR627	-	-	X
VR671	-	-	X
VR672	-	-	X

Crypto

Crypto needs the UCM and Carrier board.

Note that the flash on the UCM stores the crypto keys, in an encrypted format. The UCM stores this UCM key in ram, and it's backed up by the capacitor on the carrier board. If infinity key retention is enabled, then the data is still encrypted, but the UCM encryption key is written to flash as well.

Carrier Board

The XTL Mobile uses a 3 day or 30 second retention carrier board. There are two differnt versions, depending on the control head you use.

HLN6876 - Secure Interface 3-Day retention for SB9600 based heads (W series) 
HLN6877 - Secure Interface 30 second retention for SB9600 based heads (W series)
PHLN6918 - Secure Interface 3-Day retention for CAN Bus based heads (O/M series)
PHLN6919 - Secure Interface 30 second retention for CAN Bus based heads (O/M series)

It is unknown if the 6918/6919 boards are backwards compatible with SB9600 based control heads.