T2000-A80 Line Interface Fitting Instructions

Introduction

The T2000-A80 line interface kit enables connection of the T2000 receiver and transmitter audio circuitry to a two-wire transmission line. The line interface PCB is mounted inside the T2000 Series II radio and is application configurable using PCB links.

Parts Required

The T2000-A80 kit contains the following items:

• 1 T2000-A80 line interface PCB assembly
• 1 15-way high-density D-range plug and shroud
• 1 1µF capacitor (*C64)
• 1 47nF capacitor (*C60)
• 28 0Ω chip resistors (for PCB links)
• 3 M3x8 pan Pozi Taptite screws
• 2 micromatch connectors (S13 & S14 on the logic PCB)
• 1 female screw lock kit (in plastic bag)
• 2 4-40x5/16 pan Pozi Taptite screws (black)

Fitting

Refer to Figure 1.

1. Remove the top cover of the radio by unscrewing the four bottom cover screws, unscrew the logic PCB and fold out.
2. Unclip the D-range blanking plate in the rear of the T2000 chassis.
3. Position the T2000-A80 PCB as shown, and connect the Micromatch connectors P13 and P14 to S13 and S14 on the T2000 logic PCB.
4. For T2010 & T2015 models: Remove R513 (0Ω resistor) on the top side of the logic PCB.
5. Connect a wire from S24 (TX REG) on the T2000-A80 PCB to TP609 on the logic PCB, as shown in Figure 1.
6. Select the T2000-A80 PCB link options, using the 0Ω resistors provided. Refer to "T2000-A80 Link Options" for a description of the PCB links.
7. Adjust RV1, RV2 and RV3 on the T2000-A80 PCB, as described in "T2000-A80 Set-Up".
8. Carefully fold the logic and T2000-A80 PCBs back into position, guiding the T2000-A80 D-range socket (S21) through the hole provided in the T2000 chassis.
9. Secure the PCBs using the three logic PCB retaining screws and the three M3x8 screws provided, and refit the top cover.
10. Fit the female screw lock kit to S21, and plug the D-range assembly provided in the kit into the T2000-A80 D-range socket.

Note: Holes are provided in the T2000 Series II chassis for the D-range screw locks. Use the two black 4-40 Taptite screws provided to form threads for the screw locks, and discard the screw lock kit nuts.

T2000-A80 Link Options

The following table explains the T2000-A80 PCB link options. Standard links for T2010 and T2020 models are shown as shaded.

T2000-A80 Link Options

Link	A	B	C	D	E	F	No Link	Option
LINK1	TX LINE IN	TX SIG IN	LINE OUT MUTE	LINE IN MUTE	flat	line output: audio response
LINK2	2 pole	6 pole	line output: filter response
LINK3	600Ω	150Ω	line output: impedance
LINK4	600Ω	150Ω	line output: impedance
LINK5	0dB	15dB	line output: attenuation
LINK6	15dB	0dB	line output: attenuation
LINK7	0dB	15dB	line output: attenuation
LINK8	15dB	0dB	line output: attenuation
LINK9	linked	separated	line input: line output
LINK10	600Ω	150Ω	line input: impedance
LINK11	0dB	15dB	line input: attenuation
LINK12	flat pre-emphasis	pre-emphasis	line input: audio response
LINK13	pre-emphasis	flat	line input: audio response
LINK14	flat	pre-emphasis	line input: audio response
LINK15	bidirectional	unidirectional keying input/output
LINK16	line PTT	none	PTT input
LINK17	standard	permanent microphone mute
LINK18	standard	trunked Rx gate sense
LINK19	on aux	opto driver sense
LINK20	standard	disabled line circuit enable
LINK21	key 0V	key 5V	PTT input
LINK22	busy 5V	busy 0V	Rx-gate 0V	Rx-gate 5V	Rx gate/busy output
LINK23	enabled	disabled	time delay circuit
LINK24	Tx 5V/Rx 0V	Tx 0V/Rx 5V	disabled	Tx/Rx output
LINK25	enabled	disabled	Not clear to send (trunked only)
LINK26	locked 5V	locked 0V	in-lock output
LINK27	2 pole	6 pole	line output filter
LINK28	2 pole	6 pole	RX OUT

Component Changes

Component	Value	Function
*C60	47nF	Rx gate delay
*C64	1µF (provided in the kit)	Gives a short transmit release delay
*C120	4n7	Line matching
R77	4k7Ω	Remove for modem operation (trunked radios), or to remove 'external inhibit on busy' (conventional radios)
R90, R91	10Ω	Remove for 2-wire crossband when moulded cord sets are used (HD 15M-HD 15M). This is to avoid power supply conflicts between radios (+8V out, +13V out).

Refer to Figure 2 (components found on the top side of the PCB are shown with a 'dashed' outline). Certain applications may require component changes. The following table describes these components, and their locations.

Diagram of T2000-A80 PCB Links and I/O pads

T2000-A80 Set-Up

• If the logic and T2000-A80 PCBs are unscrewed and folded out for adjustment, a wire must be temporarily fitted from the radio chassis to the options chassis ground pad (S35), as shown in Figure 1.
• This section assumes that the T2000 radio has been correctly aligned for normal operation. Refer to the M2000-00 Series II Service Manual (issue 300, or later), Section 8.14, for application details.
• Check that the auxiliary LED, ?, is on (function LED, F on trunked radios).
• Signals for balanced transmissions are generally less than 0dBm, and are typically between -10dBm and -20dBm.
• In the following instructions, deviation settings are given first for wide band radios, followed by settings for narrow band radios in brackets [].
• Set up the test equipment as shown in Figure 3.

Servicing

Refer to the M2000-00 Series II Service Manual (issue 300, or later), Section 8.14. For additional information on external channel control of T201X radios, refer to Section 5.9.