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Motorola R100 JAUX and Interfacing Information Compiled by Robert W. Meister WA1MIK

JAUX is wired to J3 on the QRN4314A interface board. J2 on the interface board is wired to the station control board mounted on the top cover. Pins with no information are Not Connected or Not Used. Almost all of the signals pass through buffer or inverter circuits on the interface board. The Direction is IN TO or OUT OF JAUX. This information is also presented in the R100 Instruction Manual starting on page 48 of the PDF file.

JAUX	J3	Signal Name	Dir	J2	To Controller Board
1	12	Phone Patch Ground	Gnd	16	Ground
2
3	6	Station A+	Out	1	Station A+
4	4	Phone Patch PTT	In	9	Q812-C
5	10	TX Audio	In	12,13,14	U802-13,U800-6,U824-6
6	15	Ground	Gnd	16	Ground
7	9	RX Audio	Out	11	U824-7
8	16	Ground	Gnd	16	Ground
9	1	Phone Patch Alert Inhibit	Out	5,6	U809-11,Q807-C
10	7	Phone Patch Inhibit	Out	7,8	U805-11,S1 (REPEATER DISABLE)
11
12	2	Phone Patch Audio Ctrl	Out	2,3,4	SW3 (LOCAL PTT),U829-6,Q830-C
13
14	13	Desk Set Ground	Gnd	16	Ground
15	18	Desk Set Speaker High	Out	15	P2-2 (SPEAKER HIGH)
16	11	Desk Set Mike High	In	14	U824-6
17	14	Desk Set Mike Gnd	Gnd	16	Ground
18	8	Desk Set Monitor	In	10	S805 (PL DISABLE)
19	3	Desk Set PTT	In	9	Q812-C
20	5	Repeater Knockdown	In	8	S1 (REPEATER DISABLE)
21
22
23
24
25

Interfacing common repeater controllers is easily done through the JAux connector with the exception of having to add a couple of wires to bring out a few additional signals. The CSI controller hookup sheet is VERY helpful here.

For D-Star controllers and such, the following connection points work very well (this information was provided by Scott N3XCC):

• Gnd - Chassis ground at power supply.
• TX Audio - Lift negative end of C607, near the big coil and mounting screw on the TX command board, between the 11-pin connector that goes to the RF board and the DA-15 I/O connector. This feeds audio direct to the modulator, so you will need external pre-emphasis and limiting.
• PTT - Point maked "B" on the TX command board (not marked on schematic but it goes to the DA-15 connector's PTT input). This point is midway between the microprocessor and the 11-pin connector that goes to the RF board, in line with the 11-pin connector. Ground to transmit.
• RX Audio - Buffered Discriminator audio is on U551A pin 4. U551 is between the 11-pin connector that goes to the RF board and the DA-15 I/O connector. Use a DC blocking cap. This is flat and unsquelched.
• CSQ - Active high at Q720's collector on the RX command board. Alternatively, active low at pin 11 of the 11-pin connector that goes to the RF board (Carrier Squelch Detect that feeds Q720). Don't load down either of these pins; use a high impedance input (more than 10k) or buffer it.

Remember to program the receiver for carrier squelch and no PL/DPL transmit tone.

Contact Information:

The author can be contacted at: his-callsign [ at ] comcast [ dot ] net.

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This page originally posted on Wednesday 13-Mar-2013

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This web page, this web site, the information presented in and on its pages and in these modifications and conversions is © Copyrighted 1995 and (date of last update) by Kevin Custer W3KKC and multiple originating authors. All Rights Reserved, including that of paper and web publication elsewhere.