4. Connections
Warning - High Voltage! Remove Power Before Servicing!
High voltage may be present on this card (if used for switching phone lines with super- imposed dc current signaling) which could cause serious injury or loss of life. Only qualified personnel familiar with this type of circuitry should work on this equipment. To prevent injury, damaging the card or other equipment, remove power before making connections.
4.1 Power connections
Connect positive 12 Vdc to pins 55 and 56. Connect the 12 Vdc return (normally ground) to pins 39 and 40. For best performance, use at least 20 AWG or larger wire for power connec- tions.
4.2Signal Connections and Card Edge Con- nector Pin Assignment
Refer to the schematic and Table 4 (shows the 1505’s pin assignments and has a blank for any customized functions that might be configured) for the appropriate pin number to make connec- tions. Use at least 24 AWG wire for signal connections.
4.3 Special considerations for optional wiring
4.3.1 Receive Compressor/Limiter Jumpers
Each receive channel has a compressor/limiter circuit which helps provide a consistent audio level. If some external equipment already in- cludes compressor/limiters, these circuits may be bypassed by changing the associated jumper’s position. For example, moving JP6 from the “A” (in) to the “B” position (out) by- passes Rx Ch #1’s Compressor/Limiter. Refer to Table 1 and the schematic for the appropri- ate jumper selection.
JP# | Function |
| Jumper Status |
| Notes | |
|
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| In | Out | A | B |
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1 | Mic PTT/Speaker Mute | Coupled | Separate | N/A | N/A | PTT mutes Speaker |
2 | Mic, Carbon Element | In | - | N/A | N/A |
|
3 | Mic, Electret Element | In | - | N/A | N/A |
|
N/A | Mic, Dynamic, High Out | - | - | N/A | N/A | JP2, 3, 4 out |
4 | Mic, Dynamic, Low Out | In | - | N/A | N/A |
|
5 | Mic, Comp./Lim. | N/A | N/A | In | Bypass |
|
6 | Rx Ch #1 Comp./Lim. | N/A | N/A | In | Bypass |
|
7 | Rx Ch #2 Comp./Lim. | N/A | N/A | In | Bypass |
|
8 | Rx Ch #4 Comp./Lim. | N/A | N/A | In | Bypass |
|
9 | Rx Ch #3 Comp./Lim. | N/A | N/A | In | Bypass |
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10 | RX Ch #3 600Ω/10ΚΩ | 600Ω | 10ΚΩ | Ν/Α | Ν/Α |
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11 | RX Ch #1 600Ω/10ΚΩ | 600Ω | 10ΚΩ | Ν/Α | Ν/Α |
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12 | RX Ch #4 600Ω/10ΚΩ | 600Ω | 10ΚΩ | Ν/Α | Ν/Α |
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13 | RX Ch #2 600Ω/10ΚΩ | 600Ω | 10ΚΩ | Ν/Α | Ν/Α |
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Table 1. Jumper Options
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