2.3.1Internal Configuration Jumpers
The following internal configuration adjustments may be made by removing or replacing jumpers on the PCB. The jumper positions are designed to accept a 0 Ω resistor of 0603 size. Refer to Appendix C for component location.
This service should only be performed by a qualified technician. Garmin is not responsible for damage caused during adjustment of these internal configuration jumper settings. Refer to the GMA 240 Maintenance Manual for disassembly/reassembly instructions.
The GMA 240 contains static sensitive components. Observe proper
Component | Name | Default | Description | |
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R0303 | Alert Mutes | Populated | If this jumper is removed, music will not be | |
| Music |
| interrupted by alert audio. Default operation | |
|
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| is recommended. | |
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| |
R0304 | COM1 Internal | Empty | If a jumper is supplied in these positions, | |
| Sidetone |
| internal sidetone will be heard during PTT to | |
|
|
| simulate received sidetone from a radio that | |
R0305 | COM2 Internal | Empty | ||
does not provide one during transmission. | ||||
| Sidetone |
| ||
|
| This should only be used if a radio does not | ||
|
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| ||
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| perform this function already. | |
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| |
R0308 | TEL Internal | Populated | If this jumper is removed, intercom audio | |
| Sidetone |
| and intercom sidetone will not be heard | |
|
|
| when the TEL button is selected. Many | |
|
|
| phones supply sidetone when a call is in | |
|
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| session. This causes a noticeable change in | |
|
|
| intercom sound quality but it is usually not | |
|
|
| disruptive. Default operation is | |
|
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| recommended unless the effect of sidetone | |
|
|
| from the telephone is disruptive to intercom | |
|
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| operation. | |
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| |
R0315 | TEL jack detect | Empty | If a jumper is supplied in this position, when | |
| bypass |
| TEL is selected the audio panel will assume | |
|
|
| a telephone is in use in the front jack | |
|
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| regardless of phone detection. This should | |
|
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| be used only if the audio panel is not | |
|
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| capable of properly detecting the telephone | |
|
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| that will be used in the installation. | |
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Page | GMA 240 Installation Manual |
Rev. A |