Difference between revisions of "U-229"
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==Pin D Mike== | ==Pin D Mike== | ||
| − | + | Microphone input to the radio. | |
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==Pin E Not Standardized== | ==Pin E Not Standardized== | ||
Revision as of 14:45, 12 April 2012
Contents
Pin A Common Ground
Pin A is used as the common ground for audio and is typically the same as chassis ground.
Pin B Handset speaker
Audio output to the handset speaker.
Pin C Push To Talk
When grounded it puts the transmitter into transmit mode
Pin D Mike
Microphone input to the radio.
Pin E Not Standardized
For classical audio applications pin E is not standardized. Different radios use it for different purposes. For example: PRC-68 Family of Squad Radios uses pin E for "12 Volt" vehicle power input.
The HF manpack radios PRC-74 and PRC-104 use pin E for the CW key input, and it's also used for high speed CW like from a GRA-71. Note that the pin C PTT line can NOT be used for CW keying on a radio that supports SSB operation, since there would be no output.
The VRC-12 series Squad radios uses pin E as the loudspeaker line to drive the LS-454.
The PRC-25, PRC-77 AUDIO and the RT-246, RT-524 & R-442 RETRANS use pin E as the retrans PTT to key the other RT with the Mk-456 Retransmission Kit.
Pin F Not Standardized
This is the center pin that is not present on a true U-229 connector. Many radios install the 6 pin version of this connector, yet do not connect a wire to pin F. Maybe it's done to allow a future modification, or maybe just to standardize the connector? Some equipment does use this pin where the other pins are used in the above audio functions, for example: The PRC-68 Family, except the PRC-68 and PRC-68A, use this pin for digital up and down loading of the channel frequency assignments and as the retransmission PTT output. This supports a retransmission cable and cloning cable that are different than the Mk-456.
