Raytheon SNV-12, Инструкция по установке и эксплуатации

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SNV-12 Operations Manual
3-66
When there is not a sufficient increase in noise between the squelched and unsquelched
receiver audio to operate as described above (usually due to a noisy line), the SVM can instead
indicate an unsquelched condition when it detects actual speech in the receiver audio. Set the
thresholds so that the UNSQ LED lights whenever there is speech in the received signal, but
it‟s out when no speech is present.
For best performance the threshold should always be set to the lowest value that does not cause
false unsquelched indication.
Table 3-57 COR Threshold Selection
SW2-5 SW2-6 Audio Level COR Threshold
OFF OFF Highest Threshold (lowest sensitivity)
ON OFF Medium-High
OFF ON Medium-Low
ON ON Lowest Threshold (highest sensitivity) *
NOTE: Audio Level COR should never be used in conjunction with
Repeat Mode. When Repeat Mode is selected, every time a site is voted,
the associated transmitter is keyed and retransmits the voted audio.
When Audio Level COR is selected, any type of noise burst or
momentary static on the receive audio lines to the voter will cause the
associated SVM to unsquelch and voting will occur. This will create an
unwanted transmission when in Repeat Mode. Since the threshold for
detection of COR is the low level of broadband noise present when the
receiver unsquelches, low-level noise or static will cause the voter to
unsquelch and vote. This is not normally objectionable in non-Repeat
Mode. However, the inadvertent keying of the transmitter that can result
if Repeat Mode is used with this COR type usually requires that pilot
tone generators be added.