Important Note; Multi-Vehicle Operation; Functional Description - Pyramid SVR-200 LA Service Manual

Generally, vehicular repeaters are used as mobile extenders in cross-band operation: the link is VHF Low Band
simplex and the mobile is Lo-band, VHF, UHF or trunking. In-band operation is possible, but care must be taken
to prevent interference between the mobile's higher power transmitter and the repeater receiver. Proper frequency
selection and antenna placement are important even in cross-band operation, but especially for inband use. The
use of low power pre-selector cavities may be placed in line with the repeater antenna cable since it is simplex and
low power.

Important Note

The SVR-200 operates on simplex frequencies; part of the multi-vehicle format dictates that all of the
SVR-200s must be able to monitor all link traffic on site and be able to determine if a handheld is transmitting, or
if other repeaters are transmitting. The handhelds must transmit CTCSS, but should be carrier squelch receive.
The handhelds should not use CTCSS decode if the repeater is utilizing the multi-vehicle format, as this will
interfere with the priority sampling which is essential for multi-vehicle operation. Also, the handhelds would have
to have different encode and decode tones in order for the repeater to be able to tell the difference between
handhelds and other repeaters, so the handhelds would not be able to hear each other. The repeaters should not
transmit CTCSS unless used only in a single vehicle environment.
When the user leaves the vehicle, they activate the SVR-200 via their mobile radio front panel or a separate
switch. When the mobile radio is receiving carrier and proper tone, the SVR-200 will begin transmitting on the
handheld's receive frequency. The user is able to hear and respond to all radio traffic, including other handhelds
at the site. The SVR-200 can be programmed to give the handhelds priority in a conversation by periodically
sampling for handheld activity (carrier and proper tone) during base-to-portable transmissions. During sampling,
if the SVR-200 detects a handheld transmission, it will cease transmissions, key the mobile radio and repeat
portable-to-base. This allows the handheld to respond during repeater hang time or during full duplex interconnect
calls. Priority sampling can be enabled/disabled through PC programming and the interval can be programmed
between .25 seconds and 2.5 seconds in .25 second increments.
The SVR-200 has a fixed 3 minute time out timer for base-to-portable transmissions. If the mobile COR is
active for more than 3 minutes (and the SVR-200 is the priority unit) it will send a double blip and cease transmission
until the mobile COR is inactive. The 3 minute time-out is in affect regardless of whether the SVR-200 is
programmed for priority sampling or not.

Multi-vehicle operation

When the SVR-200 is first activated, it will transmit a short "lock tone" that alerts the user that the system is
functioning. It will then assume the priority status and be ready to repeat any base-to-portable or portable-to-base
transmissions. If another unit arrives on scene and is activated, it too will transmit the "lock tone"; when the first
SVR-200 detects the lock tone from the second unit, it will increment a "priority counter" and will no longer repeat
any transmissions. The recently arrived unit will be the priority repeater, and the first unit will be 1 count away from
priority. This process will continue for each unit that arrives at the site, creating a priority hierarchy for up to 256
vehicles, each with a unique count and only one unit at priority status. The SVR-200 will not transmit it's lock tone
if the radio channel is busy when first enabled. It will wait in non-priority status until all transmissions cease, then
send its lock tone and become the priority unit.
Even though the other SVR-200s are not at priority status, they will continue to monitor the channel for activity.
If the priority unit were to leave the scene or become disabled, the other units will detect the condition to repeat
and determine that there is no priority unit repeating the transmission. They will then begin to decrement their
priority counters until one of them reaches the priority status and begins repeating the transmission. Since the
SVR-200s are all at different counts, only one will reach priority status and begin transmitting. The other units will
sense the new priority repeater and cease counting down, preserving the priority hierarchy.
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SVR-200 Service Manual

Functional Description