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Model SVR-214
Multi-Channel Synthesized
Vehicular Repeater
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Features:
- Up to 14 Channels Tx & Rx
- Motorola Pac/RT Compatible
- "First Man Out' with priority sampling
- Synthesized operation PC programmable frequencies and tones
- LTR , EDACS and Motorola trunking compatible
Benefits:
- Public Safety - Wide area coverage without expensive satellite receivers
- Paramedics - Maintain communications even inside of buildings
- Utilities - Crossband repeat works with existing low-band systems
- 220/800/900 MHz trunking - Mobile coverage with low cost handheld
- Fleets - Eliminate pagers, cell phones and missed calls
Need technical specifications? Click to for information.
Introduction
The Pyramid Communications model SVR-214 is a uP controlled, synthesized low power vehicular repeater. It is designed to interface between a high power mobile radio and a low power handheld. If the radio operator is out of the vehicle and the mobile radio is receiving a transmission, the SVR-214 will repeat the signal to the users handheld. The user may also transmit back to the SVR-214 via their handheld, and the transmission will be repeated back to the base by the high power mobile radio, effectively extending the range of the low power handheld. On-board logic, controlled by the microprocessor, ensures that only one vehicle will become active as the repeater, should several vehicles arrive at the same scene. The logic also handles cases where the priority vehicle leaves the scene (or fails), or another priority vehicle arrives from another scene.
- Completely automatic operation
When the user leaves the vehicle, they activate the SVR-214 via their mobile radio front panel or a separate switch. When the mobile radio is receiving carrier and proper tone, the SVR-214 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-214 will cease transmission periodically to check for handheld activity. If the SVR-214 detects proper carrier and tone from a handheld, it will key the mobile radio and repeat the user's transmission. In this way, the handheld is given priority and may respond during repeater hang time.
When the SVR-214 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 handheld or handheld to base transmissions. If another unit arrives at the same site and is activated, it too will transmit the "lock tone"; when the first SVR-214 detects the lock tone from the second unit, it will increment it’s priority counter and will no longer repeat any transmissions. This process will continue for each unit that arrives at the scene, creating a priority hierarchy for up to 256 vehicles.
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 decrementing their priority counters until one of them reaches the priority status and begins repeating the transmission.
If another unit was to arrive from a different scene and it is still the active priority, there will be two active repeaters on the air when a condition to repeat exists. When one of the SVR-214s unkeys to check for handheld activity, it will detect the presence of the other active SVR-214 and increment its priority counter and cease transmission.
If the user were to key the mobile radio locally (and their SVR-214 is the priority unit), the SVR-214 will detect the local mic PTT and repeat the transmission to the other handhelds at the site preserving the system priority hierarchy.
When the model SVR-214 is connected to a trunking radio and the user wishes to access the system from the handheld, they key their handheld briefly then release. The SVR-214 will key the mobile radio for 200mS, during which time it monitors the mobile's transmitter for on-air condition. If it does not see the radio transmit at all (system is busy), it will retry every 5 seconds until successful or time out (30 Sec). It will also send a "busy" tone to the handheld every 5 seconds to indicate the progress of the call attempt. If unsuccessful after 30 seconds, the SVR-214 will transmit an error tone to alert the user that the call attempt failed.
When the SVR-214 detects that the mobile is transmitting, it will continue to monitor the on-air line until the transmitter remains keyed for at least 250 mS to ensure that the radio is not merely handshaking or retrying. After successful acquisition of a voice channel, it will continue to hold the mobile PTT active for 2 seconds and transmit a go-ahead blip to the handheld user. The user then keys their handheld to speak on the voice channel. If the user does not key up within the 2-second period, the SVR-214 will unkey the mobile and send the error tone as before.
The model SVR-214 requires only 6 wires for most installations (7 for trunking) with optional connections for remote enable/disable, and local mic repeat. The model SVR-214 has extensive audio processing and logic control for simplified interfacing to a wide variety of mobile radios and a self test mode for alignment and level settings. All of the operating parameters for frequencies, tones, input polarities and audio responses are PC programmable and easily modified using the FY-1 programming cable.
By installing the RCS-200 remote channel option in the mobile radio, the handheld operator is able to remotely change the mobile channel via a DTMF keypad. The RCS-200 contains a microprocessor controlled voice synthesizer and will acknowledge the channel change request by announcing the selected channel over the link in a female voice. This provides positive acknowledgment as well as notifying other users on the link that the mobile channel has changed. The RCS-200 is compatible with most mobile radios; contact the factory for specific applications and options.
Pyramid Communications has application notes for installation into todays most popular radios from Motorola, EF Johnson. GE Ericsson, Midland, Kenwood, Icom, Relm, Standard and Uniden.
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