JPS builds on its industry leading SNV-12™ analog receiver voter, allowing a customer’s IP network to transport receiver and transmitter audio between the SNV-12 voter chassis and remote RX/TX sites. This is made possible by our QMT-1B™ remote units and SVM-3 three-channel IP backhaul Site Voter Modules.
Network delays and jitter create challenges to traditional analog voting which requires time-synchronized signals from multiple voting receivers. These challenges are capably handled by the combination of the QMT-1B and the SVM-3, in conjunction with updated software in the CPM-3 Control Processor Module.
JPS QMT-1B
Description
IP BACKHAUL REMOTE for the SNV-12
Quality, Measurement & Transport
When an unsquelch condition occurs, signaling that receiver audio should be sent to the voter, the QMT-1B measures signal quality and converts the analog audio to IP for transfer to the SVM-3. Each SVM-3 module can service three receivers, and works in conjunction with the CPM-3 to monitor the arrival timing of incoming audio. This allows the voted signals to be resynchronized for accurate voting and switching between sites during a voting sequence.
At the SNV-12 voter, the remote received audio, whether interfaced by analog means to an SVM-2 or by an IP network to an SVM-3, is buffered by the site voter modules until the CPM-3 determines that all unsquelched sites have reported in. The CPM-3 then coordinates re-alignment of the various signals.
QMT-1B Single Channel or Multicircuit Rack Mount Versions
SVM-3 IP backhaul currently implements exclusively lowest noise (FM) voting, however delay time RX unsquelch to TX is typically below 400ms (approximately 350ms + network delay). One reason for the SVM-3’s success is the highly capable QMT-1B.
The QMT-1B is largely configurable using its browser-based user interface. RX Audio Input and TX Audio Output levels are adjustable via soft pots. COR input is polarity active low or high, selectable. EIA Keytones or PTT can be used for TX audio output. The operating temperature is from -20 to +60 ℃, and it can be stored at temperatures between -40 to +85 ℃.
The QMT-R™ is a rack mount version of the QMT-1B that can contain from one to four QMT-1Bs. The rack mount configuration fits naturally into many settings where SNV-12 Voters are already installed. Due to its larger size, a larger power supply (48VDC) and a fuse have been added. Otherwise, each installed QMT-1B in the QMT-R operates exactly like a QMT-1B.
