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Main / Changeovers (video, audio, SDI) / PRAA-4065
| PRAA-4065M(E) series broadcast "smart" audiochangeovers |
The PRAA-4065M/ME broadcast audio changeover protects an analog balanced stereo audio transmission lines with up to 600ms of audio delay skew.
PRAA-4065 switches the main output "1" between the primary input "A" and the secondary input "B" in automatic or manual mode, under local or remote control. The latching relays used in the unit maintain the state during a period of power loss.
PRAA-4065 rear panel
When in automatic changeover mode, PRAA-4065 analyses the following set of parameters:
- a 2~12dB audio level drop on one input relative to the other (the level difference is presettable in 1dB increments). A switchback occurs when the level difference falls below 2dB.
- an audio level drops below a preset "silence threshold" on one input while the other has an above-the-threshold audio level. The "silence threshold" is presettable in 0 to minus 60dB range with 1dB increments.
The forward delay (an interval between a moment a fault was detected on primary input and an actual change over to the secondary input) is user-presettable:
- for video signal faults the delay is 0~99.9sec with 0.1sec increments
- for audio signal faults the delay is 0.5~99.5sec with 0.5sec increments
The recovery delay is user-presettable in 1~999sec range with 1sec increments. An immediate recovery switching to the primary input takes place if a fault occurs on the secondary input.
The monitor output provides an audio signal from an input currently selected as a back-up.
PRAA-4065 can be controlled:
- locally from it's front panel
- remotely from a separate PRR-4065P console
- via Ethernet from a PC (PRAA-4065ME only)
- by GPI commands
Technical specifications
- AUDIO Inputs
| input type, connectors |
balanced, XLR female |
| input impedance |
600 Ohm |
| signal level |
0~6dB |
- AUDIO Outputs
| output type, connectors |
balanced, XLR male |
| number of outputs |
one program, one MONITOR |
| maximum output level |
+21dB |
| load impedance |
600 Ohm |
- AUDIO parameters
| frequency response ripple |
less than 0.1dB from 20Hz to 20kHz |
| THD |
less than 0.05% |
| channel separation |
better than 90dB |
| interchannel audio level skew |
less than 0.2dB |
| interchannel phase skew |
less than 0.5° |
| SNR |
better than 80dB |
Remote control (GPI and RS-485 parameters)
- RS-485: up to 25 meters, RJ-45 connector
- GPI: dry-reed contacts, up to 10W load (100V/0.5A max), DB-25 connector
General data
- Power supply: 220V AC, 50Hz
- Power consumption: 10W
- Dimentions:
- PRAA-4065: 44*482*230mm
- PRR-4065P console: 44*482*40mm
- Weight:
- PRAA-4065: 6kg
- PRR-4065P console: 1.5kg
Controls and indicators
The SELECT button toggles through the list of all the parameters, the < and > buttons edit a currently selected entry.
- AUDIO set of parameters:
- DIF LEVEL: audio level difference, 2dB~12dB with 0.5dB steps or level monitoring OFF
- THR: silence threshold, –30dB to - 60dB or silence monitoring OFF
- TIME: delay time (0,1s to 99,9s) before the changeover on any of the faults being monitored
- RECOVERY: delay time (1s to 999s) before the changeback on any of the conditions under monitoring, OFF disables automatic changeback
Please, note! To avoid an erroneous changeback the "RECOVERY" delay should be longer than the longest changeover delay.
The STATUS indicators display:
- operation mode (A, B or AUTO)
- AUDIO set of parameters (main and standby inputs):
- DIF.LEVEL:
- lit in green: level difference is within the preset limit (2~12dB)
- lit in red: level difference is outside of the preset limit
- not lit: level monitoring is OFF
Please, note! In case of simultaneous silence/underlevel condition on A and B inputs - an unrecoverable fault - both LEDs are lit in red.
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