Ramsey Electronics PPM3 manual

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the far-end phone. So the solution is to use a high amount of compression in order to amplify the far-end, weaker signal much more than the local stronger signal. In this way both sides of the conversation are closer to each other in signal strength when applied to the main mixer. A 100K ohm resistor was used to set the compression level around 7:1. The same chart that was used for the mic circuit can also be used with the phone circuit if a different com- pression ratio is desired.

The clip detect circuit that powers the clip LED is basically constantly com- paring the signals from both the left and right channels against a set threshold that is close to the mixer amp’s upper voltage rail, which is where it clips. There is a little amount of hysteresis to enable the LED to be lit up long enough to visibly see it during short signal spikes. The core of the peak detect circuit is D3, D7, R25, and C24. Basically, an averaging DC peak voltage sample is created, held with a charge on C24, and discharged with R25. R20 and R17 control the charge time of C24.

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Contents Phone Patch Mixer KIT Ramsey Receiver Kits KIT Assembly PPM3 Introduction PPM3 Circuit Description Page Page Kit building tips Ramsey LEARN-AS-YOU-BUILD Assembly StrategyPage Page PPM3 Parts Placement Diagram Capacitors Parts Supplied with Your PPM3 KITMiscellaneous Components PPM3 Schematic Diagram PPM3 Phone Patch Mixer Assembly Page Page Page Page Congratulations Testing Your PPM3 Using the PPM3 Still Having TROUBLE? Troubleshooting GuidePage Conclusion PPM3 Phone Patch Mixer SpecificationsPPM3 Ramsey Kit Warranty Additional Suggested Items Estimated Assembly TimePPM3 Remote Interface KIT Required Tools
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