Station Video Mux: Difference between revisions

Station Video Mux (view source)

Revision as of 09:06, 24 May 2007

98 bytes removed , 24 May 2007

Controller PIC been replaced

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Revision as of 20:01, 23 May 2007 (view source) Sprow (talk \| contribs) (Mux(es) detail) ← Older edit		Revision as of 09:06, 24 May 2007 (view source) Dummy User (talk \| contribs) (Controller PIC been replaced) Newer edit →
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	The outputs originally drove 8 copies of each bus to avoid the need for seperate distribution amplifiers, however in a heavily loaded system some crosstalk was observed. This was misdiagnosed as due to electric fields (!) and the integrated amplifiers chopped out, despite the MAX497 buffers being socketted. It is believed simply increasing the decoupling to the power supply would have resolved the problem and left the unit at its full specification.		The outputs originally drove 8 copies of each bus to avoid the need for seperate distribution amplifiers, however in a heavily loaded system some crosstalk was observed. This was misdiagnosed as due to electric fields (!) and the integrated amplifiers chopped out, despite the MAX497 buffers being socketted. It is believed simply increasing the decoupling to the power supply would have resolved the problem and left the unit at its full specification.

	In ~~2007 it still runs as~~ the ~~main studio video routing crosspoint, but not as~~ the ~~network mux~~. ~~When~~ [[~~BBC Schedula~~]] ~~talked directly to it it performed both tasks~~, ~~it used a simple two wire protocol which proved too difficult to emulate despite~~ the ~~protocol being documented in~~ the ~~service manual, which has presumably since been mislaid~~.		In 2006 the original PIC within the controller was replaced with a PIC18F2455. This was the first step towards giving [[Spider and SchedSeven]] control of the Mux, although currently the USB side of the firmware is still under development.