27-02-2016, 10:17 PM
Fruitful day at Museum. The new audio/video router system came together fairly easily and works very nicely.
The new control panel is above the DVD player and waveform monitor. The actual routers are the 1U units with cream coloured panels towards the bottom of the right hand rack.
The next thing to be done is to acquire an MP3 player and load it with testcard music. This will be left running in a continuous loop feeding all 3 testcard channels.
Another minor addition would be a peak white generator. This is useful when doing RF level measurements as it guarantees full carrier on the +ve modulated System A. Without a substantial amount of peak white the RF level measurements can be tricky and unreliable. I think I have a few ZNA234 and ZNA134 SPG chips somewhere. Just need to add mixed sync and mixed blanking in the right proportions to get a peak white picture. No need for any refinements, just a resistive mixer to get 300mV of sync and 700mV of video into 75R. I also have SAA1043 SPG chips which would do the job. To be built on pinboard in a diecast box with a BNC at one end and socket for a wallwart at the other.
The Museum is chucking out a lot of stuff at the moment to gain much needed space. I came home with boxes of electrical fittings and a few vintage speakers. They'll all be on the Bring and Buy at Harpenden next Sunday.
The new control panel is above the DVD player and waveform monitor. The actual routers are the 1U units with cream coloured panels towards the bottom of the right hand rack.
The next thing to be done is to acquire an MP3 player and load it with testcard music. This will be left running in a continuous loop feeding all 3 testcard channels.
Another minor addition would be a peak white generator. This is useful when doing RF level measurements as it guarantees full carrier on the +ve modulated System A. Without a substantial amount of peak white the RF level measurements can be tricky and unreliable. I think I have a few ZNA234 and ZNA134 SPG chips somewhere. Just need to add mixed sync and mixed blanking in the right proportions to get a peak white picture. No need for any refinements, just a resistive mixer to get 300mV of sync and 700mV of video into 75R. I also have SAA1043 SPG chips which would do the job. To be built on pinboard in a diecast box with a BNC at one end and socket for a wallwart at the other.
The Museum is chucking out a lot of stuff at the moment to gain much needed space. I came home with boxes of electrical fittings and a few vintage speakers. They'll all be on the Bring and Buy at Harpenden next Sunday.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
