06-08-2018, 08:28 AM
Here's the data sheet for the BAL 0408 series delays. With a few odd notes in my handwriting
Looking at other notes in my files (I have quite a lot of data about video filters and delays by Matthey, BAL and others) I reckoned that up to 200ns you could use them for high quality video without any worries. Beyond that the performance got worse.
They need to be terminated (ideally both ends) in their characteristic impedance. Unless you are deliberately using them for certain kinds of pulse forming. In the sort of video kit that I designed they were used for short video delays and longer pulse delays. longer video delays meant rather expensive equalised delay lines. I've also seen them used as the delay elements in analogue transversal filters. Leaving off the output termination I think gives you symmetric taps.
Not sure what you'd use them for these days. If you need this sort of delay at logic level you'd likely use active delays in a modern design. Though these would work OK provided you drive them directly from logic without an input series termination. The 500R impedance are the most useful for that kind of work as 100R is a fairly hefty load for most logic gates.
Looking at other notes in my files (I have quite a lot of data about video filters and delays by Matthey, BAL and others) I reckoned that up to 200ns you could use them for high quality video without any worries. Beyond that the performance got worse.
They need to be terminated (ideally both ends) in their characteristic impedance. Unless you are deliberately using them for certain kinds of pulse forming. In the sort of video kit that I designed they were used for short video delays and longer pulse delays. longer video delays meant rather expensive equalised delay lines. I've also seen them used as the delay elements in analogue transversal filters. Leaving off the output termination I think gives you symmetric taps.
Not sure what you'd use them for these days. If you need this sort of delay at logic level you'd likely use active delays in a modern design. Though these would work OK provided you drive them directly from logic without an input series termination. The 500R impedance are the most useful for that kind of work as 100R is a fairly hefty load for most logic gates.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
