04-11-2018, 01:13 PM
(This post was last modified: 04-11-2018, 01:14 PM by ppppenguin.)
Peter, Frank told me about the missing "e" when I helped with his forthcoming Bulletin article. All will be reveealed then, unless Frank wants to say something here.
Trevor, at the price of R-Pi, if they can't do intercarrier sound then just use 2, one for audio, one for video. There are 2 modulator chips in the Aurora and Hedghog simply because one couldn't quite manage AM sound at 3.5MHz spacing.
It might be possible to do intercarrier sound with System A but it's difficult with any +ve modulation system. Minimum vision carrier must not fall below a certain amount, otherwise sound will be clipped. Since the sound is 6 or 7dB down wrt vision this would mean doing both of:
1: Placing sync tip at something close to 50% carrier. It should work but might fool some sets
2: Reducing the sound carrier level, which would reduce the need to raise sync tip. Again this would work but might annoy some sets.
Yes, you could do iintecarrier System A after a fashion but it would be horrible. It may well be the case that the R-Pi methods can't generate 2 separate RF carriers from a signle computer so that menas using 2 of them.
Trevor, at the price of R-Pi, if they can't do intercarrier sound then just use 2, one for audio, one for video. There are 2 modulator chips in the Aurora and Hedghog simply because one couldn't quite manage AM sound at 3.5MHz spacing.
It might be possible to do intercarrier sound with System A but it's difficult with any +ve modulation system. Minimum vision carrier must not fall below a certain amount, otherwise sound will be clipped. Since the sound is 6 or 7dB down wrt vision this would mean doing both of:
1: Placing sync tip at something close to 50% carrier. It should work but might fool some sets
2: Reducing the sound carrier level, which would reduce the need to raise sync tip. Again this would work but might annoy some sets.
Yes, you could do iintecarrier System A after a fashion but it would be horrible. It may well be the case that the R-Pi methods can't generate 2 separate RF carriers from a signle computer so that menas using 2 of them.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
