08-11-2016, 03:21 PM
There were various byways in the choice of TV systems. Our 405 and France's 819 were ultimately dead ends, though successful in their own way. Brian Pethers, who worked for the GPO, then BBC, then Michael Cox Electronics, proposed a SECAM-like system that was one of several discussed by Carnt and Townsend in Volume 2 of "Colour Television". See pp221-240.
System N was a nasty kludge for Argentina who had the unfortunate combination of 625/50 TV with 6MHz US style channels. It was only ever used for transmission, all production was done with standard PAL equipment. I was at Michael Cox Electronics when we won a contract to supply Argentina with PAL-B/G to PAL-N transcoders.
Strictly speaking PAL-B/G refers to RF transmission standards. In the studio it's simply PAL, with 4.43MHz subcarrier. The only other PAL variant that was used on air was PAL-M in Brazil. This was a properly engineered 525/60 version of PAL. Since it was a small market, all production was done in NTSC with transcoding to PAL-M for transmission.
Both these transcoding processes were fairly simple since field and line rates were the same for input and output. Incidentally SECAM was a horrendous system for production. You can only fade or mix it by partially dismantling it, a lossy process. I remember that Cox made native SECAM vision mixers which were both complex and horrible. It's no surprise that much French and Eastern European material was made in PAL, then transcoded to SECAM. It's also not surprising that France led the way in analogue component video for production. Meant that all routers, mixers and suchlike had 3x complexity but once Betacam component recorders were availabe it just worked brilliantly and gave a smooth upgrade path to digital production.
System N was a nasty kludge for Argentina who had the unfortunate combination of 625/50 TV with 6MHz US style channels. It was only ever used for transmission, all production was done with standard PAL equipment. I was at Michael Cox Electronics when we won a contract to supply Argentina with PAL-B/G to PAL-N transcoders.
Strictly speaking PAL-B/G refers to RF transmission standards. In the studio it's simply PAL, with 4.43MHz subcarrier. The only other PAL variant that was used on air was PAL-M in Brazil. This was a properly engineered 525/60 version of PAL. Since it was a small market, all production was done in NTSC with transcoding to PAL-M for transmission.
Both these transcoding processes were fairly simple since field and line rates were the same for input and output. Incidentally SECAM was a horrendous system for production. You can only fade or mix it by partially dismantling it, a lossy process. I remember that Cox made native SECAM vision mixers which were both complex and horrible. It's no surprise that much French and Eastern European material was made in PAL, then transcoded to SECAM. It's also not surprising that France led the way in analogue component video for production. Meant that all routers, mixers and suchlike had 3x complexity but once Betacam component recorders were availabe it just worked brilliantly and gave a smooth upgrade path to digital production.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
