[Amps] OT: RF Speech Processor Kits - Final Final

[G3rzp at aol.com]

The Plessey SL 1626 was originally intended for the CB AM market. It didn't have enough low pass filtering for the land mobile FM market, which had quite tight specs on the pre-emphasis and low pass filtering. For some reason, it was not very popular, although a couple of South African manufacturers used it.

The SL6270 was another beast: basically, a combination of the SL620 AGC generator and SL630 AF amplifier in function, it didn't use the 'hang' AGC of the earlier devices. It could, under some circumstances, overload with the overshoot. But t was a nice device, and amde a good Wien Bridge AF oscillator, too, although I never wrote that up as an Application Note.

Before you ask, I was the applications guy for all those analogue Plessey radio parts, from joining in 1979 until the early 90's, and being the only engineer left who has experience of those parts, still get the occasional queries to answer today.

73

Peter G3RZP