> No schematic handy here. It was the stock squelch circuit in a mid-80's > vintage Hamtronics R144 or whatever "repeater grade" RX they were selling > at the time. The noise filter was a simple 2-pole BPF with a very high > Q. The op amp they used was the dedicated op amp within the MC3357 or > MC3359 IF amp/detector-on-a-chip. Nothing wrong with the op amp, just the > circuit design around it.
Roger. http://www.hamtronics.com/pdf/Manuals/R144-older.pdf may be what you were working with. A transistor for hysterieses just rases a number of suspicions. I learned to stop trusting built into IF chip squelch systems when I worked on a Regency repeater many moons ago. > Any decent SPICE simulator should be able to give you the transient > response of your filter. Multisim 6 is far from decent. It crashes more then it run. Subsequent versions are not any better. The entire Electronic workbench series is suspect.
