Ah yes, The JEM squelch. If I look around I can probably find the GIF you sent me that became the comparator section for the SuperSquelch Mk.1.
It was pretty good, but there is always room for improvement. By replacing the comparator section with a microcontroller the board can be talored for peoples tastes. I am hoping to write different versions of the firmware to emulate the Micor and MASTR-II with cap mod as well as the continuously variable hang time version. On 4/17/07, Joe Montierth <[EMAIL PROTECTED]> wrote: > A few years ago I designed a dual level squelch circuit that could be a > replacement for the Micor type carrier squelch. I built a couple of the > prototypes and put them into service, and they worked very well, you > really couldn't tell them from the real thing. > > They were designed around readily available and cheap parts, so > replicating it would be very easy. I think total parts costs would be > around $5, not counting the board. > > If anyone is interested, I can supply a PDF of the schematic, or upload > it to the site. > > Somewhere, I have some of the boards, but I don't remember exactly > where they went. > > The schematic I have could probably be simplified even more, it was > just an idea that I came up with, and it worked, so I didn't fool > around with it anymore. > > Joe > > --- skipp025 <[EMAIL PROTECTED]> wrote: > > > Re: mc-3357 & mc-3359 squelch circuit > > > > Many receivers used the two mentioned chips... in both commericial, > > Amateur Radio and classic scanner circuits. I've seen both part > > numbers converted to "tk" numbers in Yaesu and Uniden Radios. > > > > There are a number of working squelch circuits using the back end > > section of the chip with and without external op amps. While the > > Hamtronics circuit is/was rather basic it did work pretty well and > > was easy to experiment with changes/mods. > > > > A faster pussycat version of the same circuit can be found in the > > Spectrum, some (if I remember right) older Maggiore or Melco > > and Icom Repeater Receiver circuits. External op amp sections were > > added as gain buffers and high speed switches to enhance the internal > > > > circuit operation. > > > > The Hamtronics transistor hysterisis circuit works ok so don't > > discount it as a bad design. The receiver is/was a very basic > > circuit and could be used in modest low power repeater operation > > without a lot of grief. > > > > If you really were interested in more work with the mentioned > > chips I can and would be happy to email you some circuit diagrams > > and manuals related to the chips used in quality well engineered > > designs/circuits (in pdf file format). > > > > As in our poor mans repeater project... sometimes when money is > > tight you try to use whatever you can get you hands on. > > > > cheers, > > skipp > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > > > > > > Yahoo! Groups Links > > > >
