Re: Discriminator Tap points on BC780 Circuit Board

Posted by DaveH on December 28, 2000 at 17:05:46:

In Reply to: Re: Discriminator Tap points on BC780 Circuit Board posted by Greg Knox on December 28, 2000 at 15:18:47:

Greg,

The "slicer" output sounds like an LVTTL-compatible output...makes
sense. But I hope you're not recommending hooking this directly up to
an RS-232 port.

RS-232 has a logic dead-zone from -3v to +3v and anything that manages
to work in this way is pure luck.

Another reason is that with Murphy's law, if this is hand-wired it's
all too easy to accidentally connect an *output* from the other device to
the slicer output from the '780, which with levels anywhere from -15v to
+15v would likely damage the radio.

A TTL to RS-232 convertor chip such as MAX232 would solve this.

Dave

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