[Elecraft] KEYOUT PTT only when transverter band selected

[ww2r2]

Having made requests of Elecraft at the end of last year for a "eot only
when transverting" from the k3 with no success, I developed the "eot only
when xverting" circuit as part of my auto switching transverter interface
written up at http://g4fre.com/k3vhf.pdf. It will also appear in the
proceedings of the Central States VHF Society Conference happening next
weekend

Dave

WW2R
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Message: 8
Date: Sun, 12 Jul 2009 10:18:42 -0700 (PDT)
From: "Julian, G4ILO" <julian.g4ilo at gmail.com>
Subject: [Elecraft]  KEYOUT PTT only when transverter band selected
To: elecraft at mailman.qth.net
Message-ID: <1247419122732-3246434.post at n2.nabble.com>
Content-Type: text/plain; charset=us-ascii


I don't have a linear amplifier. I do have a transverter, and I use the KEY
OUT jack to put it into TX. Trouble is, it puts the transverter into TX
whatever band I'm using. For LO stability reasons (not to mention that I can
never remember to switch the transverter off when I'm not using it) I'd
prefer to be able to leave the transverter switched on but only receive a
PTT signal when the VHF band is selected. I think that means I'd need a
circuit that combines the state of DIGOUT0 with KEYOUT-LP, such that it
grounds the transverter PTT input when DIGOUT0 is 0V and KEYOUT-LP is
grounded. Has anyone made something like that?