> -----Original Message-----
> From: Steve Woodruff [mailto:sjwoodr@yahoo.com]
> Sent: Friday, November 08, 2002 9:26 PM
> To: Gil Baron; writelog@contesting.com
> Subject: RE: [WriteLog] ptt line resistance?
>
>
> Ok, i'm attempting to attach a JPG of my
> circuit. Hopefully the reflector doesn't
> strip out attachments automatically. :)
>
> Its actually a NPN 2n2222 transistor that
> i'm using. See attached diagram.
Sorry, meant npn. The circuit looks fine to me. I do not understand why it
would not work. If the CW keying works then so should the PTT. Do you get a
good + voltage at the input when you key? If so, maybe you have a bad
xsistor but this is the circuit I use minus the diodes and the voltage
divider resistor which really are not needed although it does give you
safety , especially the diodes. The only thing is they cost a much as a
blown transistor which has never happened here. You have the right circuit
though and should work.
I got the jpg although it would be stripped from the least it comes ok in
the private email..
>
> You mentioned to use a PNP if "positive
> keying" ... not sure if that is my case or
> not. Rig is ic706mk2g. digging out the
> manual now...
>
> tnx
>
> /steve n9oh
>
> --- Gil Baron <gbaron@charter.net> wrote:
> >
> >
> > > -----Original Message-----
> > > From: writelog-admin@contesting.com
> > > [mailto:writelog-admin@contesting.com]On Behalf Of
> > Steve Woodruff
> > > Sent: Friday, November 08, 2002 8:57 PM
> > > To: writelog@contesting.com
> > > Subject: [WriteLog] ptt line resistance?
> > >
> > >
> > > I now have all mode ptt via cw line RTS.
> > > However... its not working. When i play
> > > SSB messages it is not triggering the
> > > rig's PTT line. I am connecting to the
> > > same port that my footswitch normally
> > > connects to... simple mono plug.
> > >
> > > When i hit a F-# button to play a message,
> > > i can see with a multimeter the resistance
> > > on my PTT line drop down to about 4-6 ohms.
> > > Not much.... but is that enough to keep the
> > > rig from triggering PTT?? If so, how can
> > > i drop the resistance?
> >
> > Be sure the diode is not in the wrong direction. You
> > did not give enough
> > information to really understand your circuit.
> > Perhaps a text based drawing
> > would help. I use no diodes, just a 4.7 k or so to
> > the base and the radio
> > directly connected to the collector with no
> > resistance.
> >
> > Be certain the Transistor is a PNP if Positive
> > keying.
> >
> > Be certain the correct polarity is used from the
> > RTS.
> >
> >
> > If your resistance to ground with an Ohmmeter at the
> > Collector of the
> > transistor is as low as 5 ohms I do not see why the
> > rig does not key? Try
> > just a plain resistor to see what it needs on the
> > rig. I bet over 100 ohms
> > would still key it.
> >
> >
> >
> > >
> > > my ptt circuit uses RTS from the cw serial
> > > port, goes through a 4k7 resistors, then
> > > in parallel with a diode and another 4k7
> > > before hitting a 2n2222.... and then a
> > > final diode before having a PTT + and a
> > > ground line.
> > >
> > > Any ideas? tnx
> > >
> > > Steve, n9oh
> > >
> > >
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> >
> >
>
>
>
> =====
> ----------------------------------------------------------
> Steve Woodruff, N9OH @ 42.18N 88.34W, sjwoodr@yahoo.com
>
> __________________________________________________
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