[1000mp] RTTY and the FT1000MP

[Joe Subich, W4TV]

Ted,

The FT-1000 family of radios (D/MP/Mark V/Field) have a diode in
series with most of the PTT lines on the back panel.  They take an
exceptionally "had" pull to ground to accommodate the drop in the
diode.

The best thing to do is to add a 2N2222 or similar to the output
of the Opto-isolator (emitter to ground, base to the output of the
Opto, collector to the FT-1000).  That increases the current gain
and will often fix the problem.

The other solution is to use an opto with a high gain darlington
output.

73,

    ... Joe, W4TV


> -----Original Message-----
> From: 1000mp-bounces at mailman.qth.net
> [mailto:1000mp-bounces at mailman.qth.net] On Behalf Of Ted Boerkamp
> Sent: Saturday, March 18, 2006 2:52 PM
> To: 1000mp Reflector
> Subject: [1000mp] RTTY and the FT1000MP
>
>
> Hello Everyone,
> 			Just wondered if anyone has experienced the same
> frustration as myself in trying to get a soundblaster interface for
> rtty working....specifically the PTT circuit.
> I have used the opto-coupler circuits shown on a few websites for
> this purpose and I am tying into the RTTY jack on the back of the
> 1000MP (original model). When I click on TX in MMTTY, a LED lights
> on the input side of the opto IC, but the 1000MP is not keyed.
> So I know that the signal is getting to the opto-coupler but the
> output doesn't seem to be right to key up the radio.
> I have tried two different versions of opto ICs, one even having a
> darlington output to no avail. Can someone confirm for me that the
> simple resistor/transistor(2n2222) circuit shown on a number of
> websites, will work for this radio??? or does someone have a better
> idea for the PTT circuit?? Any help is greatly appreciated.
> I was hoping to get my feet wet in rtty this weekend in the contest,
> but I guess it will have to wait.
> Thanks and 73
>
> Ted Boerkamp VE3SS
>
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