[ICOM] Warning about W1GEE interface cables

[Floyd Sense]

Sure - I have 5 serial ports - all active with other devices and the cable
fails with all of them.  In fact, this particular cable also fails with the
wrap test provided by the manufacturer.  I don't know if the 9 pin version
of the cable that I have uses the MAX-232 as the 25 pin version did.
Perhaps so, but the housing is very small indeed and not sure there's room
for that module.

I'm going to try a low voltage MOV across the transceiver's "remote" jack to
try and prevent future problems.  The transistor replacements are cheap, but
a pain in the rear to install.

K8AC

----- Original Message ----- 
From: "Gary Fiber" <g.fiber at verizon.net>
To: "ICOM Reflector" <icom at mailman.qth.net>
Sent: Tuesday, June 01, 2004 11:09 PM
Subject: Re: [ICOM] Warning about W1GEE interface cables


> Floyd,
>
> Good on the 765 being not involved in the lightning strike. Any way to
> check the computer's serial port?
>
> All the level's I remember off the top of my head is 0 and + 5 volts DC. I
> am sure there might be a tighter spec for the logic chip. Even though the
> CPU is likely cmos the CI-V buss is still based on TTL levels. Internal to
> the transceiver as you know a couple of transistors are used to interface
> to the CPU. Fortunately they are also the weak link most times when you
> experience an event like you did.
>
> The CT-17 using the MAX-232 chip always worked fine, so you could base
> loosely the level investigation on that and go from there I suspect. One
> here posted the MAX-232 does not go to a full 0 volts, thats likely, seems
> to remember from about 1975 classes the spec for a TTL low was not 0 volts
> but something less than 1/2 volt. Geeze should remember that level but
will
> have to consult a logic data book these days I don't use that information
> much so its buried in the grey matter. :)
>
> Hope some of this helps.
>
> Gary K8IZ
>
>
> I just ordered an Icom cable from K1NU who says he knows his cables work
> >properly with the 781 and 765.  Which gets back to the main point of my
> >original post: W1GEE is selling interface cables WHICH HE KNOWS WILL NOT
> >WORK with the 781 even though his literature says otherwise.  When I get
> >caught up on the other repair work here, maybe I'll dig into it and see
why
> >it doesn't work.  I don't recall seeing anything in the 781 service
manual
> >about the CIV signal level required to drive the 781 properly - perhaps
you
> >know the answer to that?
> >
> >K8AC
>
> Gary Fiber K8IZ
> GROL PG-19-6691
> Washington State Resident
>
>
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