[ICOM] Computer Control Interface

Wed Dec 28 13:24:08 EST 2005

SENT TO THE WRONG THREAD

I got it done.

I modified the BUXCOMM RASCAL and it is now keying the CW
JACK on the back of the IC-756PRO as though it was
originally designed to.

I added a *very* simple little circuit to the box which is
comprised of a general purpose NPN a 1K ohm resistor and
that was all it took. Now it takes the keying relay to
ground.

I opened the jacket of the cable going to the serial port
just enough to find the DTR line and connect it to my
little circuit.

After doing so I then ran a line from pin 5 ground and the
collector (center pin) of the CW KEYING JACK and it is
working flawlessly.

All other functions work perfectly also. The buxcomm box
still looks like brand new and all there is now is a new
cable running to the CW KEYING JACK from the same bundle
as the others.

Now I am on to build a CAT circuit for the computer
control aspects of the rig.

I ordered a MAX233 chip from MAXIM/DALLAS fro the CAT
design and have a design I gleaned from the Ham Radio
Deluxe PDF that tells it all about how to kit it and put
it together.

Should have it all going by the end of the week thanks to
you guys and helping guide my thinking.

Now I am armed and dangerous, Hi Hi

Thanks to one and all for your time and help on this
project. I now understand a lot more about how this
process it taking place.

  73 fer nw,
Bob AD5VJ

10X# 37210, FP#-1141, SMIRK#-5177
http://www.n5iet.com/
Code may be taking a back seat for now,
but the pioneering spirit that put the code
there in the first place is out front of it all.

> -----Original Message-----
> From: icom-bounces at mailman.qth.net 
> [mailto:icom-bounces at mailman.qth.net] On Behalf Of Gary
Fiber
> Sent: Wednesday, December 28, 2005 10:12 AM
> To: ICOM Reflector
> Subject: RE: [ICOM] Computer Control Interface
> 
> 
> Well when I was working at Icom the easiest way to
provide a hard 
> ground was to use a transistor externally, no mods
required to the 
> equipment controlling the rig. We could not suggest to
the customer 
> how to modify his after market equipment to make it work
with 
> Icom products.
> 
> I looked at a HM-14 schematic, when you place a hard
ground the U/D 
> connection rig tunes up in frequency, when you ground
through a 470 
> OHM resistor the rig tunes down. I was remembering the
troubles I 
> went through with a customer and his DSP-2232 and using
the Opto 
> isolator to drive a transistor was easiest at the time.
Some programs 
> would control the frequency up / down mode in the
DSP-2232. Others 
> would use an external antenna, radio frequency
controller.
> 
> When I saw the schematic of the MFJ-1289 I assumed Bob
might be 
> experiencing the same issue since the manual reads use
the CW out for 
> FSK keying. I did not get into it to far though.
> I am using a Rig Blaster No Mic and just picked up a
Tigertronics 
> Signalink SL-1+ for my IC-718.
> 
> Buxcomm has a huge site I was hoping to find the product
Bob was 
> using and have a look at the schematic to find any
differences in the 
> FSK Keying as that unit seems to work for him.
> 
> >If you are using an opto to do CW keying via the
UP/DOWN function,
> >then you should be aware that the UP/DOWN sensing in
the Icom is 
> >done by voltage.  That is, it senses the voltage on the
UP/DOWN 
> >line.   The UP/DOWN line is also used for the 4
voice/CW memory 
> >keying but in that case, it senses 4 voltages
> 
> What Icom rig uses the U/D line for Voice and CW memory
keying? Must 
> be the newer models as the older one didn't so far as I
remember.
> 
> Gary K8IZ
> 
> >.  What this means is, if you are using a transistor to
key that
> >line, whether it is the output of an opto or discrete
transistor, 
> >you have to account for the Vcesat of the transistor in
presenting 
> >the line with a voltage.  The UP/DOWN buttons have no
voltage across 
> >them when they are on.  The Vce sat could be several
tenths of a 
> >volt.  If you do the calculations, understanding the
internal series 
> >resistance that is in the radio and the unloaded
voltage, you can 
> >come up with 4 new values of resistance for the keyer
and probably a 
> >new value for the UP/DOWN.  I have done that for the
keyer with 
> >great success.  The only catch with the UP/DOWN, is
that it only 
> >uses one resistance, with the other state grounding the
line.  This 
> >may present a problem if the voltage detection is
looking for 
> >something less that the saturation voltage of the
transistor.  I 
> >have not done an UP/DOWN keyer, so I can't say whether
it will work 
> >or not, but I have done computer controlled interfaces
using the 
> >memory keyer with optos/transistors.
> >
> >
> >At 12/27/2005 12:42 PM, you wrote:
> > >Bob,
> > >
> > >I was looking at the MFJ-1279 schematic and the CW
out is using a
> > Opto Isolator. In the past I remember an Opto isolator
not being
> > able to place a hard enough ground on the Icom UP /
Down input.
> > >The AEA DSP-2232 users had to install a transistor to
provide hard
> > enough ground so the DSP-2232 would cause a frequency
change,
> > mostly to the IC-970. This was done for Doppler shift 
> frequency tracking.
> > >I looked at the Buxcomm site but he has some much
stuff it would
> > take a week to find the product you are using listed.
> > >
> > >Gary K8IZ
> > >
> > >At 07:58 AM 12/27/2005, you wrote:
> > >>Ok I give up on this little project, it is quickly
> > >>becoming not worth my time.
> > >>
> > >>Is someone using an interface with an Icom PRO or II
or
> > >>III that does all the soundcard modes and FSK modes
along with 
> > >>keying CW from A SINGLE COMM PORT that actually
works?
> > >>
> > >>I would like to know what your using so I can look
into 
> getting one.
> > >>
> > >>What is recommended by you guys with the experience?
> > >>
> > >>
> > >>
> > >>  73 fer nw,
> > >>Bob AD5VJ
> > >
> > >----
> > >Your Moderator: Dick Flanagan K7VC, 
> icom-owner at mailman.qth.net Icom 
> > >Users Net: Sundays, 1700Z, 14.316 MHz Icom FAQ: 
> > >http://www.qsl.net/icom/
> >
> >----
> >Your Moderator: Dick Flanagan K7VC,
icom-owner at mailman.qth.net Icom 
> >Users Net: Sundays, 1700Z, 14.316 MHz Icom FAQ: 
> >http://www.qsl.net/icom/
> 
> Gary Fiber K8IZ
> GROL PG-19-6691
> Washington State Resident
> 
> 
> ----
> Your Moderator: Dick Flanagan K7VC, 
> icom-owner at mailman.qth.net Icom Users Net: Sundays,
1700Z, 
> 14.316 MHz Icom FAQ: http://www.qsl.net/icom/
> 