Howdy...I am interested in building a cheap and easy band decoder for
an icom 706mkIIg that will ultimately be used for switching relays on a
remote antenna switch. I have searched around and found a few people
that make them and offer kits, but would like to see if anyone has
built one with good results. Any help or ideas would greatly be
appreciated...

Thanks,

Dave

Dave wrote:
Howdy...I am interested in building a cheap and easy band decoder for
an icom 706mkIIg that will ultimately be used for switching relays on a
remote antenna switch. I have searched around and found a few people
that make them and offer kits, but would like to see if anyone has
built one with good results. Any help or ideas would greatly be
appreciated...

Too bad it's not an IC-745 which has an analog voltage output
proportional to the pre-WARC ham bands.

I designed such a device about ten years ago. It works on any
100 watt transmitter. It had a divide by 1024 pre-scalar to
bring the signals down to a comfortable speed for CMOS logic.
Then a window would open for ~4mS and a 2048 max counter would
record the counts. Those bits were stored and used as address
bits on an EPROM whose output indicated the band. I used it to
automatically switch in variable lengths of ladder-line depending
upon the band.

I wonder how many people would be interested in me digging
up that old design which is buried in a box in my garage?
--
73, Cecil http://www.qsl.net/w5dxp

Cecil Moore wrote:
Dave wrote:

Howdy...I am interested in building a cheap and easy band decoder for
an icom 706mkIIg that will ultimately be used for switching relays on a
remote antenna switch. I have searched around and found a few people
that make them and offer kits, but would like to see if anyone has
built one with good results. Any help or ideas would greatly be
appreciated...


Too bad it's not an IC-745 which has an analog voltage output
proportional to the pre-WARC ham bands.


The 706 (on pin 5 of the 13 pin accessory socket) still has the Icom
analog voltage output based on the selected band BUT unfortunately it is
not a unique decoding. From some notes of mine it looks like:
160m = 7.0-8.0V
80-75m = 6.0-6.8V
40m = 5.0-5.8V
30m = 0V
20m = 4.0-4.8V
17m-15m = 3.0-3.8V
12m-10m = 2.0-2.8V
6m-2m = 1.0-1.9V
When I realized that 17m and 15m decode the same and 12m and 10m decode
the same I dropped the project. However this may not concern you. The
best way is to decode the CIV bus and read the frequency on the bus but
this is more complicated.

73,
Larry, W0QE

"Dave" wrote in message
oups.com...
Howdy...I am interested in building a cheap and easy band decoder for
an icom 706mkIIg that will ultimately be used for switching relays on a
remote antenna switch. I have searched around and found a few people
that make them and offer kits, but would like to see if anyone has
built one with good results. Any help or ideas would greatly be
appreciated...

Thanks,

Dave

Elecraft also has a kit -- look at the KRC2 kit .... should offer everything
you want ... Elecraft mail reflector has many happy builders.
http://www.elecraft.com/KRC2/krc2.htm

w9gb

Thanks for the info guys. I wasn't aware that Elecraft made a decoder
too. That type of decoder is a possibility too. I'm not reall sure
which way I want to go with the decoder yet- use the analog voltages or
the CI-V bus...??? So we see what else I can find and try to make up
my mind. I guess ON4AOI ( http://www.on4aoi.be/ ) makes a decent kit
for decoding too.

Thanks again,

Dave
KB8NNU

I knew I had this, but couldn't find it when I read the post then when I
found it, I couldn't remember where I saw the question.

I found it, I found it:

Icoms have the same voltage that Cecil refers to and here is a "decoder". I
believe it identifies all pre-WARC _and_ WARC bands except 12 meters (the
rationale being that antenna tuners typically can tune 10 & 12 with the same
components).

http://www.k6xx.com/radio/icbsciv.html

73, Steve, K;9.D,C.I


"gb" wrote in message
...
"Dave" wrote in message
oups.com...
Howdy...I am interested in building a cheap and easy band decoder for
an icom 706mkIIg that will ultimately be used for switching relays on a
remote antenna switch. I have searched around and found a few people
that make them and offer kits, but would like to see if anyone has
built one with good results. Any help or ideas would greatly be
appreciated...

Thanks,

Dave

Elecraft also has a kit -- look at the KRC2 kit .... should offer
everything
you want ... Elecraft mail reflector has many happy builders.
http://www.elecraft.com/KRC2/krc2.htm

w9gb