[TowerTalk] Re: Band decoder for FT-100

[K0FF]

Jim, there are 16 combinations of 4 wire BCD. If the FT-100 band data that
you need falls within the first 10, then use a 7445 BCD decoder/driver. This
will give you a ground on ONE of 10 different output lines with appropriate
BCD input. It ignores the combinations above 10. This is a great chip in
that it will drive a 12V relay direct, up to 80mA.
 If what you need lies in the upper area, then use a 74150 or 74154. They
will give you an output for all 16 codes. Use a 5V relays or 2N2222 driver
transistors on these.

Any of the above will require a +5 power connection, or if not available
from the rig, use 12V through a 7805. A .001 to ground from any wire that
goes into the real world will bypass any RF that might get on them. Good
luck, sounds like a nice project.

Geo>K0FF
-----Original Message-----
From: Jim Aguirre <wb7dhc@nwlink.com>
To: K0FF <K0FF@ARRL.NET>
Date: Wednesday, August 16, 2000 8:34 PM
Subject: Re: Band decoder for FT-100


>Thanks for the response, George.
>
>No, the manual doesn't say ANYTHING about the Band A/B/C/D pinouts.  They
>are designed to activate the Yaesu tuners and amplifier.  The folks at
>Yaesu told me how the matrix works, but didn't provide the truth table.  I
>didn't ask specifically for it since I figured it would be pretty easy to
>measure the outputs and create a table.
>
>The biggest problem right now is that I don't have the radio in my
>hands...it's at Yaesu for warranty repairs.  As soon as I get it back, I
>plan to do what you suggested; create a truth table and then use a BCD
>decoder and driver.  Since time is getting short, I was hoping someone had
>already done the "grunt work."
>
>Thanks,
>
>Jim
>
>At 08:23 PM 8/16/00 -0500, you wrote:
>>Jim, is there a truth table in the manual that would describe the distinct
>>combinations per band? If not can you make one up? Then it would be a
simple
>>matter to decode anything you want using a BCD decoder chip and a driver.
>>Geo>K0FF
>>-----Original Message-----
>>From: Jim Aguirre <wb7dhc@nwlink.com>
>>To: wsvhf@qth.net <wsvhf@qth.net>; vhf@w6yx.stanford.edu
>><vhf@w6yx.stanford.edu>; nwvhf@qth.net <nwvhf@qth.net>
>>Date: Wednesday, August 16, 2000 8:00 PM
>>Subject: Band decoder for FT-100
>>
>>
>>>Does anyone have any ideas for building a band decoder for 28, 50, 144
and
>>>432 MHz using the Band A/B/C/D pinouts on the Yaesu FT-100 data pigtail.
>>>The Band A/B/C/D pinouts switch a matrix of 0 or 5 VDC outputs to
identify
>>>the various bands; e.g. 0-5-5-0 might represent 20M (hypothetical
example).
>>>
>>>I want to be able to switch PTT lines between transverters and amplifiers
>>>connected to this radio.  This has been done for the HF bands (there's
even
>>>a commercial product for that...not built by Yaesu) but nothing is
>>>available that I know of for the VHF/UHF bands.
>>>
>>>Any ideas?
>>>
>>>Jim - W7DHC
>>>
>>>
>>>
>>>------
>>>Submissions:                    vhf@w6yx.stanford.edu
>>>Subscription/removal requests:  vhf-request@w6yx.stanford.edu
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>>
>>
>>
>


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