[arm-allstar] I think I found a new BF-888s board, need help finding COS

[Andrew Hull KE8HEV]

Outstanding, Doug. Thanks!

I took the board off the sink, and easily found the chip. I couldn't find
continuity from pin 1 to any points on the other side of the board, so I
tied in right on the chip.

Once the dab of silicone firms up it'll be time to reassemble.

Thanks again!

Andy
--
Andy Hull
KE8HEV

[Any errors in spelling, fact, or tact are transmission errors]


On Sat, Aug 11, 2018 at 12:57 PM "Doug Crompton via arm-allstar" <
arm-allstar at hamvoip.org> wrote:

> Andy,
>
>   There have been many iterations of the 888 but in all cases they retain
> the 8 pin chip where COS is picked up. I am attaching a photo from the
> howtos at hamvoip.org showing the chip. There are two 8 pin chips and
> part numbers are often hard to find. One of them is the spot - pin 1.
> Placement of the chips changes so you will need to check which one it is.
> The COS goes high on signal - 0V no signal, >2.5V signal.  If you cannot
> find a connection on the circuit side you will have to remove the board to
> get to the chip. Info on doing that is in the howto.
>
>
> *73 Doug*
>
> *WA3DSP*
>
> *http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*
>
>
> On Sat, Aug 11, 2018 at 12:38 PM, "Andrew Hull KE8HEV via arm-allstar" <
> arm-allstar at hamvoip.org> wrote:
>
>> Hello All,
>> I'm in the process of building a simplex node (RA-40 & BF-888s).
>>
>> The BF-888s that I received has a date stamp on the board of 2017-11-04. I
>> believe that this is an updated revision from the board that Chris Hood
>> documents here:
>> http://www.chrishoodblog.com/allstar-node-with-bf-888s-short-board/
>>
>> The design looks similar enough that the RX Audio, PTT, and Mic Audio
>> appear to be in the same places. However, I'm at a loss for COS.
>>
>> Has anyone already solved the mystery for this revision? My Google
>> attempts
>> have turned up nothing.
>>
>> If not, could anyone offer some advice on how to find it myself? I
>> consider
>> myself in the "knows enough to be dangerous" category of low level
>> electronics. So, with a friendly shove in the right direction, I hope I
>> can
>> find it.
>>
>> Here's a photo of my board. I haven't taken it off the heatsink to get a
>> look at the other side.
>> https://photos.app.goo.gl/pcnRfK2X7Pt8HhXKA
>>
>> Thank you!!
>>
>> 73,
>> Andy
>>
>> --
>> Andy Hull
>> KE8HEV
>>
>> [Any errors in spelling, fact, or tact are transmission errors]
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>>
>
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