[hpsdr] OZY Startup Info

[Philip Covington]

Chris, Phil:

See in line below:

On 7/17/06, Christopher T. Day <CTDay at lbl.gov> wrote:
> Phil_C,
>
> Phil_H and I got very confused about this on the TeamSpeak Friday. By
> following the traces and buzzing it out, we both concluded that the mark
> on the silk-screen labeled the anode connection.

The "a" marks on the silkscreen denote the ANODE.  I have a note to
myself to increase the size of the silkscreen because it seems it is
not clear that they are "a" and not some other character.

> Phil_H checked his
> diodes with a DVM and for his LEDs concluded that the green marks were
> on the anode. However, I checked the LIT-ON datasheet for these devices
> and concluded that the green dots should be marking the cathode of the
> LEDs. See the data sheet here:
> http://rocky.digikey.com/WebLib/Lite-on/Web%20Data/LTST-C171CKT.pdf

Phil is using LTST-C170CKT parts - not the thin LTST-C171CKT parts.
The thin C171 parts were not in stock at Digikey at the time I placed
the order.  John Koster asked me to order a reel quantity of the LEDs
since he was ordering parts for the Atlas Kits. The parts list for the
OZY lists the C170 parts:
<http://sales.digikey.com/scripts/ru.dll?action=pb_view&pb_glue=1011790>

> and a photo here:
> http://rocky.digikey.com/WebLib/Lite-on/Web%20Photos/LTST-C171AKT,LTST-C
> 171CKT,LTST-C171EKT,LTST-C171GKT,LTST-C171YKT.jpg
>
> I put my diodes down with the green dots to the right; D13 lights when I
> apply power (the FPGA was not down at that point). Phil_H put his down
> with the green dots to the left and his light as well.
>
> On your pictures, you have the green dots to the left. I presume they
> light.

Yep they do... and all go in the same direction including D13 which I
do not have installed on my board yet (since I know the 3.3VD supply
is there).

> On my Atlas, I have the green dots _away_ from the 'A' on the
> silk-screen and they all light. (They are green light versions of the
> same part as Ozy.)
>
> Does any one have any idea what is going on?

Yes, you are using a different part than Phil, Bill, Lyle, Steve, and me. :-)

>         Chris - AE6VK

To summarize:

The CK170 part has the ANODE marked.

The CK171 part has the CATHODE marked.

Don't ask me why LITEON cannot be consistent in their marking...or why
other manufacturers cannot use some standard...  I always do what Phil
H did - use a DMM to check polarity before soldering to be sure.

73 de Phil N8VB

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