[GreenKeys] RS232 to TTY Loop Boards

[Lester Veenstra]

I am thinking of a rework of the board to include the original DB9 interface
and the option of a USB to TTL/RS232 converter daughter board.
Also would probably like to use a chassis mount power resistor for the loop
setting value to allow better heat dissipation, for example:

RH0102K000FE02

http://www.vishay.com/docs/30201/30201.pdf

Would like to really find a nice cache of about 3k wire wound variable, 10w
or larger reostats.
Other jumper configurable options of external loop supply, bypass meter,
echo kbd loop to printer loop, etc
Also consider add a diode bridge to receive opto isolator to remove loop
polarity issues.

Lester B Veenstra  MØYCM K1YCM W8YCM
lester at veenstras.com

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-----Original Message-----
From: GreenKeys [mailto:greenkeys-bounces at mailman.qth.net] On Behalf Of
Jeffrey D Angus
Sent: Monday, February 16, 2015 11:33 AM
To: greenkeys at mailman.qth.net
Subject: Re: [GreenKeys] RS232 to TTY Loop Boards

Perhaps I wasn't quite clear on this.
I'm NOT making the boards.
I _am_ offering to assemble them if you don't want to make them yourself.
Labor to assemble them is roughly $10 each + shipping.

However, that being said, If I get enough orders for boards, I can have 
them
made via ExpressPCB. They are, not cheap. For example, a 1.9" x 2.2" board,
double sided with solder mask and silk screen is roughly $300 for twenty of
them. So $15 apiece.
Without the silk screen and solder mask, the cost drops down to $153 or
about $7.65 each.
The "set up cost per order" is the real cost here. $245 for the full 
board, and
$61 for the one without the solder mask and silk screening.

Obviously, if you all go crazy and order enough of them, it brings the total
distributed costs down. For example, 40 of the simple boards drops down to
$5.85 apiece instead of $7.65.

Then, there's also the cost of the parts for the boards. Mouser does give a
price break on quantity. So that helps.

However, both the PS7141E and the thick film 10 watt resistor are non-
stocked items. The cost of them are about $3 each.

If y'all want me to, I will sit down, do a PC board layout for currently
available parts, and an itemized parts list with costs for all three items.
Parts, PC board and Labor. My guess at this point is going to be around
$30 per board assembled. Closer to $40 if you want the pretty boards
with solder mask and silk screen.



-- 
Jeff-1.0
wa6fwi
http://www.foxsmercantile.com

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