Mini Iambic PCB


From: W. Daniel (pandora!daniel@Think.COM)
Date: Thu Jun 23 1994 - 23:29:36 EDT

Hi Gang,

        For those interested, here's the component list for the keyer.

        U1 78L05
        U2 Curtis 8044ABM
        D1,D2 IN4148
        D3,D4 IN4007

        R1 56k, 5% 1/4 watt carbon film
        VR2 Mini preset 470k or 500k
        R3 220
        R4,R7 1M
        R5 10M
        R6,R10 470
        R8 47k
        R9 4.7k
        R11 91k
        VR12 500k potentiometer

        C1,C5 0.22, mini profile multilayer
        C2 not used
        C3 0.1
        C4,C6,C8 0.01
        C7 0.15

        All of this goes onto a 1" x 1.5" board with space for 3 mounting
holes. Should I pre-drill the mounting holes or should I leave it up to you
to drill which holes suit you guys most? Suggestions? There are 2 jumpers
positions on board to select Mode A or Mode B keying but you install only
ONE jumper. Other than that, all on board connections are routed without
jumpers. Its pretty dense but not crammed. Off board connections are:-

        +Vcc 7-18V power supply, on board regulated 5V
        Manual Key optional but for those who want both, like me.
        Dot paddle
        Dash paddle
        VR12 Speed high side
        VR12 Speed low side

        The profile of this board is limited by the vertically mounted 1/4
watt resistors. Hope this gives you a pretty good idea of what you're in
for. I can't say the board quality is the best as I am doing this myself. I
am using a computer to lay out the board so you won't see ugly tracks, and
photo-exposure to get the mask on. This results in very good definition
tracks. However, I cannot tin the tracks or solder mask it. Instead I leave
the photo resist on, which looks like green enamel and protects the board,
and you can solder through the resist or if you like, remove it with alcohol
or some mild solvent. I thought this is a good alternative to solder
masking. Soldering through the resist is easy, no effort at all. The only
thing may be my cutting of the board. The board is fibre-glass material and
VERY difficult to cut, I will file the sides of the board for a smooth finish
and I hope it will look good enough for most of you. Ok, that's it.

        FYI I am in Singapore, that's half-way round the world from most of
you. So I'd like to keep the partial kit as partial as possible. This will
easy my mailing them out. As such I will probably supply only components
which you can't get or are too expensive to get there.

        For those who have inquired, my address is:-

        Daniel Wee
        7 Mount Sophia Road
        Singapore 0922

        BUT do not send anything yet, I will announce when I am ready to
send, then you can send the money, and please, no checks. $US checks are a
nightmare to handle around here.


| Daniel Wee  |             | ** Man needs more
| UUCP1.12b   | |  than a new start, he
| SNEWS 1.91  |!pandora!daniel             |  needs a new heart! **

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