[sdiy] Re: ASM VCO prototype problem?

[Jaco Sloof]

Hello mr. Ison,

To explain, please look at the ASCII-Matic below.
     ________
1 --[  |__|  ]-- 8
    [        ]
2 --[   CA   ]-- 7
    [        ]
3 --[  3140  ]-- 6
    [        ]
4 --[________]-- 5

1=Offset Null    (Not connected on asm-1 VCO)
2=InV. Input     (Goes to C2 and Source of FET 2n3819 or equiv.)
3=Non Inv. Input (Goes to Ground)
4=V-             (Goes to -15V)
5=Offset Null    (Not connected on asm-1 VCO)
6=Output         (Goes to R17(back) R18(front) R21(Back) and TL082 pin 5)
7=V+             (Goes to +15V)
8=Strobe         (Not connected on asm-1 VCO)

I truly understand your confusion, mr. Ison! Indeed, the schematic is a bit
vague..
If you look closely at the BMP of the Component-side of The VCO, near the
CA3140, you will see that
the "ghost"-connection between the V+ (coming from the IC) and ground (coming
from wirebridge)
is cut UNDER resistor R17.. This is not very clear, looking from the
solder-side of the board.

Actually, looking at my own VCO module, I see that I even soldered the
wirebridge in, and soldered
the other half of the wire bridge (supposedly going to ground) to ground, but
because this wirevridge
does not connect anywhere, it can be omitted completely.

Thank you mr. Ison for pointing out this flaw is in my design, I will see if I
have time this week to
correct the layout and put up a better BMP-Picture of the board. For now, rest
assured that this wirebridge
can be left out without any problems.

Greetings and happy soldering, Jaco Sloof

p.s: Sent to the list too, maybe there are people that were workking on
this.. (you never know right? naaah, its just a shameless plug.. sorry)
--- Andrew Ison <andrew.ison at ntlworld.com> wrote:
> The attached file is includes a section of your ASM VCO on strip board,i am
> having some trouble with the strange markings for one IC's output,it seems to
> go to the plus rail and then off to the Earth rail from one pin of the
> IC,only the earth lead has a strange marking that i cannot fathom.
> Thank You,
> A.Ison.
> 

> ATTACHMENT part 2 image/bmp name=untitled2.bmp




	
		
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