Patchwork Reloaded: Circuit Optimization and Board Layout.

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Those fracking weeds again...they really got bad last year (breakup time, again - neither one of us were doing a damn thing around here out of spite and the weeds saw this as their golden opportunity to move in and take over.
My backyard late last year:

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Here it is today. The bald patch is where she took out the things that she didn't want (furniture, etc that I either owned or certainly could have used) and BURNED it. Ah, the battles we wage in the name of love...

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Many different bloods flowing in these veins but I'm not sure if there is any "Italian greaseball" - could be. Who knows what's tangled in the roots of the family tree.

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Doing some finishing touches - made the top attach with no visible fastenings. Metal pins slip into the front plate and I added a small aluminum angle to the bottom of the top to attach to the back plate. Solid and elegant.

I weighed it using my bathroom scale with it in my arms (it occurs to me it's heavy, lugging it around). It's 52 pounds, which is more than I expected. A sum of the parts I guess.
 
Hey, John. I noticed, that there is another newer version of the PCB. Could you post some gerber files, so that we can make the board in a factory, you promised me last time, but I forgive you, as long as the newer version is better! 😀
 
Thanks Peranders,
I went from knowing nothing (at the beginning of the Patchwork project) to knowing enough now to put it all together without worrying that it'll burn the house down!
Still, I know nothing 🙂

Ooops! Kalmara I missed your post. I'll get the Gerbers together and post them here. Stay tuned
 
Lead spacing for these caps?

CAPACITOR, 100nF C4, C16, CZ
CAPACITOR, 100pF C18
CAPACITOR, 1uF C9, C7, C8
CAPACITOR, 2.2uF C6
CAPACITOR, 220pF C10

And the 2SA1381, what hFE do I need?

C4, C16 are ceramic bypass - NPO/COG. Pin spacing on board is 5mm.

CZ can be ceramic or film. Board spacing is 5mm.

C8, C9 are film. 15mm lead spacing.

C7 is film like this 10mm lead spacing.

C6 is similar to C7. It has multiple pin spacing, from 5mm to 16mm.

C10 can be silver mica or NPO/COG ceramic (what I'm using). Pin spacing is 5mm and 7.5mm

Get the "F" class for 2SA1381.
 
I'd like to use X7R bypass caps because I already have them (and they're much, much cheaper). Do you think that downgrading will result in a tangible performance drop?

How about C18?

For C6, I'm assuming it's 5mm, 12.5mm, and 16mm?

Can I replace the 1N4148 with 1N4004 (higher specs)?
 
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I'd like to use X7R bypass caps because I already have them (and they're much, much cheaper). Do you think that downgrading will result in a tangible performance drop?

How about C18?

For C6, I'm assuming it's 5mm, 12.5mm, and 16mm?

Can I replace the 1N4148 with 1N4004 (higher specs)?

X7R for bypass are fine - I certainly couldn't hear a performance drop (maybe because it doesn't exist 😉 )

C18 is not on the design. See latest board layout above.

1N4004 will work as well.

C10 looks like it only has one pair of holes, and it seems to me that the pitch is something like 3.5mm?

Are there any caps whose tolerances are crucial, besides C10?

Again, see latest board layout.
Nothing is critical. 10-20% for everything is ok (nice to have C5 5%). C10 is for input RF, tolerance is not critical.

If you are making a PCB then I advise that all the caps should have multi pin pitch options.

Not really needed, these are common sizes and really wouldn't be a problem sourcing them. Laying out a board is hard enough without allowing for every conceivable cap size.
 
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