I'm quite impressed with "Express PCB". They offer two, free, software packages that interlink.
First you draw the schematic and label the components and pins, then you move to the pcb program and draw the components and pins. What's really cool is the way the pcb component pin pads glow dark blue to indicate that they're on the same trace -- just highlight a soldering pad. Amazing. From there, you simply arrange and connect the pins to the proper trace.
I ordered 6 boards at a cost of $140.00. This is less than the original $169.25 because I reduced the size of the board considerably -- double sided copper boards allow such flexibility, just wonderful. They aren't masked or silk-screened, just plated through holes and tinned. I will probably be redesigning a bit here and there, so I'll just save the big money for the second generation.
This is great fun! What a interesting time to be alive.
They'll be here Tuesday the 7th.
Hoping everyone is well,
John
First you draw the schematic and label the components and pins, then you move to the pcb program and draw the components and pins. What's really cool is the way the pcb component pin pads glow dark blue to indicate that they're on the same trace -- just highlight a soldering pad. Amazing. From there, you simply arrange and connect the pins to the proper trace.
I ordered 6 boards at a cost of $140.00. This is less than the original $169.25 because I reduced the size of the board considerably -- double sided copper boards allow such flexibility, just wonderful. They aren't masked or silk-screened, just plated through holes and tinned. I will probably be redesigning a bit here and there, so I'll just save the big money for the second generation.
This is great fun! What a interesting time to be alive.
They'll be here Tuesday the 7th.
Hoping everyone is well,
John
I also noticed:
Should anyone choose to use the pcb artwork I introduced earlier, they would be wise to double check the pin-outs on the trim-pots -- they are reversed. Sorry.
The correction is easy, just reverse the pin footprint and extend the appropriate traces.
John
ahh, the joys of prototyping...
Should anyone choose to use the pcb artwork I introduced earlier, they would be wise to double check the pin-outs on the trim-pots -- they are reversed. Sorry.
The correction is easy, just reverse the pin footprint and extend the appropriate traces.
John
ahh, the joys of prototyping...
Can anyone tell me the consequences of using a 10pF cap in the feedback loop vs. 5pF as suggested by Nelson Pass?
If 5pF is the only way to go, and I can only find 10pF, do I create 5pF by running a pair of 10pF caps in series?
I'll keep looking for the answer, or the correct part, but would love some feedback...
sorry for the pun.
John
If 5pF is the only way to go, and I can only find 10pF, do I create 5pF by running a pair of 10pF caps in series?
I'll keep looking for the answer, or the correct part, but would love some feedback...
sorry for the pun.
John
carpenter said:Can anyone tell me the consequences of using a 10pF cap in the feedback loop vs. 5pF as suggested by Nelson Pass?
If 5pF is the only way to go, and I can only find 10pF, do I create 5pF by running a pair of 10pF caps in series?
I'll keep looking for the answer, or the correct part, but would love some feedback...
sorry for the pun.
John
Hi John,
As usual Choky is right.
And from the ZV4 article:
"C8 and C10 are simply high frequency bypass capacitors. Usually the circuit will work fine without them, but they provide a nice margin for stability. Similarly with C12, which trims the high frequency response so as to avoid peaking at high frequencies. Digi-Key doesn’t have 5 pF caps anymore, but I have listed 10 pF parts in the parts list. You can buy 2 and put them in series to form a 5 pF capacitor. Alternatively, you can twist two fine insulated wires (like those used in wire-wrap construction) together at a length of about 1.5 inches and get about 5 pF. This technique has the advantage that you can start out too long and trim it with a pair of scissors while watching the square wave of the amplifier."
Cheers,
Dennis
On Friday the 10th I experienced a rather severe heart-attack; my first and hopefully my last. I'm on 8 or 9 different meds and they're sapping my drive and enthusiasm. I can't believe it...
If someone sees me writing something stupid regarding Nelson's sweet, little ZV7-T , please feel free to offer corrections.
Best regards to my fellow diyers,
John
A public service announcement: should you find your left collar bone, your left shoulder blade, and your left triceps aching... and perhaps you feel a bit winded, don't sit there making up excuses as to what on earth you did to get so sore. Go to the ER immediately. I chose to go back to work... dumb idea!
If someone sees me writing something stupid regarding Nelson's sweet, little ZV7-T , please feel free to offer corrections.
Best regards to my fellow diyers,
John
A public service announcement: should you find your left collar bone, your left shoulder blade, and your left triceps aching... and perhaps you feel a bit winded, don't sit there making up excuses as to what on earth you did to get so sore. Go to the ER immediately. I chose to go back to work... dumb idea!
You guys are the best; I love you.
John
On the bright side, I now have all the time in the world to digest Nelson's articles and tinker with his prototypes.
I listened to my sound system last night for the first time in a week; music never sounded so sweet... you can't believe how much my appreciation for the simple things has grown.
John
On the bright side, I now have all the time in the world to digest Nelson's articles and tinker with his prototypes.
I listened to my sound system last night for the first time in a week; music never sounded so sweet... you can't believe how much my appreciation for the simple things has grown.
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