Re: Persistence seems lacking...

Fred Piering

Hi Jim:
I remember that, but things were a little simpler then too.
Today with some of my clients, I get schematics that have 38 capacitors all shown in a string in the upper left hand corner.
They are the bypass capacitors for all the IC's. I think they do that to make the schematic less cluttered, especially when you have a 100 pin FPGA.
But...when I was designing and working with the draftsmen to make printed wiring boards, I trained them that the schematic told a story.
If I placed a bypass capacitor directly to the pins on an integrated circuit, that told them, place it right at the pins. If the capacitor connected to one pin and had a ground symbol on the other, it said put it near.

On 9/9/2019 9:36 AM, James Daldry W4JED wrote:

Hi, Fred

Back in tube days you commonly found all the filaments in the lower right hand corner of the schematic. In many cases the power transformer 6.3 volt winding ended in 2 arrows. It was assumed that if you were working on the equipment you knew what a filament was.



On 9/9/19 9:29 AM, Fred Piering wrote:
Any schematic that does not show all connections is incomplete (HA).

On 9/8/2019 9:59 PM, Bob Macklin wrote:
It's common practice with solid state electronic not to show the power pins on the chips.
Bob Macklin
Seattle, Wa.
"Real Radios Glow In The Dark"
----- Original Message -----
Sent: Sunday, September 08, 2019 10:00 AM
Subject: Re: [QRPLabs] Persistence seems lacking...

One of the problems with the schematics given with the kits is not all of the connections are shown... For instance, on the QLG1  GPS board for the U3s, there are no connections shown for power and ground for IC1. On the Relay-switched LPF kit there are a gaggle of connections marked with X for jumpers/external connections, etc that make it very unsuitable for debugging... Although most commercial radio schematics have a whole lot more detail, they are much easier to read as all the connections to any plugs/jacks are routed to the side and grouped by the plug/jack in numerical number, and jumpers are shown in the default positions, etc.


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