[elektor] Signal cleaner.

[XavSnap]

Hi,

Kicad project and Gerber files now available...

http://abandon.pcbs.free.fr/Elektor.htm

Have Fun...

[dessony]

XavSnap,

Excellent!

https://worldradiohistory.com/UK/Elekto ... 984-10.pdf

Look for this certain information: pages 10 - 45 to 47

Cheers,
DesSony

[David G]

Most interesting

Xav's link is to the project files are about the "ZX81 cassette pulse cleaner" from Elektor magazine (an electronics project magazine), which seems to be a Printed Circuit Board (PCB) that cleans up the tape signal

These are new(?) project files with which you can order a new board, or make your own

DesSony's link is to the 1984 article in Elektor about the board (PDF version)


related elektor issues:

• 1984 January: digital cassette recorder [DCR]

• 1984 May: DCR causes problems with a ZX81

• 1984 September: changes needed for the DCR to work with ZX81 [Hardware forum] (modify the ZX81, and modify the DCR)

• 1984 October: ZX81 cassette pulse cleaner [Hardware forum]

The "pulse cleaner" board seems like the ultimate solution and they say it works with other tape-saving computers like the IBM PC

[XavSnap]

Thanks DesSony and David,

It's the original PCB released in the issue 76 (1984 October). (David's tread)

Elektor was an international magazine published in English, German, French.

In India, the issue was released in 1984 November.

At the first look, this project is not optimized against radio frequency noises (unshield board) and need a heavy voltage converter...
It needs a serious update!

[XavSnap]

Erratum:

There is two errors in the wiring diagram: (the PCB/gerber circuit steal ok)

1) U3 & U4 are upset down and had to be placed as the article picture descriptions (was a wrong package in the wiring diagram).
2) R2 & R3 was wrong connected.

On the old BCP, juste place U3 by the downside and the U4 at the top side.
R2 & R3 are right on the PCB (Printed Circuit Board).

Gerber/Kicad Project updated.

[XavSnap]

Signal cleaner V2.
(in the same FTP directory)

Use the MP1584 to generate the -5v supply.
Just use a 5v power supply.

http://abandon.pcbs.free.fr/Elektor/Sig ... hemaV2.jpg

[XavSnap]

[1024MAK]

Looking good

Mark

[David G]

Signal cleaner V2

My understanding is that this creates a better (sharper) tape signal. Which is needed for tapes that cannot be read. From the original article:

programs that have been difficult to load in the past can now be loaded properly.

Which makes me think this "Pulse Cleaner" is not for recording, but for playing back tapes

When I looked at the article six weeks ago i somehow was thinking it was about recording rather than playback (as a continuation of the prior Elector article) ... but playback Pulse Cleaning makes more sense, because ...

Most tape player recorders work fine with an unmodified ZX81, although some seem to be sensitive to the volume/voltage of the signal. I seem to recall some ZX81s -- depending on the build tolerances -- had a weak tape out signal (and could be fixed by changing two internal resistors). For those having tape recording problems, will a smaller simpler tape signal pre-amp be a solution to recording a better signal? And if need to LOAD a tape that was previously recorded with a poor signal, this Pulse Cleaner is the solution