Iron - a small note about improving modem communication - a simple RC filter.

----==== H A R D W A R E --- IRON Z O ====----

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Today, due to the lack of materials on this topic,
directly related to specs, a small note about improvement
modem connection. Source - Mike McCauley 'Modem Noise Killer'.
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The diagram below is the simplest
RC filter that reduces noise and increases speed
data exchange. Due to the variety of operating conditions of our
telephone networks, two trimming resistors were introduced.
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                       SETUP

1. It goes without saying, assemble the circuit and connect it like this,
as shown in the picture.
2. Try to contact any BBS with which you have
Previously there were problems (such as noise - ed.).
3. Assess the quality of communication and the level of noise on the line.
4. Adjust the filter with resistors R1 (coarse) and R2 (fine)
   if there are no differences, then most likely this is the best
   position of the regulators.

╔══════════════════════════════ ══════════════════════════════╗
║ Scheme 1. ║
║ >─────────┬─────────────── ─────────────────────────< ║
║ ═╪═ C1: 1..1.5 uF * 200 V ║
║ L │M ║
║ AND ┌>█ R1: 10 KΩ O ║
║ N └─┤ D ║
║ AND ┌>█ R2: 2 KOhm E ║
║ I └─┤ M ║
║ █ R3: 100 Ohm; 0.25 Watt ║
║ >─────────┴─────────────── ─────────────────────────< ║
╚══════════════════════════════ ══════════════════════════════╝