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Old 3rd May 2021, 3:27 pm   #39
G6Tanuki
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Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
Default Re: How much should one invest in tools to get in the hobby/occasional business?

It's worth remembering that you already have a rather good audio-frequency signal-generator and storage-scope both with frequency-capabilities extending well beyond the range of human hearing.

You're sitting in front of it. A PC soundcard with suitable software can generate, record, replay and display a whole range of waveforms.

In times-past I used a PC soundcard to generate CTCSS tones for 2M repeater access, to produce the two non-harmonically-related sinewaves for SSB linear-amplifier testing: there are downloadable 'test tone sets' available free from a multitude of places - you can put a lot of these on a 4Gb USB memory-stick and play them back using VLC, Audacity, Windows media Player or similar].

I also use an ancient PC as an automated "CQ-sender" on HF: just hit the spacebar and it sends 45 seconds of CQ.

I've also used a "swept tone' generated this way to explore sideband-filter passband shapes.

The soundcard input is similarly useful - you can capture audio and either record it for later analysis [this has proved useful in identifying intermittent problems which never seem to happen when you're watching the screen], use the PC as a frequency-counter, or as an oscilloscope [dual-trace if your soundcard is stereo!] to display waveforms or waterfalls.

[A waterfall is handy for identifying intermittent ultrasonic oscillations in amplifiers: I guess it could also be used tio explore wow-and-flutter on record-players/tape-decks?]

Again, even using a 'lossless' algorithm, it'll take days of capture to make a significant dent in the free-space of a modern hard-drive.

And i'd bet the accuracy of a typical soundcard's digitisation is as linear [or logarithmic if desired] as most 'scopes or signal-generators used by amateur/hobbyist repairers.


Look at your PC and see what test-gear it can replace!
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