I'm gathering from what I'm skimming here that Recordio-style machines have a frequency range topout of about 8kHz, running at 78 or at 33-1/3 rpm. Am I getting this right?
I've noticed that transcribing old 78s or AM radio broadcasts from before about 1945 usually means cutting everything over 5k; the rest is just noise. Later AM and the best of pre-"high fidelity" recordings usually have an 8k topout. So that's a number I can work with, based on experience. Latter-day OTR and music sound OK in that range. (I once salvaged an 80s live tape by using a 10k rolloff; nobody missed the higher frequencies!)
I made a simple test-tone disc for checking equipment (ten seconds at 0dB over frequencies from 10Hz to 20kHz). With my Airline recorder, the lights stopped reading over 6kHz, even though the tones still carried over the speaker. So I have to wonder. Who can tell me more? How are these machines for wow and flutter, and such? Thanks.
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ZephyrRadio
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