One comment on that -- it could be anything from a HP unit circa 1950 onward. For instance if you're
hearing this between 1K and 10K, that's because most oscillators had a switch for 1x, 10x, 100x of a
frequency that was dialed in on the rotary control. Function generators were typically push-button
and 1x, 10x, 100x was standard. Recording consoles and tape decks like the Technics RS-1520 or the
Otari MX5050 (at least the 4track version I have) had switches for 1K, 10K tones (rotary on a
Technics, pushbutton on an Otari). I've seen recording consoles with pushbuttons for 100, 1K and 10K
and other tones. Older-school studios just used an external oscillator plugged into a slate input.
Basically, the way I've always operated was never to set speed/pitch from slate tones. If you're
lucky they'll give you an accurate 0-VU level and that's about it. Again, if you're lucky, you can
use a scope and set azimuth from them (that's assuming they were recorded just before the program
content was recorded, on the same deck, and the deck was azimuth-aligned differently between tones
and program content -- not always the case).
-- Tom Fine
----- Original Message -----
From: "Jim Sam" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, January 27, 2011 1:58 PM
Subject: Re: [ARSCLIST] Test tones circa 1978
I should add that I'm interested in this due to tape that was recorded
at 7.5 ips, 250 nWb/m. The tone sequence is not standard, with tones
changing abruptly as if a button was pressed, rather than a dial
On Thu, Jan 27, 2011 at 10:40 AM, Jim Sam <[log in to unmask]> wrote:
> Does anyone know how much test tone generators varied circa 1978?
> I know not to expect digital accuracy. For example, I would not
> expect a 10.00 kHz tone, but how much leeway was there? +/- 0.25kHz,
> +/-0.5 kHz, +/-1.0 kHz, etc.?