TELECOM Digest OnLine - Sorted: Re: Very Early Modems

Re: Very Early Modems

Scott Dorsey (
24 May 2005 11:49:49 -0400

Tony P. <> wrote:


> So the carrier was on tape. How interesting.

> I guess at that point it was hard to stabilize a tube based
> oscillator.

It is much easier to stabilize a tube oscillator than it is to
stabilize a mechanical device like a tape machine. The old HP 200CD
bench oscillator from the fifties is nearly as stable as the modern
bench gadgets once it warms up.

The tape in this device is almost certainly being used to store a
varying carrier, for encryption purposes.


"C'est un Nagra. C'est suisse, et tres, tres precis."

Post Followup Article Use your browser's quoting feature to quote article into reply
Go to Next message: Kenneth P. Stox: "Re: Looking for a Model 15 or 19"
Go to Previous message: John R. Levine: "Re: Why Does it Take So Long?"
May be in reply to: "Very Early Modems"
Next in thread: Scott Dorsey: "Re: Very Early Modems"
TELECOM Digest: Home Page