Magnacord 1024 Tape Recorder

Brooke Clarke 2000 - 2022



Tape Recorder

Two Parts

Tape Handling

The motors on the feed and takeup reels are constant torque.  For compliance there is a tape tension swing arm between each reel and the capstan that drives the tape.  The capstan has a massive flywheel attached to lower the Flutter and Wow.

The free standing tape recorders used with computers are optimized for the highest possible speed of access.  They can not afford the mass of the tape tension swing arms and have replaced both of them with a small elevator shaft like compartment where the tape hangs.  There's a control system that drives the reels to maintain the loop in the elevator compartments.

Adjustments

Both Record and Playback electronics each have adjustments to allow matching bias level and equalization to the particular tape being used.  I did it using a single audio tone.  Later read a paper suggesting that multiple tones should be used to come closer to simulating real inputs.  The idea is that the input signals act like a bias oscillator for other input signals.

Manuals and documents

Reel2ReelTexas Analog Reel To Reel Tape Recorder OnLine Museum - now the home of this recorder

Patents

2245286 Electromagnetic sound recording, Marzocchi Luigi, Priority: Jun 26, 1936, Pub: Jun 10, 1941, 360/84, 369/97, 360/83, 346/139.00A, 360/122 - scanned mag tape recording   referenced by 91 patents
2461368
Magnetic transducing apparatus utilizing a helical sound trace, William E Bradiey, Philco Corp, Filed: Dec 19, 1944, Pub: Feb 8, 1949, 360/29 - wire recorder.  They had problems with wire rotation.
2499699 Wire and tape driving means, Russell J Tinkham, Magnecord, 1950-03-07, - without using sprocket holes - capstan drive shaft (13) is hard, pinch rollers (14 & 15) are soft.
2499700 Magnetic recording and reproducing apparatus, Russell J Tinkham, Robert L Landon, Magnecord, 1950-03-07, - endless tape in box
2698875 Plural track magnetic recording and/or reproducing apparatus, James H Greenwood,
Magnecord, 1955-01-04, - 6 tracks - "One application of the invention is in the field of recording television (video) signals for subsequent reproduction. Another application of the invention is in the field of recording military and communication signal currents of a frequency both within the standard video band as well as of frequencies above that band which are considered as falling within the video frequency range."
2796571 Electric motor, William L Dunn,
Magnecord, 1957-06-18, - "... single-phase alternating-current machine that can be used as a synchronous motor, a variable speed motor, or a variable speed motor synchronized by external Synchronizing pulses." i.e. a stepper motor
2956114
Broad band magnetic tape system and method, Charles E Anderson, Ray M Dolby, Charles P Ginsburg, Jr Shelby F Henderson, Ampex, Oct 11, 1960, 360/30, 386/E05.9, 386/335 - helical scan video  

Related

Telephone \ Poulsen Telegraphone

Links

Back to Brooke's Personal home, PRC68, Military Information, Electronics