15th May 2019, 12:26 pm | #101 | |
Octode
Join Date: Mar 2006
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Re: Reel to reel revival
Quote:
This still seems to be minor problem in the sense that it should be fairly easy to fix should one want to start manufacturing them again. I'm thinking of the Tandberg 9100X/9200XD which doesn't have motion sensing, yet has delays in the switching electronics so that when going from wind to stop there's a delay before play can be started. It's usually fairly fail safe (although there are are situations where you can trick it). Today one would probably have a small microcontroller handling all sorts of logic work within the machine anyway. |
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15th May 2019, 7:17 pm | #102 |
Rest in Peace
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Re: Reel to reel revival?
If I had a bit more spare time I would be very tempted to try and build one, just for the engineering challenge. I have a couple of friends who could turn small components on a lathe for me, and I think I have most of the electronics to hand. Wow and flutter could be a bit of a problem though.
Alan. |
15th May 2019, 10:20 pm | #103 |
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Re: Reel to reel revival?
In view of the probable quantities involved in a revival high quality reel-reel machine, diecasting wouldn't be justified. Water-jet cut aluminium plate would make a very good substitute and could be a feature if linished and anodised.
The older Truvox decks had a plywood plate with a formica surface. Motors, headblocks etc mounted onto it. THe same could be done today. A jet cut plate from an NC cutter could look rather good. A stud welder could avoid screw heads on the top. It could be done by someone with some machinery and the inclination. I doubt it would be viable as a business venture. Could be fun. David
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15th May 2019, 11:28 pm | #104 |
Octode
Join Date: Sep 2017
Location: Bristol, UK.
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Re: Reel to reel revival?
"The older Truvox decks had a plywood plate with a formica surface. Motors, headblocks etc mounted onto it. THe same could be done today."
I once had one of those Truvox plywood decks. It had warped horribly from the heat inside a previous installation by the time I got it! Good ventilation would be critical - perhaps less of a problem now we're more used to thermal design for solid state stuff. Mike |
15th May 2019, 11:31 pm | #105 |
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Re: Reel to reel revival?
I'd just have a nice thick aluminium plate made on an NC cutter. The plywood of the Truvox was OK until it warped, but the idea of a deck with motors etc attached to a single thick plate is OK.
David
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17th May 2019, 10:56 pm | #106 |
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Re: Reel to reel revival?
The biggest problem with reel to reel is that there were so many different formats and speeds.
2 track, 4 track, ¼ track, ½track, stereo, mono, speeds from 15/16, 1⅞, 3¾, 7½ and possibly 15 IPS. for the more discerning, NAB or IEC equalisation. Dolby or non dolby. The combinations are endless. |
18th May 2019, 1:58 pm | #107 |
Heptode
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Re: Reel to reel revival?
From 1979 to ca 2010 I had a B77 2 track 7.5 / 15 ips NAB.
I judged this to be best for making high quality recording from R3 and the Alan Dell big band / danceband days on R2. It sounded pretty good with a Quad FM3 source.
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18th May 2019, 3:58 pm | #108 | |
Heptode
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Re: Reel to reel revival?
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18th May 2019, 4:11 pm | #109 |
Octode
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Re: Reel to reel revival?
Don't forget there were also different versions of CCIR/IEC as time went on: originally 7.5ips = 100us & 3.75ips = 200us, later this became 70us & 140us. Got a feeling it changed again later.
Then if you like pumping noises there was DBX. Finally, in the early days there was British or Continental tracking (whether top or bottom track was recorded 1st) Ooo I nearly forgot oxide in, or oxide out! Last edited by wd40addict; 18th May 2019 at 4:18 pm. |
18th May 2019, 4:48 pm | #110 | |
Nonode
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Re: Reel to reel revival
Quote:
"I've an opera here that you shan't escape on MILES and MILES of recording tape!" Martin
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18th May 2019, 5:01 pm | #111 | |
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Re: Reel to reel revival
Quote:
At 7.5 ips (the fastest speed commonly used for domestic recording, 15 ips was very uncommon) that's 8448 seconds of recording. So about 2 hours 20 minutes. But that is just one mile of tape. I think for 'miles and miles' you'd need to have the entire Wagner Ring Cycle.. More seriously, how long was the longest commonly used tape (in miles)? |
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18th May 2019, 5:22 pm | #112 |
Octode
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Re: Reel to reel revival?
Standard 10.5 inch NAB reels take 2400 feet of standard play tape, that`s 32 minutes at 15ips. 11 inch platters were available with 3000 feet of tape, if you were confident enough of your tape machine to risk it all dropping on to the floor.
14 inch NAB reels were used on instrumentation machines but rarely for audio, apart from voice logging. The Solti recording of the Wagner Ring Cycle was recorded at 30 ips and runs to about fourteen and a half hours so about 25 miles of tape. |
18th May 2019, 6:43 pm | #113 |
Heptode
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Re: Reel to reel revival?
I'm sure it's been thought of already by more knowledgeable people than me but what about using a different method of reading magnetic info from the tape (assuming no tape head available) such as a hall effect device?
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18th May 2019, 7:10 pm | #114 | |
Heptode
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Re: Reel to reel revival?
Quote:
I know little about the Hall effect ; but I imagine the transducer would have to have a high resolution contact point ( line ) with the tape.
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18th May 2019, 10:54 pm | #115 |
Octode
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Re: Reel to reel revival?
Technics apparently made a couple of cassette decks with hall effect playback heads. A brief search turned up this thread from a couple of years back from another forum:
http://www.tapeheads.net/showthread.php?t=28418 I remember reading about it in one of those 'which tape recorder to buy' type magazines at the start of the 1980s. One advantage was that the low end frequency response extended very far down; in essence the head by virtue of its design could read pure DC from the tape. ... except that reading more, it seams the head was based on MR ('magnet resistive' according to the owner's manual), which is not the same thing as the hall effect. Ah well, at any rate it was not a run-of-the-mill coil, laminations and gap type head. Yet more detail on this type of head and the connection with Philips and DCC here: https://www.tapeheads.net/showthread.php?t=8817 Last edited by ricard; 18th May 2019 at 11:02 pm. Reason: Read up some more on the Technics decks |
19th May 2019, 7:27 am | #116 |
Heptode
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Re: Reel to reel revival?
I don't knowif a Hall effect transducer creates it's own magnetic field? This would be a little undesirable!!
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19th May 2019, 8:14 am | #117 |
Dekatron
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Re: Reel to reel revival?
Somewhere I have a Hall effect head from the Telefunken M10A which used to sit in BH test room making test tapes. It has a narrow element set in a Tufnol surround. I've never tried it - might be fun to play with it...
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20th May 2019, 12:22 am | #118 | |
Octode
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Re: Reel to reel revival?
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20th May 2019, 5:44 am | #119 |
Octode
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Re: Reel to reel revival?
The multiple speeds and track formats over made open reel very versatile. Another format was 10.5 inch reels of LP 3600 ft tape running at 15/16 ips as a radio station logging format. The stereo machines recorded the mono radio programme on one track and on the other, the announced time from the free telephone time service in those days. "At the stroke it will be..." So an audible time code. It gave over 12 hours' recording time. Not hifi audio but enough to satisfy government requirements. I have a batch of such tapes from the late 70's.
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21st May 2019, 1:10 pm | #120 |
Octode
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Re: Reel to reel revival?
Just to keep the interest going, here are photos of the pages from Model Engineer, 1952, about making a tape recorder.
I only have the copies for parts 1 and 3, also needed is June 5th 1952. |