Quarter Inch Tape Formats

[af024]

aka 'Tapes Recorded Backwards'

I was searching for an old thread entitled, ‘Tapes recorded backwards’ circa 2007, but alas it seems to have disappeared. Thank you for looking for it Graham – much appreciated.

It’s just that I think I’ve spotted a couple of things that weren’t quite right with one of my postings (better late than never eh).

Essentially I think I got the grouping of the tracks for 8 track cartridges wrong, and I also missed out the 8 track quad format.

Whilst I was reviewing it all again, the penny has finally dropped about the rec/pb sequence for 4 track. Once upon a time I had a Grundig TK23 and an Elizabethan LZ34 (still do have the LZ34 in fact) and I’ve only just realised that one or other of the manufacturers went against convention.

If we assume that tracks are numbered from top to bottom, then you might think it logical to record in that order, but I don’t think that the Grundig did. At least it didn’t if you took the numbers on the track selection switch to mean the conventional order. The Elizabethan LZ34 did.

The first photo shows the Grundig TK23. The switch is labelled ‘1-2’/’3-4’ and ‘D’ (presumably ‘D’ meant ‘dual’ i.e. both tracks in the direction of travel are mixed together?).

The second photo is of the Elizabethan LZ34. The switches are labelled '1-4' and '2-3'.

(sorry about the grainy photos by the way).

On the basis that leaving a switch in the same position keeps the same part of the head connected, then it follows that turning the tape over to pass in the other direction will result in a track being laid down that’s located mirror-imaged (across the centreline) to the track previously laid down.

So if we make reference to the Elizabethan switches and assume that 1-4 is pressed down throughout, the first pass will be in track position 1 (top of the tape) and when the tape comes to the end and is fed back into the machine, track 4 will be laid down (bottom of the tape).

So if you want to record in conventional track order on the Elizabethan, you’d:-

Press 1-4 in and record 1
Press 2-3 in and record 2
Leave 2-3 pressed in and record 3
Press 1-4 and record 4

All straightforward, apart from when you get to the Grundig.

Clearly ‘1-2’ as marked cannot be referring to conventional track order. It must actually be 1-4 since the same part of the head is connected for the second tape pass.

What I now find amusing is that way back when, I knew there was something amiss between to two machines somewhere, but bizarrely, I thought it was the Elizabethan at the time. I even used some of that 1970s Dymo tape to re-assign the Elizabethan switches and tips screen printed into the top cover for goodness sake. How wrong was I!? It was the Grundig that was wrong!

So if you wanted to lay tracks down in conventional order on the Grundig, you’d have to go like this:-

Select 1-2 in and record 1
Select 3-4 in and record 2
Leave 3-4 selected and record 3
Press 1-2 and record 4

(I think!)

I’ve tried to show the order difference on the updated document (attached to this thread) and I’ve also dabbled with the 8 track cartridge area.

If anyone spots any problems or has any suggestions then please shout.

If nothing else, it does at least demonstrate the confusion in all the different formats. It’s even more of a nightmare when you have a tape of mixed formats!

Confused? You will be!

Regards,

Andy

[af024]

.. and the document in question ..

[paulsherwin]

I think the tracks on the tapes were all the same, but some manufacturers numbered them differently.

Cassette tracks were different because Philips wanted a stereo recording to play back correctly on a mono system, which wasn't possible with the quarter inch arrangement.

[TonyDuell]

Philips normally numbered the tracks 1 (forthest from the deck) to 4 (nearest the deck) on reel-to-reel machines. The selector switch had (at least) the settings 1-4 and 3-2

The normal way to record all 4 tracks seems to have been

Select 1-4, record track 1
Flip the spools over, record track 4 (which is now in the track 1 position)
Flip the spools over, Select 3-2, record track 3
Flip the spools over, record track 2 (which is in the track 3 position)

I would be surprised if it was different on other machines, even if they numbered the tracks differently.

[Restoration73]

Your list omits
1. 2 Track pro audio stereo has a wider guard band than 2 track euro standard stereo,
which has wider tracks and thus better s/n but higher cross talk.
2. Some early 2 track mono machines could record on either the upper or lower track
in one direction.
The standard reference work (AES) can be viewed ;
http://aes-media.org/historical/pdf/...stl-manual.pdf

[ricard]

Originally Posted by TonyDuell

Philips normally numbered the tracks 1 (forthest from the deck) to 4 (nearest the deck) on reel-to-reel machines. The selector switch had (at least) the settings 1-4 and 3-2.

Yes, this seems to have been the way all manufacturers except Grundig numbered them. The actual track arrangement is the same, it's just the numbering that is different. I'm wondering if there was ever any other manufacturer that had the same numbering as Grundig.

My speculation is that it was done that way in attempt to make it simpler for the user. It would seem logical when recording a four track mono tape first to record tracks 1 and 2, and then 3 and 4. Many if not most users would not care which order the tracks were actually laid out on the tape, so from a user perspective I suppose it made sense.

Other slightly unusual numberings I've seen: Old reversing two-track Grundig machines such as the TK819 call the tracks I and II, rather than for instance forward and reverse direction.

1960s Tandberg stereo machines (models 6, 7 and 12) call the tracks 'CH 1' and CH 2', with no mention of the track number. Later on they went to the more logical L and R, as many machines in the stereo era were labeled, with no indication of the track number.

[af024]

Thank you for your input everyone. I see the arguments, but if manufacturer's didn't stick to the same numbering convention, you'd end up with confusion when trying to play back a pre-recorded 4 track 1/4" tape which had the track numbers listed in conventional order for everything that was recorded on it. I guess that's what did my head in (pardon the awful pun) when I was young as the 'track' numbering of programmes just didn't tally between the two machines I've mentioned.

I wasn't aware of the two formats you mention Restoration73 - interesting.

Yes I see the logic with the cassette Paul.

I don't really know what the official recording sequence was TonyDuell. For me I had just assumed the following:-

Press 1-4 in and record 1
Press 2-3 in and record 2
Leave 2-3 pressed in and record 3
Press 1-4 and record 4

.. but the other sequence could be equally valid of course.

Yes Ricard, I guess it was just down to numbering. Strange how different manufacturers had a different take on it though eh? The track I and II plus CH1 and CH2 idea is also interesting.

[mole42uk]

I have a 1950’s Grundig 700L ‘Reporter’ which, from new, records half-track quarter-inch tape on the bottom track. The heads are designed this way. It makes it rather difficult to move tapes onto another machine although speeds and recording levels are otherwise standard.

[Tractorfan]

Hi,
Years ago, a friend of mine, whose grandmother was German, asked me to play some tapes of hers. They were recorded on the bottom track, so I had to lower the heads on my ancient Brenell a quarter of an inch. It worked a treat, and we transferred the recordings into cassette (I did say it was years ago! )
I wondered what sort of machine it was, so probably a Grundig.
I'm assuming that using the bottom track was the standard in Germany back the fifties?
Cheers, Pete.

[Ted Kendall]

The German standard was used on Grundigs up to 1955 or thereabouts (500/700) - early examples of the TK820 were to this standard but had a bi-directional transport, so a head transposition service did a roaring trade for a while. The head face was high enough to scan either track just by changing height - assuming the head hadn't worn too much. The TK5/8 series and on were top track from the off.

[barrymagrec]

Originally Posted by mole42uk

I have a 1950’s Grundig 700L ‘Reporter’ which, from new, records half-track quarter-inch tape on the bottom track. The heads are designed this way. It makes it rather difficult to move tapes onto another machine although speeds and recording levels are otherwise standard.

When I was about 14 I put a half track head on an EMI TR50 full track machine, in order to save tape. Since I had no knowledge of standards I fitted it in the lower track position as it was mechanically easier, I also spaced down the erase head.

This all worked fine until I was given a Collaro Studio Deck and found all my tapes played backwards.....

[TIMTAPE]

Originally Posted by paulsherwin

I think the tracks on the tapes were all the same, but some manufacturers numbered them differently.

Cassette tracks were different because Philips wanted a stereo recording to play back correctly on a mono system, which wasn't possible with the quarter inch arrangement.

That's true. The US Library of Congress also used a four track mono compact cassette format for the blind and print handicapped. It ran at half standard cassette speed and in other ways was a scaled down version of the 1/4" four track format, giving a total playing time of over 6 hours on a standard C-90 cassette.

The tracks were equally spaced for minimum crosstalk between adjacent tracks, but also, any residual speech crosstalk, being heard reversed, was unintelligible and so listeners tended more easily to tune it out.

The format was also used in the UK to eventually replace the Clarke and Smith cartridges for the blind which used 1/4" tape on 3" reels and with 6 tracks, giving over 13 hours on one cartridge.