3 3/4 IPS analogue tape question

[Matt Syson]

Hi
Running the machine at 30 Hz 'mains' will almost certainly saturate the mains transformer which will then most likely make everything hum.
The main argument would be whether the capstan motor is synchronous to the mains supply or whether it is servo controlled.
Capacitors won't care what the frequency is.
Matt S

[theblue1]

Thanks for the additional info, Matt!

I wish I had a better grounding in electrical engineering.

(Inadvertent pun grudgingly acknowledged.)

[theblue1]

Originally Posted by Rick Sutton

Yeah, even though I knew the 2340 as a 3-3/4 and 7-1/2 machine it wouldn't surprise me that there might have been other versions......hey, that was a long time ago.
Cheers,
Rick

[...]

It was a long time ago. But the image of that 2340, which might as well be my old deck cleaned up, definitely brings back fond memories. I followed the 2340 with a couple of 3340 'push button' decks... but it was that old 'knife-switch' deck that was my true love. I wore the heads down to next to nothing, I'm afraid... I still have a relatively low mile 40-4 but I haven't fired it up in years. And that makes me a little sad...

[Matt Syson]

Hi
I transcribed a colleague of my wife's tape a while back using my TEAC X10.
The tape was about 40 years old and very fragile, it snapped if I let the reels take up any slack themselves. The hum to signal ratio was bad (more recorded hum than there was signal) and the speed was not constant (recorded).
When in digital I could use 200 Hz filter (shelving) to get rid of the hum (it was spoken word).
There was no treble!
I always wanted a 3340 but could not afford or justify it.
I also wanted a PCM F1 Sony digital convertor, bought the Beta video which worked well for over 20 years but couldn't afford the convertor. Now I got a convertor but the Beta died a few years ago!
Matt S

[theblue1]

You got a single Sony Beta deck to last for twenty years?!?

You're the guy I want babying my old gear when I'm gone. Too bad I already got rid of my 2340 and my two 3340s.

[rocksure]

Originally Posted by Matt Syson

Hi
I transcribed a colleague of my wife's tape a while back using my TEAC X10.
The tape was about 40 years old and very fragile, it snapped if I let the reels take up any slack themselves. The hum to signal ratio was bad (more recorded hum than there was signal) and the speed was not constant (recorded).
When in digital I could use 200 Hz filter (shelving) to get rid of the hum (it was spoken word).
There was no treble!
Matt S

That sounds very similar to the sound of the tape I just transferred. It dirtied up the heads alot, had lots of hiss and hum and all the treble was gone. It was hard work to get anything useable off it ( recorded at 1 7/8" part of the time and 7 1/2" the rest of the time). Mostly spoken word stuff.

[Matt Syson]

Hi
Admittedly it was only domestic use but it worked well and gave a good picture compared to a new VHS machine (over 10 years later). Main problem it liked the tapes so much they wouldn't come out without help.
Matt S

[MessianicDreams]

Okay, so after having digitised one of the tapes, I came across something very strange. When the two channels were recorded in, this is what I was left with:


On the L side, music & talking (its a recording of a radio show) playing correctly.

On the R side, music & talking playing correctly (different from what's on the L - part 1 of the radio show or whatever).

However, almost exactly half-way through the tape, someone has recorded over the top of what we're listening to, but this new recording is playing backwards. For 4-5mins, you can hear both recordings at the same time.

Anyone have any ideas about this? is it just the way it was recorded, or is this because we're running the tape on the wrong machine?

As you can tell, I know nothing about this kind of tape

[Matt Syson]

Hi
Your luck has kind of run out!
It was recorded on a 'domestic' 2 track machine with 4 possible tracks (2 in each direction).
Your 'pro' machine is expecting 2, half tape width tracks but the way it is recorded you have 2 quater tape width tracks on one side then you turn the tape over and you then get 2 more tracks.
Think of 4 'stripes' across the tape. On your machine it is playing tracks 1 and 2 to give Left (or track 1) and 3 and 4 to give track 2 (Right).
The original machine would be recording on stripe 1 and 3 going one way. When you turn the tape over the 'top' stripe 1 becomes 4 and 3 becomes 2, confused yet?
Basically you need a quarter inch 4 track head rather than what you have which is a quarter inch 2 track head.
Time to find and dust off a 'domestic' machine.
Matt S

[Rick Sutton]

Originally Posted by MessianicDreams

Okay, so after having digitised one of the tapes, I came across something very strange. When the two channels were recorded in, this is what I was left with:


On the L side, music & talking (its a recording of a radio show) playing correctly.

On the R side, music & talking playing correctly (different from what's on the L - part 1 of the radio show or whatever).

However, almost exactly half-way through the tape, someone has recorded over the top of what we're listening to, but this new recording is playing backwards. For 4-5mins, you can hear both recordings at the same time.

Anyone have any ideas about this? is it just the way it was recorded, or is this because we're running the tape on the wrong machine?

As you can tell, I know nothing about this kind of tape

Yeah, pretty common with old tapes. Many of them have been re-used and can have a variety of track width and speed/direction combinations on them. I use a Techniques RS1500 for these duties and with 3 speeds and 2 different playback heads I have a pretty good shot at sorting these issues out.