Dictabelt speed

[Adrian Tuddenham]

Does anyone happen to know the official speed of a Dictabelt? It seems
to be around 6 inches per second or 30 belt revolutions per minute, but
there must be a proper specification somewhere.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[N_Cook]

Adrian Tuddenham <adrian@poppyrecords.invalid.invalid> wrote in message
news:1k8d39l.icacwfv97jyN%adrian@poppyrecords.invalid.invalid...

Does anyone happen to know the official speed of a Dictabelt? It seems
to be around 6 inches per second or 30 belt revolutions per minute, but
there must be a proper specification somewhere.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

If the Zapruder / Kennedy assassination recording is out there , is there
any repeated scratch/molding clicks to take timings off ?

Try posting to r.a.r.p ?

 

[N_Cook]

Adrian Tuddenham <adrian@poppyrecords.invalid.invalid> wrote in message
news:1k8d39l.icacwfv97jyN%adrian@poppyrecords.invalid.invalid...

Does anyone happen to know the official speed of a Dictabelt? It seems
to be around 6 inches per second or 30 belt revolutions per minute, but
there must be a proper specification somewhere.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Do you get involved with non-contact vinyl/wax reading via CD
laser/tracking/servo technology

 

[Jeffrey Angus]

On 9/29/2011 10:22 AM, N_Cook wrote:

Try posting to r.a.r.p ?

That would be rec.antiques,radio+phono or is
that a different group you had in mind?

Jeff

--
"Everything from Crackers to Coffins"

 

[N_Cook]

Jeffrey Angus <grendelair@aim.com> wrote in message
news:j623aa$22l$1@dont-email.me...

On 9/29/2011 10:22 AM, N_Cook wrote:
Try posting to r.a.r.p ?

That would be rec.antiques,radio+phono or is
that a different group you had in mind?

Jeff

--
"Everything from Crackers to Coffins"

yep


To OP, would that use shaded pole motor and then fixed gearing?

 

[Jeff Liebermann]

On Thu, 29 Sep 2011 15:07:40 +0100,
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:

Does anyone happen to know the official speed of a Dictabelt?

Which maker and what model?
They followed the same speeds at record platters.
ips time
15 15 min
7 1/2 30 min
3 3/4 60 min
1 7/8 120 min
However, I'm not sure of the times. There were also versions that
offered 4 channels per tape, which decreased the run time. For
example, the Kennedy tapes were 4 channel mostly at 3 3/4 ips, but
only ran for 15-20 mins.
<http://whitehousetapes.net/info/kennedy-tapes-overview#TECHNICAL_NOTES>

More:
<http://www.videointerchange.com/audio_history.htm>
Scroll down to "Dictabelt 1947".
12" circumference, 15 minutes play time, 3.5" wide.
The problem is I don't know how how many tracks per inch across the
3.5" wide belt. If you have a device, you can measure tracks per inch
or calculate it from the gearing.

It seems
to be around 6 inches per second or 30 belt revolutions per minute, but
there must be a proper specification somewhere.

30 rev/min = 0.5 rev/sec. At 12" per revolution, that's:
0.5 rev/sec * 12 in/rev = 6 in/sec.
Close enough to 7.5 ips.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Adrian Tuddenham]

N_Cook <diverse@tcp.co.uk> wrote:

Adrian Tuddenham <adrian@poppyrecords.invalid.invalid> wrote in message
news:1k8d39l.icacwfv97jyN%adrian@poppyrecords.invalid.invalid...
Does anyone happen to know the official speed of a Dictabelt? It seems
to be around 6 inches per second or 30 belt revolutions per minute, but
there must be a proper specification somewhere.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk



Do you get involved with non-contact vinyl/wax reading via CD
laser/tracking/servo technology

I recorded the wax test cylinders for Southampton University's optical
reading project; but I don't do any optical playback myself.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[Adrian Tuddenham]

N_Cook <diverse@tcp.co.uk> wrote:

Jeffrey Angus <grendelair@aim.com> wrote in message
news:j623aa$22l$1@dont-email.me...
On 9/29/2011 10:22 AM, N_Cook wrote:
Try posting to r.a.r.p ?

That would be rec.antiques,radio+phono or is
that a different group you had in mind?

Jeff

--
"Everything from Crackers to Coffins"

yep


To OP, would that use shaded pole motor and then fixed gearing?

Capacitor start/run motor with rubber idlerprimary drive; then pulleys
and a flat belt to the final drive roller shaft - so there's plenty of
slippage to give measurement errors.

Also, the machines I have seen in the UK have 60 c/s motors adapted for
50 c/s, which have very low torque and a high slip frequency on load.

(The only fixed gearing is between the drive roller and the leadscrew.)

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[Adrian Tuddenham]

Jeff Liebermann <jeffl@cruzio.com> wrote:

On Thu, 29 Sep 2011 15:07:40 +0100,
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:

Does anyone happen to know the official speed of a Dictabelt?

Which maker and what model?
They followed the same speeds at record platters.
ips time
15 15 min
7 1/2 30 min
3 3/4 60 min
1 7/8 120 min

I think you have misunderstood the type of machine I am enquiring about.

[...]

It seems
to be around 6 inches per second or 30 belt revolutions per minute, but
there must be a proper specification somewhere.

30 rev/min = 0.5 rev/sec. At 12" per revolution, that's:
0.5 rev/sec * 12 in/rev = 6 in/sec.
Close enough to 7.5 ips.

It issignificantly below 7.5 ips. I need to know the manufacturer's
specifications as I am developing a playback machine for archival work,
where comparison between the actual speed and the 'official' speed can
yield useful historical information.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[Jeff Urban]

Interesting dilemma you got there. I searched the web but then it
would be unreasonable to think you hadn't. I found something called a
memobelt which was supposedly the same or similar.

However in thinking about it, being a scribing machine of sorts, and
given the time frame I would think two things, well one.....

It is unlikely that the unit used a capstan. Crushing the media would
not be desirable.

As such that means the media speed would vary as it accumulates on the
reel, which we really cannot call a takeup reel because of the lack of
a capstan and pinch roller. I guess it would be called a drive reel
then.

I don't imagine alot of problems with this, because some things can
just be figured out. Now I have gone into wiki and as you probably
know the JFK assassination is recorded on this medium. The article I
read also states that there are references due to police calls which
do denote the time one way or another, but that data are better used
in fine tuning, it seems that you need more of a ballpark figure right
now.

As such I would attempt to take a picture of a section of this belt
media. In fact I would do it at the beginneing of a reel as well as at
the end. Since the information is scribed, like a phonograph record
groove, you should be able to figure out the speed by the length of
the modulation in the "groove".

It is logical to assume that they used the minimum speed possible for
intelligibility, therefore figuring the minimum bandwidth for speech
what do we have ? I would think that 600 - 4,000 Hz would be enough.
Looking at the groove should then give you an idea. The high frequency
limit is the key,. And remember they didn't have high compliance
Shibata stylii when this thing was invented. You may need quite a
length of it, run it through something for film or whatever, and use
magnification. Find the shortest "wavelength" undulations in the
groove you can, and assume it's a couple of Khz. Then you can figure
the IPS from there.

I wonder how you intend to pick this up really. Optically or with a
stylus ? I mean would you somehow fit a magnetic phono cartridge to
this whatchamacallit or let some type of LED and optical sensor array
do it ?

This intrigues me just because it is different, and the fact that I am
stil a Beta dood. I even have a one inch vodeotape hiding in the
basement, still waiting for a machine that can play it. I used to own
a Cartovision !, but I did buy it used.....

Data preservation and restoration is a real field of endevor, I mean
people do devote their carreer to it. I myself would pay money to have
what I have recorded on Beta for example in the old days. In fact I
even worked on one of those Technicolor VCRs. Actually eight
millimeter but not the Sony type that was standardized about a decade
or so later......

Aaaa, the good old days.

J

 

[isw]

In article
<1k8djs5.mfwbsv10hentqN%adrian@poppyrecords.invalid.invalid>,
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:

Jeff Liebermann <jeffl@cruzio.com> wrote:

On Thu, 29 Sep 2011 15:07:40 +0100,
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:

Does anyone happen to know the official speed of a Dictabelt?

Which maker and what model?
They followed the same speeds at record platters.
ips time
15 15 min
7 1/2 30 min
3 3/4 60 min
1 7/8 120 min

I think you have misunderstood the type of machine I am enquiring about.

[...]
It seems
to be around 6 inches per second or 30 belt revolutions per minute, but
there must be a proper specification somewhere.

30 rev/min = 0.5 rev/sec. At 12" per revolution, that's:
0.5 rev/sec * 12 in/rev = 6 in/sec.
Close enough to 7.5 ips.

It issignificantly below 7.5 ips. I need to know the manufacturer's
specifications as I am developing a playback machine for archival work,
where comparison between the actual speed and the 'official' speed can
yield useful historical information.

Any chance of there being any power-line hum in the recording? If there
is, that's your calibration. If not the fundamental, then maybe
harmonics ...

Isaac

 

[Jeff Liebermann]

On Thu, 29 Sep 2011 21:08:55 +0100,
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:

Jeff Liebermann <jeffl@cruzio.com> wrote:

On Thu, 29 Sep 2011 15:07:40 +0100,
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:

Does anyone happen to know the official speed of a Dictabelt?

Which maker and what model?
They followed the same speeds at record platters.
ips time
15 15 min
7 1/2 30 min
3 3/4 60 min
1 7/8 120 min

I think you have misunderstood the type of machine I am enquiring about.

Maybe. As I see above, it's called a Dictabelt. I used to fix those
in the early 1960's. I may still have a functional blue belt
Dictaphone, hand mike, and foot switch, somewhere in my mess.

As I understand it, the machine is something like this:
<http://www.videointerchange.com/images/Dictabelt3.jpg>
<http://www.gumtree.com/p/for-sale/dictaphone-timemaster-dictabelt-recorder-electronica/86424428>
<http://www.poppyrecords.co.uk/other/Dictabelts/dictabelts.htm>
<http://www.dpph.nl/content/radio_tv_audio/recorders/dictaphone/dictaphone0711.html>

If this is not the machine, it might be helpful if you would kindly
disclose some additional clues such as the maker and model numbers.

It issignificantly below 7.5 ips. I need to know the manufacturer's
specifications as I am developing a playback machine for archival work,
where comparison between the actual speed and the 'official' speed can
yield useful historical information.

Ok, I need to know the manufacturer, model number, and color of the
belt (blue or red). Please forgive me for not being able to guess
that information from your description.

To the best of my limited knowledge from 45 years ago, the nominal
speed of these devices used record speeds per the chart above. The
speed was settable and adjustable, but always followed the chart as
nominal speeds. If you have physical posession of a machine, you
should be able to measure it. If you have a clue as to the runtime of
the belt, you should be able to calculate it. The belt speed should
not have a huge effect on your playback device. If the belt contains
voice, you should be able to simply listen to the belt, and adjust the
drive speed until the speech is clear. You'll need to do that anyway
because many such dictation machines offer multiple speeds, any of
which might have been used for the recording.

Good luck.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

 

[Adrian Tuddenham]

Jeff Urban <jurb6006@gmail.com> wrote:

Interesting dilemma you got there. I searched the web but then it
would be unreasonable to think you hadn't. I found something called a
memobelt which was supposedly the same or similar.

However in thinking about it, being a scribing machine of sorts, and
given the time frame I would think two things, well one.....

It is unlikely that the unit used a capstan.

This is a belt recording system, it was driven by being tensioned around
a pair of parallel rollers.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[Adrian Tuddenham]

Jeff Liebermann <jeffl@cruzio.com> wrote:

On Thu, 29 Sep 2011 21:08:55 +0100,
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:

Jeff Liebermann <jeffl@cruzio.com> wrote:
[...]
As I understand it, the machine is something like this:
http://www.videointerchange.com/images/Dictabelt3.jpg
http://www.gumtree.com/p/for-sale/dictaphone-timemaster-dictabelt-recorder-
electronica/86424428

http://www.dpph.nl/content/radio_tv_audio/recorders/dictaphone/
dictaphone0711.html

Yes

http://www.poppyrecords.co.uk/other/Dictabelts/dictabelts.htm

This was my set-up which I am now having to replace.

[...]

Ok, I need to know the manufacturer,...

Dictaphone

model number, ...

Any Dictabelt model

and color of the
belt (blue or red).

Any belt

I am constructing a playback machine for archival work, which needs to
be able to cope with any Dictabelt. There was a standard speed which
applied to all the normal models and all belts, so as to allow
interchangeability of the belts world-wide.

The basic machine was designed for 60 c/s mains, but there were
adaptations to allow the machines to run at the correct belt speeds on
50 c/s. Some special machines were also designed to run at half speed
for logging purposes . I have already encountered some belts which were
recorded on unadapted half-speed 60 c/s machines working from 50 c/s
supplies - and, no doubt, there will be others which were recorded at
different non-standard speeds for various reasons.

What I need to know is the manufacturer's specification for the standard
belt speed which was supposed to allow interchangeability between all
the machines. I can then calibrate the speed control on my machine to
show the %age speed variation from the norm, so as to deduce information
about the circumstances under which each belt was recorded.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[Adrian Tuddenham]

isw <isw@witzend.com> wrote:

In article
1k8djs5.mfwbsv10hentqN%adrian@poppyrecords.invalid.invalid>,
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:

Jeff Liebermann <jeffl@cruzio.com> wrote:

On Thu, 29 Sep 2011 15:07:40 +0100,
adrian@poppyrecords.invalid.invalid (Adrian Tuddenham) wrote:

Does anyone happen to know the official speed of a Dictabelt?

Which maker and what model?
They followed the same speeds at record platters.
ips time
15 15 min
7 1/2 30 min
3 3/4 60 min
1 7/8 120 min

I think you have misunderstood the type of machine I am enquiring about.

[...]
It seems
to be around 6 inches per second or 30 belt revolutions per minute, but
there must be a proper specification somewhere.

30 rev/min = 0.5 rev/sec. At 12" per revolution, that's:
0.5 rev/sec * 12 in/rev = 6 in/sec.
Close enough to 7.5 ips.

It issignificantly below 7.5 ips. I need to know the manufacturer's
specifications as I am developing a playback machine for archival work,
where comparison between the actual speed and the 'official' speed can
yield useful historical information.

Any chance of there being any power-line hum in the recording? If there
is, that's your calibration. If not the fundamental, then maybe
harmonics ...

That sometimes occurs and is very helpful as long as the machine was
running from stabilised mains supplies. Some Dictabelt machines were
battery-powered and some 'in the field' would have been run from
inverters or vibrator packs.

I need to know the manufacturer's standard speed in order to measure
the variations of individual belts from the norm.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[N_Cook]

Adrian Tuddenham <adrian@poppyrecords.invalid.invalid> wrote in message
news:1k8dan9.1l7m6azx4r8h2N%adrian@poppyrecords.invalid.invalid...

N_Cook <diverse@tcp.co.uk> wrote:

Jeffrey Angus <grendelair@aim.com> wrote in message
news:j623aa$22l$1@dont-email.me...
On 9/29/2011 10:22 AM, N_Cook wrote:
Try posting to r.a.r.p ?

That would be rec.antiques,radio+phono or is
that a different group you had in mind?

Jeff

--
"Everything from Crackers to Coffins"

yep


To OP, would that use shaded pole motor and then fixed gearing?

Capacitor start/run motor with rubber idlerprimary drive; then pulleys
and a flat belt to the final drive roller shaft - so there's plenty of
slippage to give measurement errors.

Also, the machines I have seen in the UK have 60 c/s motors adapted for
50 c/s, which have very low torque and a high slip frequency on load.

(The only fixed gearing is between the drive roller and the leadscrew.)

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

For the Kennedy material someone melded the dictaphone audio to the 24? fps
of film so if any repeat noise/clicks on the belt would then be synced to
the film and a forensically accurate timing to determine the number of shots
or echoes

 

[N_Cook]

Adrian Tuddenham <adrian@poppyrecords.invalid.invalid> wrote in message
news:1k8ehbi.1k8desl4ft1duN%adrian@poppyrecords.invalid.invalid...

Jeff Urban <jurb6006@gmail.com> wrote:

Interesting dilemma you got there. I searched the web but then it
would be unreasonable to think you hadn't. I found something called a
memobelt which was supposedly the same or similar.

However in thinking about it, being a scribing machine of sorts, and
given the time frame I would think two things, well one.....

It is unlikely that the unit used a capstan.

This is a belt recording system, it was driven by being tensioned around
a pair of parallel rollers.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Patent number and then Is the original patent tech info available?

 

[Geo]

On Thu, 29 Sep 2011 21:31:54 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:

If this is not the machine, it might be helpful if you would kindly
disclose some additional clues such as the maker and model numbers.

Perhaps Adrian should have said that he has been working on these for
some time:-
e.g:-
http://cadensa.bl.uk/uhtbin/cgisirsi/x/0/0/5?searchdata1=CKEY6010012&library=ALL
http://www.poppyrecords.co.uk/other/Dictabelts/dictabelts.htm

 

[Adrian Tuddenham]

N_Cook <diverse@tcp.co.uk> wrote:

Adrian Tuddenham <adrian@poppyrecords.invalid.invalid> wrote in message
news:1k8ehbi.1k8desl4ft1duN%adrian@poppyrecords.invalid.invalid...
Jeff Urban <jurb6006@gmail.com> wrote:

Interesting dilemma you got there. I searched the web but then it
would be unreasonable to think you hadn't. I found something called a
memobelt which was supposedly the same or similar.

However in thinking about it, being a scribing machine of sorts, and
given the time frame I would think two things, well one.....

It is unlikely that the unit used a capstan.

This is a belt recording system, it was driven by being tensioned around
a pair of parallel rollers.

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk


Patent number and then Is the original patent tech info available?

Loads of patents, but I don't suppose any of them would include the
meanufacturer's designated belt speed.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

 

[Adrian Tuddenham]

N_Cook <diverse@tcp.co.uk> wrote:

Adrian Tuddenham <adrian@poppyrecords.invalid.invalid> wrote in message
news:1k8dan9.1l7m6azx4r8h2N%adrian@poppyrecords.invalid.invalid...
N_Cook <diverse@tcp.co.uk> wrote:

Jeffrey Angus <grendelair@aim.com> wrote in message
news:j623aa$22l$1@dont-email.me...
On 9/29/2011 10:22 AM, N_Cook wrote:
Try posting to r.a.r.p ?

That would be rec.antiques,radio+phono or is
that a different group you had in mind?

Jeff

--
"Everything from Crackers to Coffins"

yep


To OP, would that use shaded pole motor and then fixed gearing?

Capacitor start/run motor with rubber idlerprimary drive; then pulleys
and a flat belt to the final drive roller shaft - so there's plenty of
slippage to give measurement errors.

Also, the machines I have seen in the UK have 60 c/s motors adapted for
50 c/s, which have very low torque and a high slip frequency on load.

(The only fixed gearing is between the drive roller and the leadscrew.)

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk


For the Kennedy material someone melded the dictaphone audio to the 24? fps
of film so if any repeat noise/clicks on the belt would then be synced to
the film and a forensically accurate timing to determine the number of shots
or echoes

It is better to try to find the original specification, rather than to
deduce it from recordings which may have been altered or may not have
followed the standard in the first place.

As you can see above, it is not easy to be certain what the standard was
supposed to be, even when an actual machine is available.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk