UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Other Vintage Household Electrical or Electromechanical Items

Notices

Other Vintage Household Electrical or Electromechanical Items For discussions about other vintage (over 25 years old) electrical and electromechanical household items. See the sticky thread for details.

Closed Thread
 
Thread Tools
Old 7th Aug 2019, 6:00 pm   #1
Ventilate
Diode
 
Join Date: Aug 2019
Location: Serzedo, Portugal
Posts: 5
Default 16mm Valve Projector

Hello, it is my first post here so I hope I'm posting this in the right section.

I just bought a rare 16mm projector made in Canada. It is an Audio Visual Educator Model A made by Northern Tool & Gauge Ltd and the only thing I can find is this - http://progress-is-fine.blogspot.com...ountry_13.html

I haven't connected it to main. It says 110v in the main power but the motor says 220v AC/DC and the lamp 250v 1000w. I have a 110v transformer and I tried to run only the motor with it. It doesn't turn. If I run it with 220v it runs but it seems a little too fast. Maybe it's the loud noise that worries me. The motor has 6 wires and two of them were disconnected when I got it.

As for the audio, it has optical sound and six valves. One is broken at the bottom and one has a loose glass piece inside. One of the valves doesn't have markings, hope you can help me on that one.

As for the capacitors, some of the small ones seem to be leaking so I will replace them. I tried to test the big ones with the multimeter( resistance mode- value going to infinity) and they seem good.

There is also a strange valve with a wire on top that connects to the photosensor. It is on the right in the pictures.

Hope we can get in running
Attached Thumbnails
Click image for larger version

Name:	1-Educator.jpg
Views:	239
Size:	148.7 KB
ID:	188005   Click image for larger version

Name:	2-right side.jpg
Views:	205
Size:	136.3 KB
ID:	188006   Click image for larger version

Name:	3-left side.jpg
Views:	201
Size:	161.6 KB
ID:	188007   Click image for larger version

Name:	4-valves.jpg
Views:	222
Size:	152.8 KB
ID:	188008  
Ventilate is offline  
Old 7th Aug 2019, 11:40 pm   #2
Graham G3ZVT
Dekatron
 
Graham G3ZVT's Avatar
 
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,675
Default Re: 16mm Valve Projector

I found this in Google's Web cache
https://webcache.googleusercontent.c...&ct=clnk&gl=uk

It was in this period that film production and distribution companies such as
'social guidance' pioneer, Coronet Films (formed 1946) began to make their appearance.With schools and teachers on board, educational films became a lucrative commercial market and advertisers targeted them successfully. "The Audio Visual Educator, [a 16mm projector] as it was known, retailed at $585 in 1946 (roughly $7,100 today) but it was available to tax exempt organizations for $430 ($5,200) ...it was actively promoted, and demand was known to exceed supply. By 1948, for instance, the principal distribution outlet in Montreal was a full six months behind in supplying new machines to customers." (Lester 2008, p.250)


And from:
http://citeseerx.ist.psu.edu/viewdoc...=rep1&type=pdf
Also noticeable in Canada within the first year of war's end was the renewed
emphasis on the actual manufacturing of 16mm projectors. The Ottawa-based
Northern Tool & Gauge Co. Ltd., for instance, from February to September 1946,
manufactured about one thousand 16mm projectors, about half of which were sold to
schools, churches and hospitals throughout the country, with the remainder exported
to South American and European countries, such as Argentina and Portugal, with
additional distributors established in Africa and China. The portable projector came
in an aluminum case, was approved by the Canadian Standards Association and life
tests proved its durability for over 3,000 hours. The Audio Visual Educator, as it was
known, retailed at $585 in 1946 (roughly $7,100 today) but was available to tax exempt
organizations for $430 ($5,200). It was the only noteworthy 16mm projector
manufactured in Canada at the time and was actively promoted, and demand was
known to exceed supply. By 1948, for instance, the principal distribution outlet in
Montreal was a full six months behind in supplying new machines to customers. By
that year it was estimated that 6,000 16mm projectors were in use in Canada, many of
which were the product of Northern Tool & Gauge Co.
__________________
--
Graham.
G3ZVT
Graham G3ZVT is offline  
Old 8th Aug 2019, 12:58 am   #3
Ventilate
Diode
 
Join Date: Aug 2019
Location: Serzedo, Portugal
Posts: 5
Default Re: 16mm Valve Projector

Thank you, that is so cool to know!

So I should assume, since it was exported, that it is a 220v device but they didn't have the right label in the factory? Or it is a dual voltage device and part of the label is missing, which it is?
Ventilate is offline  
Old 8th Aug 2019, 2:21 am   #4
Techman
Dekatron
 
Techman's Avatar
 
Join Date: Nov 2009
Location: Lincolnshire, UK.
Posts: 4,985
Default Re: 16mm Valve Projector

I'm not familiar with your model at all, but I have, and use, a B & H model dating from around 1942 and it runs on 110 volts via a large transformer.

The optical sensor in these is usually a device that looks like a valve with a 4 pin base and MUST be kept in the dark as it's a bit like the old photographic printing paper that's ruined if exposed to light.

The two valves that appear to be broken may well still work fine.

There may well be some very high value resistors around the optical sensor which will have gone even higher in value, and also paper capacitors that have leakage that will drag down the voltage in this very high impedance circuit.

It looks like you've got your work cut out with this one.
Techman is offline  
Old 8th Aug 2019, 9:35 am   #5
Lucien Nunes
Rest in Peace
 
Join Date: Apr 2008
Location: London, UK.
Posts: 2,508
Default Re: 16mm Valve Projector

If the motor has brushes and a commutor then its speed will probably be regulated by two centrifugal governors within, one each for sound and silent. If it has a reverse swtch then the field and armature wires need to be brought out separately to that, which explains the number of wires on the motor. E.g. 16fps gov, 24fps gov, gov common + field, field end, 2x armature. When testing, if you bypassed the governor, the motor would have run significantly too fast. I would expect it at least to turn, although too slowly, on 110V, so the mechanism may be stiff.

110V projection lamps were more efficient and longer lasting than 230V on account of the shorter, thicker tungsten filament. Projectors made in, or exported to, 220/230/240V countries often therefore used 110V lamps, with either a 110V or 230V motor and amplifier. The means for reducing the 230V to the lamp voltage was usually external to the projector, either a transformer or in the early days optionally a large resistor if the projector was to be used on a DC supply. Bell and Howell projectors, for example, had a 4-pin input connector with separate feeds for the motor / amplifier and lamp, from the transformer, although both were usually at 110V unless for whatever reason a 230V lamp was fitted. In the absence of a service manual, you will have to investigate the supply configuration in your unit.
Lucien Nunes is offline  
Old 8th Aug 2019, 1:25 pm   #6
Ventilate
Diode
 
Join Date: Aug 2019
Location: Serzedo, Portugal
Posts: 5
Default Re: 16mm Valve Projector

In this projector, if I'm not mistaken, the power runs straight to the motor and lamp. The lamp can only be turned on if the motor is running. There seems to be no reverse button.

It may indeed be stiff as it makes some rather unpleasant noises when running. I've lubricated what I can but maybe it needs a full mechanical service. Visually it looks very nice.

I think I'm going to put it all together and just connect it to 220v. The guy that I bought it from tried it on 220 and the ON lamp is still good
Ventilate is offline  
Old 15th Aug 2019, 2:34 pm   #7
Ventilate
Diode
 
Join Date: Aug 2019
Location: Serzedo, Portugal
Posts: 5
Default Re: 16mm Valve Projector

I connected it to 220 and everything seems fine. Only two of the valves got hot though. I will check the capacitors for the other ones. If they don't get hot should I assume they are broken?
Ventilate is offline  
Old 15th Aug 2019, 5:30 pm   #8
PJL
Dekatron
 
Join Date: Sep 2005
Location: Seaford, East Sussex, UK.
Posts: 5,997
Default Re: 16mm Valve Projector

I have a 1946 Ampro I restored but that was imported to the UK so is 110-120V. The sound detection has two components, a lamp that is modulated by one of the 6V6 and a photo detector that looks like a small valve.

These projectors get very hot so you need to use a high temperature lubricant that does not evaporate quickly and the motor/fan must be running smoothly. Because of the excessive heat, I would recommend replacing all paper and electrolytic capacitors and checking the value of the resistors.
PJL is offline  
Old 15th Aug 2019, 11:01 pm   #9
Ventilate
Diode
 
Join Date: Aug 2019
Location: Serzedo, Portugal
Posts: 5
Default Re: 16mm Valve Projector

Modulated in what sense? Doesn't it need to be at a constant brightness? There is only a small screw near the detector that I assume is for sensitivity?

I used engine oil that I have for motorcycle gearboxs, should be enough.

Is there a way to test the valves to know for sure if they are good? I believe they are not the original ones.
Ventilate is offline  
Old 15th Aug 2019, 11:02 pm   #10
matthewhouse
Octode
 
matthewhouse's Avatar
 
Join Date: Jul 2006
Location: Willand, Devon, UK.
Posts: 1,023
Default Re: 16mm Valve Projector

Quote:
Originally Posted by Ventilate View Post
If they don't get hot should I assume they are broken?
No don't assume, or things will start getting expensive buying parts that are not needed. Checking to see if the heaters are glowing is a good place to start, if they are glowing there is a good chance the valve is ok, if not checking to see if the valves heater pins have power is the next step.

Remember the lower power valves don't get anywhere near as hot as the higher power output and rectifier valves.

Do not force any mechanical part that seems stuck, instead, dismantle the parts and clean them. Smaller parts are easy to damage. Old grease can turn very hard like wax and jam things.
matthewhouse is offline  
Old 16th Aug 2019, 10:12 am   #11
Herald1360
Dekatron
 
Herald1360's Avatar
 
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,526
Default Re: 16mm Valve Projector

Quote:
Originally Posted by Ventilate View Post
Modulated in what sense? Doesn't it need to be at a constant brightness? There is only a small screw near the detector that I assume is for sensitivity?

I used engine oil that I have for motorcycle gearboxs, should be enough.

Is there a way to test the valves to know for sure if they are good? I believe they are not the original ones.
The sound lamp needs to have a stable, noise free low voltage supply to provide the constant brightness it does need to have. The obvious one, dc, was actually rather difficult to obtain from mains driven circuitry in the valve era. One way round this was to use high frequency (above audible) ac instead. The watt or so needed was well within the capability of a typical audio output valve (eg 6V6) used as an oscillator. Thermal inertia in the filament was more than adequate to clean up the HF ripple which might otherwise have upset the sound amplifier albeit inaudibly.
__________________
....__________
....|____||__|__\_____
.=.| _---\__|__|_---_|.
.........O..Chris....O
Herald1360 is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 11:34 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.