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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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20th Feb 2020, 1:17 pm | #1 |
Octode
Join Date: Dec 2006
Location: Colchester, Essex, UK.
Posts: 1,076
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Bell & Howell Gaumont Loud Speaker
Can anyone tell me what make of speaker this is. Rola Celestion maybe ?
Could this be of any value, either for the speaker or for complete cabinet for a home movie equipment collector ? Mike. |
20th Feb 2020, 1:29 pm | #2 |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,198
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Re: Bell & Howell Gaumont Loud Speaker
Many of the Bell & Howell speakers of this vintage were made by Jensen in the USA, but the 'Made in England" label suggests otherwise.
I believe that Goodmans did make drivers for some US brands, as suggested in https://www.lencoheaven.net/forum/in...?topic=18530.0 . This may be one of them. Martin
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20th Feb 2020, 1:50 pm | #3 |
Octode
Join Date: Dec 2006
Location: Colchester, Essex, UK.
Posts: 1,076
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Re: Bell & Howell Gaumont Loud Speaker
I did wonder if they were Tannoy, due to the frame resemblance.
Mike. |
21st Feb 2020, 6:55 pm | #4 |
Hexode
Join Date: Mar 2008
Location: Bristol, UK.
Posts: 388
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Re: Bell & Howell Gaumont Loud Speaker
I recently sold one,looked identical,3ohms,Goodmans,from a vintage gram. A nice speaker.Les
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22nd Feb 2020, 10:14 pm | #5 |
Dekatron
Join Date: Nov 2009
Location: Lincolnshire, UK.
Posts: 5,000
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Re: Bell & Howell Gaumont Loud Speaker
Those speakers are normally what's known as 'mains energised', in other words they don't have a permanent magnet, but an electromagnet. They're not actually energised by the mains, but by being part of the HT supply for the amplifier in the form of a choke. There's normally a four core speaker cable, two for the audio and two for the HT. A projector manufacturer would never fit a crude cable through a hole drilled in the side of the cabinet with a knot as a cord grip, so I think that speaker is not original and has been replaced by the permanent magnet example that you have. You're actually very lucky, as the large mains (HT) energised type are virtually worthless, but the one you have is reasonably desirable by comparison - certainly a lot more useful.
Edit: I'll revise my statement regarding originality, as I now notice that the speaker has GB equipments on it, which would make it original to a projector, being the suppliers of such, with a built in choke in the amplifier, but the way the cable is fitted is rather suspicious all the same. Last edited by Techman; 22nd Feb 2020 at 10:20 pm. |
22nd Feb 2020, 10:57 pm | #6 |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
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Re: Bell & Howell Gaumont Loud Speaker
I’ve not yet come across a ‘mains energised’ speaker with a Bell & Howell 16mm projector, though I believe that, in common with pre-war radios, some pre-war cinema sound installations used ‘mains energised’ rather than permanent magnet speakers.
Martin
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22nd Feb 2020, 11:33 pm | #7 |
Dekatron
Join Date: Nov 2009
Location: Lincolnshire, UK.
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Re: Bell & Howell Gaumont Loud Speaker
Interesting you should say that. I've got two, one dating from the early 1940s and one dating from the mid 1960s and they both have mains energised speakers in their cabinets. Also, when I used to do evening projection work for various organizations in the 70s, I came across and used quite a few of these projectors and they all had the energised speakers, so a standard speaker in one of these cabinets is very unusual to me, although I seem to remember reading somewhere that some were made with standard speakers. The later models that had a small built in monitor type speaker used a standard speaker for this, but an energised type for the main extension cabinet.
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23rd Feb 2020, 9:09 am | #8 |
Octode
Join Date: Dec 2006
Location: Colchester, Essex, UK.
Posts: 1,076
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Re: Bell & Howell Gaumont Loud Speaker
I did realise that the mains cable outlet was done by a previous owner and was not original. I guess the cables were normally stowed in the rear compartment, so holes in the cabinet were not needed? Possibly signs of a cable restraint strap inside, I will look.
Mike. |
23rd Feb 2020, 9:33 am | #9 |
Octode
Join Date: May 2009
Location: Stevenage, Herts. UK.
Posts: 1,518
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Re: Bell & Howell Gaumont Loud Speaker
It's not an energised speaker, but a normal 16ohm permanent magnet type. The badge tells you it was made to go with the 601 projector. The 601 was the first Bell & Howell USA design built under licence by Rank (Gaumont British) in their factory in Mitcheldean Gloucestershire. Introduced early 1948. For really large halls the plug and socket system allowed you to parallel two speakers and the projector amplifier had both 8 & 16 ohm outputs to suit.
It replaced the previous GB-L516 model which was a prewar British design and did have an energised speaker connected to the projector by a four core cable. My 516 is fitted with a Goodman's speaker so it's quite possible they also supplied the later unit. In time the 601 was followed by the 621, 631 and 640 series of projectors, the latter being the last to be built in the UK in the early sixties. Subsequent production moved to Japan. None of these machines used energised speakers. Last edited by wd40addict; 23rd Feb 2020 at 9:43 am. |
23rd Feb 2020, 9:39 am | #10 |
Dekatron
Join Date: Jun 2013
Location: East Sussex, UK.
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Re: Bell & Howell Gaumont Loud Speaker
Looks as though one of the cables/solder tags had come adrift. Should be easy to repair.
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23rd Feb 2020, 10:57 am | #11 |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
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Re: Bell & Howell Gaumont Loud Speaker
I have a distant memory of the projector at primary school c1950, probably a B&H. I recall peeking into the half-open speaker unit and imagining I saw some electronics. Could that have been so? Did the mains energised speaker ever include the power amplifier in the same cabinet?
Martin
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23rd Feb 2020, 11:21 am | #12 |
Octode
Join Date: May 2009
Location: Stevenage, Herts. UK.
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Re: Bell & Howell Gaumont Loud Speaker
The L516 speaker included two large inductors and two capacitors. One inductor is for HT smoothing and the other for a crude 100Hz filter to reduce mains hum. Possibly earlier units had energised speakers and in later units PM drivers.
Just to confuse you further another accessory was the powered speaker for use with the 601 and later. This contained a pair of 6V6s driven by a phase splitting transformer fed from the LS output of the projector's own amplifier. This would give another 15W or so for really big rooms. |
23rd Feb 2020, 11:23 am | #13 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,861
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Re: Bell & Howell Gaumont Loud Speaker
Looks Goodmans to me
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24th Feb 2020, 9:52 am | #14 |
Hexode
Join Date: Mar 2008
Location: Bristol, UK.
Posts: 388
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Re: Bell & Howell Gaumont Loud Speaker
It looks like the original mains-energized arrangement has been replaced with the Goodmans job. My speaker was identical apart from the coil connection,mine had a paxolin strip mounted on the rectangular projection to the right of the knotted cable. Les
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24th Feb 2020, 1:29 pm | #15 |
Octode
Join Date: May 2009
Location: Stevenage, Herts. UK.
Posts: 1,518
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Re: Bell & Howell Gaumont Loud Speaker
The cabinet comes from a 601, the 601 never had an energised speaker!
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