Bell & Howell Audio Cable Format- Smaller than 1/4"?

[nathan130]

I've got a Bell & Howell 16mm Filmosound Projector that looks pretty much identical to the model in this film:

http://www.youtube.com/watch?v=Vekdqqgu ... 57&index=3

The cable that goes from the amp to the speaker box is quite old and broken in spots, resulting in really poor sound. The cable is slightly smaller than a 1/4" though. I've gone to some electronic places and also shown it to some audio guys- They don't know what the format is called-
Anyone have any solutions?
I'd prefer to buy a new cable over pulling the projector apart and modifying it to take 1/4". I'm not that handy with a soldering iron.
Hope someone can help. Thanks!

[Blue Audio Visual]

Could it be a Bantam jack?

They look very much like 1/4", but are a bit smaller.

I don't think you will be able to buy a Bantam speaker lead over the counter, but it would be easy to buy 2 Bantam jacks and some suitable speaker cable.

You also get a type often referred to (at least here in the UK) as a GPO jack, but they are a tiny bit bigger than 'normal' 1/4" jacks.

[nathan130]

Thanks for the response!
Very highly possible it's a bantam jack. I'm not sure the exact measurement size of a bantam cable, but looking at pictures online it looks highly plausible, if it is as you say, slightly smaller than 1/4".

Both my amp and speaker box have the jacks in them, so I wouldn't need any frayed speaker cable wiring to wrap around the speaker box, if that's what you mean by speaker lead?

Thanks for the help- I'll probably try bringing my cable into an audio equipment shop and asking if they can order me in a bantam cable incase it doesn't fit and I need to return it.

[Blue Audio Visual]

A Bantam jack is nominally 4.4mm diameter, compared to a 'normal' 1/4" jack which is 6.35mm

You'll need to go to a pro-audio supplier, not a HiFi shop, assuming that it is actually a Bantam jack that you need.

As to "speaker cable", I mean the wire within the lead itself. Speaker and audio signal leads are different internally, even though they may look the same on the outside. Speaker cable will typically be made out of 2 evenly sized cores laid side by side. That's not to say that an audio cable won't work, but it isn't the right way of going about it.

The likelihood of finding a pre-wired mono Bantam speaker cable is something near zero, so like it or not you may need to get the soldering iron out...

*all assuming it is actually a Bantam connector in the first place*

If it was me, I'd consider reusing the 2 connectors on the existing lead, and getting someone to solder a new length of suitable speaker cable between them, because then exactly which type of connectors they are becomes a moot point as you won't need to buy any replacements anyway. It would be pretty unusual for the jack itself to have become faulty (but not 100% unknown), although the same is not necessarily true of the sockets that they fit into in the projector and speaker, which are likely to have suffered more mechanical stress over the years.

First thing to do is to conclusively identify if the cable is faulty or not, that should be easy to do using the continuity function on a multimeter whilst wiggling and shaking the lead a bit.

[David M. Leugers]

I suspect that the old B+H speaker jack is the same as used on the Kodak Pageant 16mm projectors. There are tons of them around with problems not worth fixing as they are very labor intensive to repair. Maybe you could just buy the external speaker which is part of the case that comes off to use the projector. It has a long extension cord with the right plug attached to it. Just make sure it has the smaller plug and has not been modified for the more standard 1/4" plug...

[nathan130]

I ordered a bantam jack and it wasn't the right size- too small.

[littlesongs]

It is not unusual for gear from the 1940s to use mil-spec components. My best guess is that your projector was originally designed on a war contract. The cable may have standard PL-68 connectors or something like the Post Office 316 / B-gauge plug.

If it was me, I'd consider reusing the 2 connectors on the existing lead, and getting someone to solder a new length of suitable speaker cable between them, because then exactly which type of connectors they are becomes a moot point as you won't need to buy any replacements anyway. It would be pretty unusual for the jack itself to have become faulty (but not 100% unknown), although the same is not necessarily true of the sockets that they fit into in the projector and speaker, which are likely to have suffered more mechanical stress over the years.

I agree that this is your best bet. It would only take a couple of minutes to solder new cable to the original connectors. If the idea of DIY is too much, any place that does electronics repair, a pro audio store, or a mom-n-pop guitar shop with an amp tech could do it on the cheap. As a last resort, grab a six pack of good beer, troll the street for antennas, and make an offer of barter with your friendly neighborhood Ham.

[digicube]

It's a 3/16" phone plug. It's discussed in this thread. http://www.8mmforumworldwide.com/viewtopic.php?t=1570
The closest adapter I've found is this. https://heilsound.com/products/ad-1-c-r ... lins-plug/
I've purchased it but it's not working well. The base is too wide and the jack on my Kodak Pageant is recessed so the plug won't snap into place. I manage to hear sound at the highest audio level by using an amplifier but it was very bad quality and lots of noise. Maybe it's because the 3/16" plug is a stereo one or that it can't snap into place that's causing it. Right now I'm looking for a 3/16" mono plug so I can solder it to the Heil Sound AD1C adapter.