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Posted By: TeletypeJoe 760A Loudspeaker - 04/04/11 03:23 PM
Hi,

What was the 760A loudspeaker used for?

I just scored one for 9 bucks on e-pay that some nincompoop had screwed a four prong plug onto its side. I am going to remove the plug and attempt to fill the holes with chemically melted ground up plastic from a the shattered shell of a green 500. I will first try acetone, and if that does not work, I will try using hot toluene. Failing that, I might (in a high flow fume hood in a chemistry research lab) try using ether in a steam tank... that should melt any plastic. I will see if this works, and if it is at all successful, I will post pics about it.

Joe

PS I just got a line on a Klienschmidt reperf! In negotiations for it right now. More to come.
Posted By: EV607797 Re: 760A Loudspeaker - 04/04/11 06:38 PM
It is just a basic amplified speaker that will deliver whatever you send to it via the tip/ring pair to allow others in the room to hear both sides of the conversation. They can't talk back, though. They offered many purposes, but the most common was to just connect the tip/ring to the handset receiver terminals inside of a phone.

The black/yellow pair requires 13.6VAC to power the amplifier.
Posted By: TeletypeJoe Re: 760A Loudspeaker - 04/06/11 11:18 PM
Well, my 760A speaker has arrived. Some of you might have seen it on e-pay. It was (is) filthy. The good news is that the butchery done to it was a lot less obnoxious than I thought that it would be. Before I go on, here is the silly thing before I did anything to it.

[Linked Image from i83.photobucket.com]

[Linked Image from i83.photobucket.com]

[Linked Image from i83.photobucket.com]

[Linked Image from i83.photobucket.com]

It was not obvious on the e-pay description that there was a stub of the original wire left. I had wrongly assumed that there had been a hole drilled underneath the four prong plug that had been screwed onto the side of the unit to pass the connecting wires through. Thankfully I was wrong, and there were only two very small little holes where the sheet metal screws had been driven through the plastic. Unfortunately, the force on the plastic from said sheet metal screws has deformed the plastic somewhat.

Any way, here is an image of the unit after I removed the plug.

[Linked Image from i83.photobucket.com]

[Linked Image from i83.photobucket.com]

Notice the discoloration of the plastic shell. I am guessing that this is due to very long term exposure to either sunlight or flourescent light as well as environmental grundge (in this case, I believe it was a mix of smoke and auto shop grease.

After this, I took the shell off of the unit. It seems that this unit was either orignially not an amplified unit, or that at some time in its life, someone removed the amplifier. There are two extra tiny threaded screw holes in the base of the unit where a printed circuit card could have been mounted. However, the green wire stub that is attached to the speaker only has two wires in it... red and green. This makes me think that this was originally built or installed as a passive speaker with the amplification done in another piece of equipment.

Here are a couple of shots of the inside of the unit.

[Linked Image from i83.photobucket.com]

[Linked Image from i83.photobucket.com]

Since the screw holes are so small, rather than making a chemically soften mush of green plastic to attempt to fill the holes, I took tiny shards of green plastic from the shattered shell of an old 500 set and carefully jammed into the screw holes. I stuffed as much into the holes as I could using a pair of tweezers. Then I liberally applied drops of cyanoacrylic glue to the holes and shards in an attempt to weld the shards to the plastic shell. This technique worked in the past for me when I repaired a cracked keyset shell. I am letting the speaker shell sit over night to let the glue and plastic harden, then I will if necessary, take some green plastic dust, mix with more cyanoacrylic and cover any little voids that might be left.

Then I will start the restoration of the shell with a vigourous cleaning via the dishwasher, then the usual sanding/polishing process. (the unit is deeply scratched.)

I will have more photos tomorrow evening. In the mean time, does anyone know where I might find a green two wire cable for this thing?

Also, can anyone tell me if the aluminum grile is supposed to be a matt finish or is it supposed to be shiny?

Thanks again!

Joe
Posted By: Lightning horse Re: 760A Loudspeaker - 04/07/11 06:55 AM
Joe, this may actually be a talkback speaker for an intercom. Measure the DC resistance of the speaker coil. 4-16 ohms probably no. 40-50 ohms probably yes.
Posted By: Arthur P. Bloom Re: 760A Loudspeaker - 04/07/11 08:36 AM
It is the speaker part of a 3A or 3B speakerphone set. It is not a Spokesman® or the ITT clone, the Orator®.

The Spokesman (model 107A or B) has an amplifier inside and a 4- or 6-conductor cord. It has a volume control on the front faceplate.

ITT also made a two-way talk-back system that used a similar-looking item, the Call Announcer®. It used the same form factor but had an additional switch on the roof, and an LED busy lamp.

Call Announcer

It homed in on a special dial-selective intercom unit in the 76A KSU.

The faceplate is matte finish. A CORD (not cable) in -51 can be located easily. You can use one that has more than 2 conductors, of course. Now you need to find the 666 transmitter and the 55B control unit. Good Luck!
Posted By: Lightning horse Re: 760A Loudspeaker - 04/07/11 04:57 PM
Arthur, you didn't waste that hold time staring off into space. You cheated and read the manuals! smile
Posted By: TeletypeJoe Re: 760A Loudspeaker - 04/07/11 09:35 PM
@ Lightninghorse,

I did measure the resistance across the little speaker and it was right around 20 Ohms. I could hear the speaker crackle a little bit when I touched the probes to the speaker terminals.

As far as the shell, surgery went well last night. Here is a photo of the unit the next day after stuffing the holes and welding with cyanoacrylic glue.

[Linked Image from i83.photobucket.com]

After hardening over night, this evening, I started to smooth out the holes. Don't laugh, but I used a diamond nail file. Yes, one of those cheap give-a-ways that are given as part of 'gift packages' to women when they attend conferences.

[Linked Image from i83.photobucket.com]

No, I am not a woman who goes to conferences, but my wife is, and she has dozens of those things. I snagged a couple, and put in my 'phone shell restoration box'. They are really perfect for this use, as the carrier metal is aluminium, and thus are quite flexible. Swiss needle files and diamond files are not nearly so flexible, so a lot of damage can be done to the surrounding plastic.

Here is a shot of the unit after I smoothed down the filled holes.

[Linked Image from i83.photobucket.com]

The plastic was not quite fully hardened yet, so I took the shell and placed it in a box along with a small saucer of water and placed that on top of my TTY powersupply that I turned on. (Cyanoacrylic has to have humidity to activate and cure. The TTY powersupply gets nice and (as I call it) "kitty sleeping" warm. (The resident felines love to nap on top of it when it is turned on.)

Tomorrow, if the plastic is fully hardened, it will be baptized by dishwasher, and I will then start the polishing process. (I do use the dishwasher quite a lot in my phone endeavors, so I am thinking about installing one in my future 'phone barn' this summer.

More to come!

Joe
Posted By: Silversam Re: 760A Loudspeaker - 04/08/11 02:11 PM
Joe-

The 760 is the speaker part of the WECO 3 series speakerphone. There's nothing else that went in that box, just the speaker. I don't know what you'd use it for without the rest of the unit.

Sam
Posted By: TeletypeJoe Re: 760A Loudspeaker - 04/08/11 09:06 PM
Hi Sam,

I was really just testing some ideas that I had on repairing plastic shells. I picked it up for a sawbuck thinking that if I screw it up, it would be no great loss.

As Arthur noted, I am looking around for the rest of the set, but I suspect that once this little project is finished, that the unit will sit on a display shelf with other green phones. The WECO series three components are hard to come by.

One last question (well two actually)...

Was there originally a cork bottom on the unit, and if so, would it be considered cheating to cut out a new bottom from some cork gasket material? Second, Arthur referred to "...a cord in -51..." Does the -51 denote the color?

Thanks as always,

Joe
Posted By: TeletypeJoe Re: 760A Loudspeaker - 04/17/11 03:14 AM
Update on the 760A shell...

I have finally completed the polishing of this thing. I wound up spending more time on it than any nasty old 500 shell that I have cleaned up. I have never seen a piece of plastic so discolored so deeply, and so beat up as well.

Took over eight hours of careful hand sanding (in order not to round the edges or destroy the 'Western Electric' logo.

But, after careful sanding and hand polishing, it is nice and shiny. The two holes that had been where the socket had been 'attached' are smooth and glossy as well, but there is just a bit of color difference between the shell and the patches. Its not perfect, (nor am I :rolleyes: ), but I am quite happy with the outcome. Tomorrow after work, I will clean the metal base, reattach the speaker to said base and re-assemble the unit (sans cord until I can find one).

I will post photos either tomorrow or monday.

Joe
Posted By: Arthur P. Bloom Re: 760A Loudspeaker - 04/17/11 07:54 AM
Quote
Does the -51 denote the color?
WESTERN ELECTRIC COLOR SUFFIX LIST

CODE DESCRIPTION APPLICATION BSP REFERENCE

- GRAY, beige 200-KTU cabinet C53.152
- GRAY, french 205 hand tel set 548-500-410
- IVORY 205 hand tel set 548-500-410
3 BLACK tel sets
4 IVORY tel sets, wiring, cords C36.101 (B) NY
5 GRAY
6 BRASS, old 205 hand tel set 548-500-110
7 BRONZE, statuary 205 hand tel set 548-500-110
8 SILVER, oxidized 205 hand tel set 548-500-110
9 BROWN wiring
10 (BROWN) ?
11 GOLD medium 202 tel set catalogue #9
12 GOLD dark 302 tel set C36.101 (B) NY
13
14
15
16 ROSE, old 302 tel set C36.101 (B) NY
17 pending
18 BLUE, dark 302 tel set C36.101 (B) NY
19 GREEN, gray 302 tel set C36.101 (B) NY
20 RED, pekin 302 tel set C36.101 (B) NY
21 pending
22
23
24
25
26 GREEN, olive 50-type KTU’S C53.152
27 WALNUT 50-type KTU’S C53.152
28
29 TRANSPARENT
30
31
32
33
34
35
36
37
38
39
40 GREEN, grey wrinkle
41
42 BEIGE, rose wiring
43 BEIGE 608 PBX
44 CHROME 1-type coin tel set 506-410-400
45 GREEN, grey textured vinyl
46
47
48
49 GRAY, light olive wiring, misc eq
50 IVORY 500 tel set supply catalogue
50A 2-tone IVORY
51 GREEN, moss 500 tel set “
51A 2-tone GREEN
52 GRAY, oxford 500 tel set “
52A 2-tone GRAY
52 *** IVORY, electrical Suttle Products., Inc. online catalogue ***
53 RED, cherry 500 tel set C18.051.00
53A 2-tone RED
54 BROWN, mahogany tel sets supply catalogue
55 BEIGE, dark tel sets “
56 YELLOW ,pastel tel sets “
57 BLUE, teal tel sets “ (mediterranean)
58 WHITE tel sets “
59 PINK, rose tel sets “
60 BEIGE, light tel sets “
61 GRAY tel sets “
62 BLUE, aqua tel sets “
63 GOLD bell chime C18.051.00
64 TURQUOISE tel sets
65 GRAY, dark 178A backboard 500-120-100 Issue 5 April 1965
66
67 STEEL, stainless, brushed coin tel sets 506-410-400
68
69 RED, muted 1500/2500 series faceplates 502-515-121
70 CHARCOAL “
71 GREEN, light “
72 YELLOW, light “
73 GRAY, light “
74 PINK, muted “
75 BEIGE, muted “
76 BLUE, muted “
77 TURQUOISE, muted “
78 SILVER Paper faceplate insert Call Director 502-601-101
79 GOLD “ ” “
80 IVORY, muted “
81
82 PEARL-GRAY, neutral light 830-series tel set cords. 503-702-101
83 GRAY-BROWN, dark “ ”
84 BRONZE coin tel sets 506-410-400
85
86 ORANGE coin tel set (part)
87 SATIN-SILVER cords
88
89
90
91
92
93 YELLOW sculptura tel set

100 AVOCADO COM KEY 416 faceplate
104 BROWN, chocolate trimline tel set
105 GREEN, dark “
108 TEAK COM KEY 416 / Touch-a-matic faceplate
109 WALNUT “ ” ”
111 GOLD, harvest “ and trimline tel set
112 ORANGE COM KEY 416 faceplate
113 BROWN, textured “
114 RED, bright “ and trimline tel set
115 BLUE, royal “
118 BLACK, textured “
122 ALUMINUM, matte Touch-a-matic 32 faceplate 503-603-101
123 YELLOW, butter noteworthy tel set
124 RUST trimline tel set
139 GRAY, charcoal “
142 BLUE, midnight “
143 BURGUNDY “
144 CINNIBAR “
145 BLUE, teal “
146 TEABERRY, dark “
147 APRICOT, creamy “
170 MOCHA “


215 CREAM, misty Spirit Key Tel
226 GREEN Jacks
235 ASH, light
245 BROWN, electrical
246 IVORY, electrical
262 WHITE Systemax (jacks)
264 WHITE, oxford or AT&T
270 GRAY
Posted By: jeffmoss26 Re: 760A Loudspeaker - 04/17/11 09:43 AM
What a great list! Thanks Arthur!
Posted By: TeletypeJoe Re: 760A Loudspeaker - 04/18/11 03:42 PM
Me too! Thank you Arthur, this is indeed a good bit of information for me.

I will post photos tonight of the finished speaker.

Joe
Posted By: John Osvatic Re: 760A Loudspeaker - 04/19/11 07:34 AM
Joe, If all the parts came 100% then you wouldn't have anything to do but the "Honey Do" list!
Posted By: TeletypeJoe Re: 760A Loudspeaker - 04/23/11 09:55 PM
Well, here is the promised update!

First, here is the inanimate star of this thread...

[Linked Image from i83.photobucket.com]

Much cleaner and shiny-er now.

Another view...

[Linked Image from i83.photobucket.com]

Here we see the patched holes. Almost the same color, but not quite. One really has to look for them, but they are there. This way, I know it is mine.

OK, here is the newest addition to our household. He is five weeks old, and already a phone nut. His name is Rokumon, and has bonded with me very tightly. Where ever I am, so is Rokumon. Here he is talking to his mother...

[Linked Image from i83.photobucket.com]

I will have more photos of him in the phonebooth forum!

Best,

Joe
Posted By: Arthur P. Bloom Re: 760A Loudspeaker - 04/24/11 08:13 AM
Reminds me of this:


[Linked Image from cache2.allpostersimages.com]
Posted By: TeletypeJoe Re: 760A Loudspeaker - 04/24/11 12:50 PM
Yep, a feline version of that!
Posted By: Arthur P. Bloom Re: 760A Loudspeaker - 04/24/11 04:48 PM
Puma T. Cat and his pink Spokesman®

[Linked Image from i257.photobucket.com]
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