AE Teletrainer

[DavePEI]

Findings:

I took the Teletrainer over to the museum and checked it out using my Fluke DVM - it is better than the other here, and an accurate measurement of the ring output is 24 vdc.

So I am looking for either a 24 vdc bell or a 24 vdc buzzer, possibly piezoelectric for each connected phone...

Anyone have any suggestions?

John Novack has suggested a pair of select-o-phone 30 volt bells. Anyone have a couple to spare?

Dave

[Owain]

So I am looking for either a 24 vdc bell or a 24 vdc buzzer,

(At least in the UK) buses/coaches tend to use 24V rather than 12V electrics, so a vehicle electrics supplier may be able to supply a bell for bus/coach use. Vehicle reversing beepers for commercial vehicles also tend to be 12-24V capable.

Or just use a small DC buzzer with a resistor.

(At least in the UK)  fire alarm bells/sounders usually run on 24V too.

[DavePEI]

So I am looking for either a 24 vdc bell or a 24 vdc buzzer,

(At least in the UK) buses/coaches tend to use 24V rather than 12V electrics, so a vehicle electrics supplier may be able to supply a bell for bus/coach use. Vehicle reversing beepers for commercial vehicles also tend to be 12-24V capable.

Or just use a small DC buzzer with a resistor.

(At least in the UK)  fire alarm bells/sounders usually run on 24V too.

Yes, but what I use needs to be small enough to fit inside a starlite or styleline phone Not a lot of space!

Dave

[DavePEI]

Hi All:

Ok, I have a solution to the ringer problem which will work with all phones. I have two PowerDSine 12 VDC -> 90V 20Hz AC converter modules coming from Alan Goldberg. I also have the option of using two 24 VDC converters, also by PowerDSine. Both options are shown below.

To use them, I will have to feed the ring switches from the 7812 12 volt (regulated) rather than from the bridge rectifier, to the switches, and one ring generator on each switch branch. Small modification, but it will result in a normal 90 volt 20 cycle ring to each phone connected. When a switch is depressed, it will feed 12 volts to the corresponding ring generator module. The PowerBSine modules are very similar to the Black Magic generators, and I was able to get them at a good price.

By doing this, the only changes will be moving the feed for the ring switches over to the 12 volt, and the generators have lots of room for mounting. Changing back to normal would only take a few minutes.

Thus, any phone set up for party line ringing can be used, in fact with a slight additional change, I could feed it to any unconverted phone. Too bad they didn't have these around in the 80s!

Dave

[DavePEI]

Hi Pholks:

I am looking for ideas.... My GTE Teletrainer has 1/4 inch
phone jacks for connection to the phones, Tip going to Gn
on the line cord, Ring going to YL, and the sleeve going to
Red.

Now, the problem - to make an adapter to RJ-12 to connect
any modular phone. I have temporarily soldered a cord onto
the jack, but because of the low wire count in the modular
wirem it would take almost nothing to break the thin wire -
a slight pull  would break the wire loose.

If I solder it to an 1/2 inch plug, the same problem exists
- the wire in the modular cords is too thin to resist
accidental pulls.

Has anyone got a brilliant idea to connect a modular cord
to these 1/4 inch inputs, ot a pair of modular cords with
really good wire in them which could be soldered directly
to the 1/4 inch jack and be strong enough to resist
breaking?

I wish I could find a chassis female RJ-12 type jack which
would fit in the place of the L-shaped mounts for the 1/2
inch panel jacks, but I can't think of, or find one...

Any ideas?

Dave

[Jim Stettler]

I have seen the mod cord ends that pinch crimp (w/screw) onto station cable, I have seen them on quad and cat3 4-pair.
They were used by the phone company @ some cross connect boards. I used to see them in phone rooms alot and ATT used to sell them in phone center stores.

Perhaps you can rig something w/ them.
JMO,
Jim

[AE_Collector]

Not following you Dave. The Teletrainer has 1/4" female panel mounted jacks like Phono Jacks but 3 conductor doesn't it? Do you have any old switchboard cords? A red one and a geen one with surface jacks on the the end would make an adapter cable. If using stereo headphone type jacks they have tabs inside that fold over the cable jacket to restrain it, don't they?

Terry

[DavePEI]

Not following you Dave. The Teletrainer has 1/4" female panel mounted jacks like Phono Jacks but 3 conductor doesn't it? Do you have any old switchboard cords? A red one and a geen one with surface jacks on the the end would make an adapter cable. If using stereo headphone type jacks they have tabs inside that fold over the cable jacket to restrain it, don't they?

Terry

Hi Terry:

No, the connectors are 3 conductor stereo jacks, enough conductors - the problem is coming up with a secure way to connect modern flimsy modular wires. In these, each conductor only has a few single strands - not enough to prevent breakage of the wire if the cord gets pulled.

One solution would be to use station wire connected on one end to 1/4 inch plugs to fit the jacks in the Teletrainer, with the other end terminating in a modular wall jack. But this is ugly, and not really suited to a display in the museum. It is possible that this will be the one solution I am stuck with, as it would allow me to connect to either modular or non-modular phones.

The modern stereo jacks I was able to find don't have the fold over grippers the old ones had to hold the wire in place..

I don't want to notch the Teletrainer to put modular jacks in it. There has to be a simpler way!

Dave

[HarrySmith]

Hi Dave. This may be too obvious or may not be possible but how about removing the jacks on the unit, leaving them attached but unmounted in the case and add a modular plug to the case?

[DavePEI]

Hi Dave. This may be too obvious or may not be possible but how about removing the jacks on the unit, leaving them attached but unmounted in the case and add a modular plug to the case?

In order to do that, I would have to notch the case, and I really want to leave it original if I can...

Dave

[Jim Stettler]

How about switchborad cord terminated to a surface mount modular jack.
Jim

[DavePEI]

How about switchborad cord terminated to a surface mount modular jack.
Jim

That is a possibility, Jim. It would have to be 3 conductor, though with a 3 conductor jack. I will have to check and see if I have any 3 conductor not it use.

Dave

[DavePEI]

Hi All:

I have a solution thanks to a gentleman who emailed me and suggested two Digi-Key p/n H11393-ND, a 'six-position modular jack w/ 6"harness. The harness on these is made of about #26 stranded wire, and can be soldered strongly to the 1/4 inch phone plug. Not only that, but he is sending me a couple of "samples" of the connector.

If I wish to use a normal phone with it, I can simply use a banjo connector to convert.

Funny, I was reminded tonight why I like CRPF so much! At least here, people don't question "what" you are trying to do, just help provide solutions!

Dave

[DavePEI]

I have a solution thanks to a gentleman who emailed me and suggested two Digi-Key p/n H11393-ND, a 'six-position modular jack w/ 6"harness. The harness on these is made of about #26 stranded wire, and can be soldered strongly to the 1/4 inch phone plug. Not only that, but he is sending me a couple of "samples" of the connector.

This morning's mail brought three sample Digi-Key connectors and they will work perfectly. I am going to put heat shrink tubing closest to the connector, then run them into the 1/4 inch phone jacks.

Guess what I will be doing this afternoon! By the way, high temp for today is supposed to reach 22 deg. c., , 71.6 f - yesterday reached 23 deg c., , 73.4 f. Wall to wall sunshine. Spring has finally arrived on PEI!

Dave

[Jim Stettler]

You could  also do a running knot with  lacing string along with the wires for additional stress relief
Just a thought.
Jim