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Vintage Telephony and Telecomms Vintage Telephones, Telephony and Telecomms Equipment |
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11th Jan 2017, 12:40 am | #1 |
Heptode
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BT Robin - Answering Machine 202A
Does anyone know what voltage the Plug Top power supply for the BT Robin (Machine ,Answering & Recording No 202A) http://www.britishtelephones.com/ansr202a.htm, introduced in 1985, used?
I've just found one at home (as you do!) but no PSU As usual with a lot of BT equipment, there is no mention on any labels on it, of the required voltage. |
11th Jan 2017, 8:42 am | #2 |
Dekatron
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Re: BT Robin - Answering Machine 202A
I'll check to see whether the one in my store room has its PSU.
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11th Jan 2017, 10:00 am | #3 |
Dekatron
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Re: BT Robin - Answering Machine 202A
This seems to be a common query: https://www.vintage-radio.net/forum/...d.php?p=737483
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11th Jan 2017, 8:10 pm | #4 |
Dekatron
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Re: BT Robin - Answering Machine 202A
And unfortunately, I am unable to assist as my Robin has no power supply either. More importantly, not only is there no indication of voltage but also what the polarity is of the connector - though the latter can presumably be established by dismantling and looking at the circuitry (which I haven't done).
edit: I see that the point about polarity is also discussed in the referenced thread. Perhaps I should have looked there before replying.
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12th Jan 2017, 11:09 am | #5 |
Dekatron
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Re: BT Robin - Answering Machine 202A
I remember or think mine was 18Volts.
PS The worst thing on these is dry joints in abundance
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12th Jan 2017, 12:28 pm | #6 |
Heptode
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Re: BT Robin - Answering Machine 202A
Were they not ac. Something rings a bell, just look for the absence of a bridge
(or presence) |
12th Jan 2017, 3:19 pm | #7 |
Dekatron
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Re: BT Robin - Answering Machine 202A
That could be why there aren't any polarity markings?
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12th Jan 2017, 3:59 pm | #8 |
Dekatron
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Re: BT Robin - Answering Machine 202A
In that case (AC) there will be a bridge.If I find my psu I will put it up FOC as I certainly dont have that Robin anymore.
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12th Jan 2017, 4:58 pm | #9 |
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Re: BT Robin - Answering Machine 202A
On the other hand, the lack of them could simply be, as with the lack of any voltage indication, that it was simply expected to be run from a supplied PSU - so knowledge of what flowed between them was not considered necessary.
By the way, if the above-mentioned PSU is found, measurement and publication of its output would be useful before it's rehomed.
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Mending is better than Ending (cf Brave New World by Aldous Huxley) |
12th Jan 2017, 5:15 pm | #10 |
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Re: BT Robin - Answering Machine 202A
Will do Dave.
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12th Jan 2017, 6:58 pm | #11 |
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Re: BT Robin - Answering Machine 202A
I guess they were concerned that anything but an original PSU might invalidate the BABT approval of the answering machine, so avoided anything (like marking the voltage and polarity) that might encourage users to try substituting their own. Under the right (unlikely, but by no stretch impossible) combination of circumstances, a fault could damage the exchange -- or even other subscribers' equipment.
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12th Jan 2017, 7:28 pm | #12 |
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Re: BT Robin - Answering Machine 202A
Good comment Julie.
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12th Jan 2017, 9:59 pm | #13 |
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Re: BT Robin - Answering Machine 202A
In this sort of situation, I usually check the polarity and approximate voltage by examining the electrolytic caps. I then start with perhaps 1/3 of their rated voltage, and slowly wind it up until the thing starts to work properly. Add about 20%, and that will usually do.
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