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Vintage Telephony and Telecomms Vintage Telephones, Telephony and Telecomms Equipment |
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25th May 2020, 11:08 am | #1 |
Heptode
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 598
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GPO Jack unit 1B and regulator 6B
Quick questions. Does this regulator do the same job as the reversible regulator in the 706 ?
If not, what exactly is its purpose and is it essential to have it fitted ? Thankyou. |
25th May 2020, 5:50 pm | #2 |
Triode
Join Date: May 2014
Location: Worcestershire, UK.
Posts: 37
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Re: GPO Jack unit 1B and regulator 6B
It was to prevent transmitter noise on short exchange lines or PBX extensions.
The jack units in my TRS used them, as we were just across the road from the exchange. My recollection is that there wouldn't necessarily be noise without it, but without cuent limiting by the 6B the transmitter insert in the headset could 'fry' in the long term. |
25th May 2020, 8:40 pm | #3 |
Heptode
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 598
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Re: GPO Jack unit 1B and regulator 6B
Thankyou 198.
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26th May 2020, 12:21 am | #4 |
Triode
Join Date: May 2014
Location: Worcestershire, UK.
Posts: 37
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Re: GPO Jack unit 1B and regulator 6B
..👍🏽
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28th May 2020, 12:44 pm | #5 | |
Heptode
Join Date: Jan 2008
Location: Hakadal, Norway
Posts: 643
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Re: GPO Jack unit 1B and regulator 6B
Quote:
dsk |
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28th May 2020, 6:20 pm | #6 |
Heptode
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 598
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Re: GPO Jack unit 1B and regulator 6B
Here's a picture of the regulator. I've taken it out of the unit but it fits between T11 and T17 on the circuit board. It appears to be two similar-looking components soldered to a coil. More than that I really can't say!
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28th May 2020, 7:12 pm | #7 |
Dekatron
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 6,130
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Re: GPO Jack unit 1B and regulator 6B
The "two similar-looking components" look like diodes to me - in opposed polarity.
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28th May 2020, 7:36 pm | #8 | |
Heptode
Join Date: Jan 2008
Location: Hakadal, Norway
Posts: 643
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Re: GPO Jack unit 1B and regulator 6B
Quote:
dsk |
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28th May 2020, 8:53 pm | #9 |
Heptode
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 598
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Re: GPO Jack unit 1B and regulator 6B
I'm afraid I haven't a clue. I just put wires and straps and things where the experts tell me. The circuit board in this jack is largely based on that of the 746 telephone, but I've never seen this regulator in a 746, unless it has a different design.
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28th May 2020, 9:06 pm | #10 |
Dekatron
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 6,130
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Re: GPO Jack unit 1B and regulator 6B
I think that regulator is specific to the Jack 1B. I have a 1B with a similar one. The 700 series 'phones use a regulator of a completely different design.
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Mending is better than Ending (cf Brave New World by Aldous Huxley) |
28th May 2020, 9:39 pm | #11 |
Heptode
Join Date: Jan 2008
Location: Hakadal, Norway
Posts: 643
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Re: GPO Jack unit 1B and regulator 6B
Thank you any way, one day we will find it out.
dsk |
28th May 2020, 11:04 pm | #12 |
Heptode
Join Date: Jul 2007
Location: Flintshire, UK.
Posts: 707
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Re: GPO Jack unit 1B and regulator 6B
The Vocabulary of Engineering Stores states "only used with Jack Unit 1B (not earlier 1a) and used to stop 'frying noise' when used wit a Headset No 1"
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29th May 2020, 7:56 am | #13 |
Heptode
Join Date: Oct 2006
Location: Leeds, West Yorkshire, UK.
Posts: 598
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Re: GPO Jack unit 1B and regulator 6B
I wonder if the 3T earphone element had a problem with the jack unit ?
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29th May 2020, 8:22 am | #14 |
Heptode
Join Date: Apr 2011
Location: Edinburgh, UK.
Posts: 805
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Re: GPO Jack unit 1B and regulator 6B
The 3T was possibly more sensitive.
When used continuously by operators on public exchange switchboards, the receiver may be too loud for comfort. Under these circumstances the sensitivity should be reduced by shunting the receiver with a Resistor, Carbon, No. 4, 150 ohms. When used at PBXs this shunt is not required since an 180 ohm series resistor is provided in the operator's circuit. jack units for headsets were usually used on Key and Lamps. https://www.britishtelephones.com/head2.htm https://www.britishtelephones.com/jackunit1.htm What we'd do without Mr Freshwater's magnum opus website, I do not know. |
29th May 2020, 8:34 am | #15 |
Dekatron
Join Date: Feb 2005
Location: West Cumbria (CA13), UK
Posts: 6,130
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Re: GPO Jack unit 1B and regulator 6B
... and its companion archive of wiring diagrams from Sam Hallas.
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Mending is better than Ending (cf Brave New World by Aldous Huxley) |