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Vintage Amateur and Military Radio Amateur/military receivers and transmitters, morse, and any other related vintage comms equipment. |
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16th Sep 2019, 10:12 am | #1 |
Octode
Join Date: Jun 2006
Location: St Osyth, Nr Clacton, Essex, UK.
Posts: 1,482
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Mystery A.M. transformer
This is the transformer in the mystery RF device I recently offered. It has Air Ministry markings that look like 10M/162 or possibly 10A/162. It has about 10.5mm of laminations and the markings on one side are IP and OP with what looks like an unused tapping. On the other side it is marked OS, T2 and IS. I suppose these are all input/output, primary/secondary (apart from the "T2" connection).
Overall size is 5cm lamination length, 3.8cm max winding width and 2.9cm height. Coloured dark brown varnish. I wonder if, just out of curiosity and a sense of completion, anyone has the appropriate AP that would identify the characteristics of the transformer and/or the equipment it's likely to have come from. Speculation welcomed! Graham
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Half my stuff is junk - trouble is, I don't know which half! |
16th Sep 2019, 10:40 am | #2 |
Heptode
Join Date: Jan 2003
Location: Tewkesbury, Gloucestershire, UK.
Posts: 690
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Re: Mystery A.M. transformer
Without checking, it sounds as if it might be one of the transformers from the A1134 intercom amplifier as used in the Lancaster bomber (like the one shown here about 2/3 down the page):
http://www.tibblestone.com/oldradios...adio/T1154.htm If so, I'm afraid one or more of the windings is likely to be o/c.
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Keith Yates - G3XGW VMARS & BVWS member http://www.tibblestone.com/oldradios/Old_Radios.htm |
16th Sep 2019, 11:13 am | #3 |
Nonode
Join Date: May 2007
Location: Preston, Lancashire, UK.
Posts: 2,510
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Re: Mystery A.M. transformer
More likely 10K/162.
This is shown in AP1086 as a Transformer Type 285, LF Output, overall ratio 1:2 Andy |
16th Sep 2019, 11:45 am | #4 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 2,013
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Re: Mystery A.M. transformer
Would those need a beehive trimmer capacitor and what looks like an inductor with an adjustable core at bottom left?
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16th Sep 2019, 11:52 am | #5 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Mystery A.M. transformer
The chassis look like an electrickery backing box...
Lawrence. |
16th Sep 2019, 12:17 pm | #6 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
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Re: Mystery A.M. transformer
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16th Sep 2019, 12:33 pm | #7 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Mystery A.M. transformer
A 10K/162 transformer was used in the R1147 receiver.
Lawrence. |
16th Sep 2019, 1:06 pm | #8 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Mystery A.M. transformer
As a guess it might be for IFT alignment?
Lawrence. |
16th Sep 2019, 1:06 pm | #9 |
Nonode
Join Date: May 2007
Location: Preston, Lancashire, UK.
Posts: 2,510
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Re: Mystery A.M. transformer
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16th Sep 2019, 1:09 pm | #10 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Mystery A.M. transformer
Thanks to a Radio Constructor archive.
Lawrence. |
16th Sep 2019, 1:17 pm | #11 |
Nonode
Join Date: Nov 2015
Location: Welwyn Garden City, Hertfordshire, UK.
Posts: 2,013
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Re: Mystery A.M. transformer
Ah I see, a transformer re-used for a spot of home brew. Sorry I took a while to catch on.
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17th Oct 2019, 6:09 pm | #12 |
Heptode
Join Date: May 2015
Location: Chatham, Kent, UK.
Posts: 947
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Re: Mystery A.M. transformer
Thanks for device this is the circuit and valve line up pin numbers match resistor at top ht to anode is 56k
any one a clue as to where the green and the green/red wire would go also ideas on what it is ? thanks Mick Last edited by mickm3for; 17th Oct 2019 at 6:12 pm. Reason: missed word |
17th Oct 2019, 6:28 pm | #13 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
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Re: Mystery A.M. transformer
If the green wire is connected to the red/green wire, the double-triode becomes a "cathode-coupled oscillator" whose frequency is determined by the coil and capacitor.
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19th Oct 2019, 12:36 pm | #14 |
Heptode
Join Date: May 2015
Location: Chatham, Kent, UK.
Posts: 947
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Re: Mystery A.M. transformer
Hi thanks connected green to red green fitted ECC81 6v+200v ht and got a carrier on 1.45 mhz . the other stage i would think is a af osc ? (does not work) caps way off value/oc so transformer is used as a modulation transformer. i would think this is an alignment aid or a marker osc. Will recap and retest Mick
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19th Oct 2019, 1:02 pm | #15 |
Dekatron
Join Date: Apr 2012
Location: Wiltshire, UK.
Posts: 13,953
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Re: Mystery A.M. transformer
Yes the other stage is an audio oscillator - like you said it's set up to tone-modulate the RF-oscillator, so your 'thing' is indeed probably an alignment-aid/test-signal-source for the medium-wave band.
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19th Oct 2019, 4:49 pm | #16 | |
Heptode
Join Date: Jun 2012
Location: Southeast Norfolk, UK.
Posts: 772
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Re: Mystery A.M. transformer
Quote:
73 Roger Last edited by G3VKM_Roger; 19th Oct 2019 at 4:52 pm. Reason: spelling |
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