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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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4th Jan 2019, 4:01 pm | #1 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
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R1155 D/F meter
Hi Gents, I'm building a PSU for one of these sets and it will incorporate the D/F meter.
The leads to the meter are quite straightforward from the circuitry, but why are LT +, LT- run to P2, the visual indicator connector (8 pin); as well as connections to V9 a and b grids and V8 (DDT) anode (audio?). Can these connections be used for a sig strength meter, or an audio feed to an amplifier? Thanks, Ed |
4th Jan 2019, 7:11 pm | #2 |
Nonode
Join Date: May 2007
Location: Preston, Lancashire, UK.
Posts: 2,510
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Re: R1155 D/F meter
Ed,
How much information are you working with? The attached diagram may be of use to you, although whether it answers your question I'm not sure...…….. Andy |
4th Jan 2019, 7:25 pm | #3 |
Dekatron
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,385
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Re: R1155 D/F meter
Is there provision for a backlight bulb in the meter case, i.e. so that it would only be lit when the receiver was powered and thus relevant (perhaps also via an instrument lighting switch pole)?
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4th Jan 2019, 7:38 pm | #4 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,188
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Re: R1155 D/F meter
I thought the 'visual indicator' (2 meter movements with pointers that cross over the dial) had (radioactive) luminous paint on the pointers and dial markings. No internal bulb.
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4th Jan 2019, 8:10 pm | #5 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
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Re: R1155 D/F meter
The mounting for meter is illuminated, not the meter itself.
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4th Jan 2019, 9:17 pm | #6 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 8,171
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Re: R1155 D/F meter
Hi Gents, thanks for the info. I have full schematics and on some of them are shown the connections to plug P2 on the 1155. 3 leads from this are obviously for the meter, but of the other 5, 2 are LT + & -, one appears to be audio output from the anode of V8, the DDT, and the remaining 2 are the grids of V9 the double triode meter driving valve.
As the obviously are intended to go somewhere, I wondered what circuitry they could drive? Ed |
4th Jan 2019, 9:21 pm | #7 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: R1155 D/F meter
Would it be anything to do with test rig?
Lawrence. |
4th Jan 2019, 9:23 pm | #8 |
Nonode
Join Date: May 2007
Location: Preston, Lancashire, UK.
Posts: 2,510
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Re: R1155 D/F meter
There a lot of 'urban myths' regarding the DF meter!
1. There is no provision for lighting inside the meter. 2. The meter is not radioactive. 3. The standard wartime fit, certainly in the Lancaster, did not have the external lamp-holder mounted above it. This appeared post-war, and can be seen, for example, in Lancaster NX611 'Just Jane'. Andy |
4th Jan 2019, 10:02 pm | #9 |
Nonode
Join Date: May 2007
Location: Preston, Lancashire, UK.
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Re: R1155 D/F meter
Ed,
I can't find any wiring diagrams where those four pins are connected to any external circuitry. I'm wondering if they were provisioned in the receiver design at 'day one' for some purpose never subsequently implemented. Or, as Lawrence suggests, some purpose on a test-rig. Further digging is called for...……. Andy |
6th Jan 2019, 4:40 pm | #10 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,637
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Re: R1155 D/F meter
No provision in this test set. It is dated 1947 again, but says it'a a reprint.
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6th Jan 2019, 5:50 pm | #11 |
Heptode
Join Date: Jul 2009
Location: Newcastle upon Tyne, Tyne & Wear, UK.
Posts: 722
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Re: R1155 D/F meter
Hi Ed
Why not take the meter apart and see if the terminals actually have any internal connections? If they don't then they may just have been handy terminal posts if they do connect to something then you may ahve some clues as to what the fucntion was. Cheers James |
6th Jan 2019, 6:16 pm | #12 |
Nonode
Join Date: May 2007
Location: Preston, Lancashire, UK.
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Re: R1155 D/F meter
James,
You've got the wrong end of the stick! The pins Ed is questioning are on the eight-pin Jones connector on the receiver to which the meter is connected. Four pins are wired to the meter (Left, Right, Common, Screen). The other four pins are wired internally in the receiver, but don't have any known purpose which is explained in any information I've looked at. As I say in post #9, I think they must either have been provisioned for some purpose never implemented, or maybe used for test purposes. Agreed, the Test Set Type 65 does not use them. Andy |
6th Jan 2019, 8:42 pm | #13 |
Nonode
Join Date: May 2007
Location: Preston, Lancashire, UK.
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Re: R1155 D/F meter
OK, I’ve found a reference to the use of these pins for test purposes, although whether they were provided for this reason or just taken advantage of because they were already there, I can’t say.
Towards the back of AP2548A there is a Table headed Voltage Tests etc. Test of LT volts, withdraw meter plug P2 and measure across contacts 4 and 5, should read 6 to 7.5 volts. Test of HT volts, withdraw meter plug P2 and measure across contacts 4 and 6, should read 200 volts approx. . AF oscillator – measure across pins 7 and 8 using ac range of testmeter, should read 28 volts at 30 c/s, 35 volts at 80 c/s. (30c/s or 80 c/s determined by ‘speed’ switch). Andy |
6th Jan 2019, 8:43 pm | #14 |
Dekatron
Join Date: Jan 2004
Location: Newcastle upon Tyne, Tyne & Wear, UK.
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Re: R1155 D/F meter
Hi Gents, further digging in the 1155 circuit seems to suggest that phones could be connected to the feed from the DDT anode; possibly a pot across the grids of V9 as a sensitivity control and maybe the LT supplies for an indicator lamp?
Discuss Thanks, Ed |
6th Jan 2019, 10:02 pm | #15 |
Heptode
Join Date: Jul 2009
Location: Newcastle upon Tyne, Tyne & Wear, UK.
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Re: R1155 D/F meter
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6th Jan 2019, 10:39 pm | #16 | |
Octode
Join Date: Aug 2008
Location: Rotherham, South Yorkshire, UK.
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Re: R1155 D/F meter
Quote:
Peter |
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6th Jan 2019, 10:55 pm | #17 |
Nonode
Join Date: May 2007
Location: Preston, Lancashire, UK.
Posts: 2,510
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Re: R1155 D/F meter
Peter, I have also had that problem!
I concluded that the problem was two-fold, the bakelite swells up because it absorbs moisture, and the metal develops corrosion between it and the bakelite. Patience is vital. Keep the meter somewhere warm and dry for a few weeks, and dribble penetrating oil between metal and bakelite. Once the can moves a bit, reapply the oil and wipe away any muck which escapes, proceeding slowly As you say, meter movements go open-circuit. Andy |