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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE! |
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21st Jul 2015, 7:43 pm | #1 |
Octode
Join Date: Nov 2010
Location: Cullompton, Devon, UK.
Posts: 1,435
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Ekco U362, Ferranti U1032 DM70 Substitution
Having resurrected this sorry excuse for a radio (very unloved), I noticed the DM70 was a shadow of its former self with no display, not wanting to spend £12 on a replacement Knowing the radio was worth very little, I decided to go down the road of LED display, more experiment than anything, the result was quite acceptable, the total cost was around £2-00, the design uses five leds, one I/C one capacitor, two resistors and a pot, HT is drawn from the cathode of UL84, so easy and cheap replacement.
John |
21st Jul 2015, 9:38 pm | #2 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,843
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Re: Ekco U362, Ferranti U1032 DM70 Substitution
Clever!
Could you post your circuit? Would love to see it cased-up (i.e. behind the dial) too. N. |
22nd Jul 2015, 11:13 am | #3 |
Heptode
Join Date: Jul 2008
Location: Selby, North Yorkshire, UK.
Posts: 979
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Re: Ekco U362, Ferranti U1032 DM70 Substitution
In my Ekco U353 I substituted a DM71 that I got for £2 - same as a DM70, but with pins rather than leads. So I just soldered leads on Pity the rest of the radio expired in a quite smoky way not long afterwards
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22nd Jul 2015, 3:20 pm | #4 |
Octode
Join Date: Nov 2010
Location: Cullompton, Devon, UK.
Posts: 1,435
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Re: Ekco U362, Ferranti U1032 DM70 Substitution
Hi Nick
Have not finished the case repairs so just hung the dial so you can see what it will look like, I have used green 3mm leds but I seem to recollect that DMs were blue? I have not seen a working one for over 50 years so a little foggy. one of pictures is with no station tuned, the other has. I have drawn out a diagram of the unit I made, you will have to play around and perhaps fit a extra resistor if the cathode voltage is higher,though it does not seem that fussy, adjustment for full array via 220k pot. As you can see only four leds displayed as the apperature is not big enough for five, so one is hidden, it looked awful bending the leds at different angles to fit. John Last edited by jonnybear; 22nd Jul 2015 at 3:25 pm. |
22nd Jul 2015, 3:49 pm | #5 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,843
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Re: Ekco U362, Ferranti U1032 DM70 Substitution
Very pretty, and thanks for the circuit.
The original DM- devices were the same colour as most magic eyes AFAIK, i.e. bluey green. Nick. |
22nd Jul 2015, 4:29 pm | #6 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,936
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Re: Ekco U362, Ferranti U1032 DM70 Substitution
DM70s have a bluey grey colour, but it might be difficult to reproduce that colour with standard LEDs unless you do something clever with 3 colour ones.
You may find it looks better with rectangular shaped LEDs stacked close together, like the LED meters on 1980s tuners and cassette decks. Good idea though, and nice and simple. |
22nd Jul 2015, 4:39 pm | #7 |
Dekatron
Join Date: Jan 2005
Location: Oxford, UK.
Posts: 17,843
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Re: Ekco U362, Ferranti U1032 DM70 Substitution
How about a bit frosted plastic or glass with the LEDs mounted some distance behind so they're more blurry?
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22nd Jul 2015, 4:39 pm | #8 |
Heptode
Join Date: Jul 2008
Location: Selby, North Yorkshire, UK.
Posts: 979
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Re: Ekco U362, Ferranti U1032 DM70 Substitution
My DM71 was more of a lightish blue, almost cyan. I've still got it somewhere.
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23rd Jul 2015, 1:35 pm | #9 |
Dekatron
Join Date: Aug 2013
Location: Wigan, Greater Manchester, UK.
Posts: 9,431
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Re: Ekco U362, Ferranti U1032 DM70 Substitution
Hi John,
Looks nice and neat, do more LED's light as the AGC voltage gets higher? Frank |
23rd Jul 2015, 5:02 pm | #10 |
Octode
Join Date: Nov 2010
Location: Cullompton, Devon, UK.
Posts: 1,435
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Re: Ekco U362, Ferranti U1032 DM70 Substitution
Hi Frank
as the signal reaches its optimum tuning, (the voltage on the agc gets higher)the leds follow one at a time until all are illuminated. John |