Ekco U362, Ferranti U1032 DM70 Substitution - UK Vintage Radio Repair and Restoration Discussion Forum

jonnybear · 21st Jul 2015, 7:43 pm

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

Nickthedentist · 21st Jul 2015, 9:38 pm

Clever!

Could you post your circuit? Would love to see it cased-up (i.e. behind the dial) too.

N.

richrussell · 22nd Jul 2015, 11:13 am

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

jonnybear · 22nd Jul 2015, 3:20 pm

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

Nickthedentist · 22nd Jul 2015, 3:49 pm

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.

paulsherwin · 22nd Jul 2015, 4:29 pm

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.

Nickthedentist · 22nd Jul 2015, 4:39 pm

How about a bit frosted plastic or glass with the LEDs mounted some distance behind so they're more blurry?

richrussell · 22nd Jul 2015, 4:39 pm

My DM71 was more of a lightish blue, almost cyan. I've still got it somewhere.

Nuvistor · 23rd Jul 2015, 1:35 pm

Hi John,
Looks nice and neat, do more LED's light as the AGC voltage gets higher?

Frank

jonnybear · 23rd Jul 2015, 5:02 pm

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

21st Jul 2015, 7:43 pm	#1
jonnybear Octode Join Date: Nov 2010 Location: Cullompton, Devon, UK. Posts: 1,435	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 Attached Thumbnails

21st Jul 2015, 9:38 pm	#2
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,843	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
richrussell Heptode Join Date: Jul 2008 Location: Selby, North Yorkshire, UK. Posts: 979	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

22nd Jul 2015, 3:20 pm	#4
jonnybear Octode Join Date: Nov 2010 Location: Cullompton, Devon, UK. Posts: 1,435	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 Attached Thumbnails Last edited by jonnybear; 22nd Jul 2015 at 3:25 pm.

22nd Jul 2015, 3:49 pm	#5
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,843	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
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,936	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
Nickthedentist Dekatron Join Date: Jan 2005 Location: Oxford, UK. Posts: 17,843	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?

23rd Jul 2015, 1:35 pm	#9
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,431	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
jonnybear Octode Join Date: Nov 2010 Location: Cullompton, Devon, UK. Posts: 1,435	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