Marconiphone T69 Da - no reception - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Station X · 31st May 2009, 9:50 am

Looking at the bottom or wiring side of a valveholder the pins number clockwise from the gap or spigot. Readings are taken between the chassis and the pin.

Do you mean resistor colour code rather than capacitor? When giving measurements you need to quote units or they're useless. The colour code you quote is for a 47K (47000) ohm resistor.

Steve_P · 31st May 2009, 10:00 am

For the VHF, try another UCC85.

Check the voltages on the UCH81 like Station X says above. Capacitors round the oscillator stage at a guess for LW.

Cheers,

Steve P.

benjamin77 · 31st May 2009, 1:14 pm

A success ...well nearly, it's now working on VHF and MW so just LW to tackle !

Steve_P · 31st May 2009, 1:29 pm

Measure the volts on the valve on MW and LW and get back to us.

Also, with the set off, switch to MW and go between Earth and pin 4 of the front of the wavechange switch. Just to prove L9 is OK.

Cheers,

Steve P.

benjamin77 · 31st May 2009, 5:51 pm

Ok have now taken some reading from valve 2 ....correctly I hope.

Lw Mw
Pin 1 10v 5v
pin 2 64v 70v
pin 3 6v 5v
pin 4 127v 127v
pin 5 0v 0v
pin 6 0v 0v
pin 7 0v 0v
pin 8 0v 0v
pin 9 54v 54v

I am assuming that L9 is ok as when I test its contuniaty with a MM it bleeps.....

Cheers

Steve_P · 31st May 2009, 6:23 pm

Well, the pin numbering is wrong, but that can be corrected...

Pin MW LW

1 54V 54V (Screen Grid of Mixer)
2 0V 0V (Grid 1 of Mixer)
3 0V 0V (Cathode)
4 + 5 Heaters
6 127V 127V (Anode of Mixer)
7 6V 5V (Grid 3 of Mixer)
8 64V 70V (Anode of Oscillator)
9 10V 5V (Grid of Oscillator)

If someone could prove I have done my correcting correctly I would be pleased.

L9 Looks OK to me.

Right - Next test. Radio on and turn it to 1500m / 200kHz : Radio 4. It used to be the light programme in days of old.

Get a portable set and put it close to the UCH81 and tune it to Radio 5 live at 433 Metres (693 kHz) and rock the tuning about on the Marconiphone set. You should hear the portable go quiet or whistle at some point. If you do, then the problem is on the aerial side of the set. If not, it's probably the oscillator stage.

Try a UCH81 (You never know) and then I would check caps in this area. Give the wavechange switch another clean. If you haven't done so already, change capacitor C34. C21 and check the wiring to the antenna coil and the coil itself.

Cheers,

Steve P.

Dave Moll · 31st May 2009, 8:15 pm

In that case, you are saying that pins 4 & 5 (heaters) are both at 0v, which implies that the heater supply is not getting through

Steve_P · 31st May 2009, 8:21 pm

Well, the heaters are at AC aren't they. It's 100mA and 19v heater. It might show zero it depends on his meter, but measuring AC on a DC meter would give close to zero.

Let's see what he comes back with.

Cheers,

Steve P.

Dave Moll · 31st May 2009, 8:27 pm

Ah yes, temporarily forgot that the average amplitude of a sine wave is zero

benjamin77 · 31st May 2009, 9:02 pm

Swapped out the valve for another that I thought was wasnt working in an Ekco set that I have and there is no change . So my next step would be to change the caps you suggest but although I can see them on the wiring diagram I am struggling to locate them on the pcb.

I have also checked the wiring to the antenna coil and it is un broken and looks ok.

Thanks for your patience.
Ben

Steve_P · 31st May 2009, 9:06 pm

No worries. It's what we are here for.

Get a valve from a set that works (or a new one!) and try that. No luck with the other radio test?

Anyway, check all the individual bits on the board, and if it's on a circuit board, do all the joints anyway. A dry joint somewhere perhaps?

Good luck...

Cheers,

Steve P.

Station X · 31st May 2009, 9:50 pm

Your pin numbering looks fine to me Steve. Makes me wonder where I went wrong in describing pin numbering. I've taken the liberty of editing in the electrode names.

benjamin77 · 31st May 2009, 10:27 pm

Ok its getting late so I will make this the last one of the day...

Tried the second radio test, as I tuned in the Marconiphone set the portable whistled through its speaker as though I was tuning it in...!

I guess this means that the oscillator section is working ... I think I will go back to the wave change switch and give it another going over, wave change switches seem to be the root of all evil !

If that dont work well what next ?

benjamin77 · 31st May 2009, 10:43 pm

Sorry Graham..It would maybe seem that I read the pin numbers from the top of the pcb not below as you had described

Steve_P · 31st May 2009, 11:03 pm

What next - C21, R11, C22. Put an aerial onto Pin 2 (Grid) of V2 and see what happens then.

Cheers,

Steve P.

benjamin77 · 1st Jun 2009, 10:30 am

I connected a makeshift arial to Pin 2 on V2 but no change...

Can some one confirm my suspicions......To locate the correct resistor (R11) on the PCB I would be looking for one colour coded brown,black,yellow giving 100 kohms as stated on the wiring diagram. C22 looks like it is connected directly accross the wave change switch and R11 is connected to the tuning block ?

I am probably wrong but hey I dont know If I dont ask...
Cheers

Station X · 1st Jun 2009, 11:02 am

I always think of the colour code like this:-

First band is first digit
Second band is second digit.
Third band is number of zeroes dollowing first two digits.

So Brown, Black, Yellow is 10 0000 ohms or 100K ohms.

AlanBeckett · 1st Jun 2009, 11:09 am

There is of course a mnemonic to help remember the colours, but in these PC days .......

Station X · 1st Jun 2009, 11:47 am

I still use the non PC version because I learned it about 50 years ago and it's far too embedded in my brain for me to change.

PC versions are:-

Bad Beer Rots Our Young Guts But Vodka Goes Well

and

Bye Bye Rosie, Off You Go, Bristol Via Great Western

We'd better stay on topic though or I'll have to give myself another infraction.

benjamin77 · 2nd Jun 2009, 6:54 pm

A Success...! Replaced R11 and C22 also popped in a new UCH81 and hey presto its working well on all bands. Surprisingly its got good volume and the reception to my ear is above expected considering this is a cheap set!

When I get the pictures downloaded I will post them on here for scrutinisation !

Would like to say a big thank you to all that helped

many thanks for your patience

Now just to sort out my 2 little ECKO's

31st May 2009, 9:50 am	#21
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Marconiphone T69 Da - no reception Looking at the bottom or wiring side of a valveholder the pins number clockwise from the gap or spigot. Readings are taken between the chassis and the pin. Do you mean resistor colour code rather than capacitor? When giving measurements you need to quote units or they're useless. The colour code you quote is for a 47K (47000) ohm resistor. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

31st May 2009, 10:00 am	#22
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Marconiphone T69 Da - no reception For the VHF, try another UCC85. Check the voltages on the UCH81 like Station X says above. Capacitors round the oscillator stage at a guess for LW. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

31st May 2009, 1:14 pm	#23
benjamin77 Retired Dormant Member Join Date: May 2009 Location: High Wycombe, Buckinghamshire, UK. Posts: 326	Re: Marconiphone T69 Da - no reception A success ...well nearly, it's now working on VHF and MW so just LW to tackle !

31st May 2009, 1:29 pm	#24
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Marconiphone T69 Da - no reception Measure the volts on the valve on MW and LW and get back to us. Also, with the set off, switch to MW and go between Earth and pin 4 of the front of the wavechange switch. Just to prove L9 is OK. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

31st May 2009, 5:51 pm	#25
benjamin77 Retired Dormant Member Join Date: May 2009 Location: High Wycombe, Buckinghamshire, UK. Posts: 326	Re: Marconiphone T69 Da - no reception Ok have now taken some reading from valve 2 ....correctly I hope. Lw Mw Pin 1 10v 5v pin 2 64v 70v pin 3 6v 5v pin 4 127v 127v pin 5 0v 0v pin 6 0v 0v pin 7 0v 0v pin 8 0v 0v pin 9 54v 54v I am assuming that L9 is ok as when I test its contuniaty with a MM it bleeps..... Cheers

31st May 2009, 6:23 pm	#26
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Marconiphone T69 Da - no reception Well, the pin numbering is wrong, but that can be corrected... Pin MW LW 1 54V 54V (Screen Grid of Mixer) 2 0V 0V (Grid 1 of Mixer) 3 0V 0V (Cathode) 4 + 5 Heaters 6 127V 127V (Anode of Mixer) 7 6V 5V (Grid 3 of Mixer) 8 64V 70V (Anode of Oscillator) 9 10V 5V (Grid of Oscillator) If someone could prove I have done my correcting correctly I would be pleased. L9 Looks OK to me. Right - Next test. Radio on and turn it to 1500m / 200kHz : Radio 4. It used to be the light programme in days of old. Get a portable set and put it close to the UCH81 and tune it to Radio 5 live at 433 Metres (693 kHz) and rock the tuning about on the Marconiphone set. You should hear the portable go quiet or whistle at some point. If you do, then the problem is on the aerial side of the set. If not, it's probably the oscillator stage. Try a UCH81 (You never know) and then I would check caps in this area. Give the wavechange switch another clean. If you haven't done so already, change capacitor C34. C21 and check the wiring to the antenna coil and the coil itself. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

31st May 2009, 8:15 pm	#27
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,130	Re: Marconiphone T69 Da - no reception In that case, you are saying that pins 4 & 5 (heaters) are both at 0v, which implies that the heater supply is not getting through __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

31st May 2009, 8:21 pm	#28
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Marconiphone T69 Da - no reception Well, the heaters are at AC aren't they. It's 100mA and 19v heater. It might show zero it depends on his meter, but measuring AC on a DC meter would give close to zero. Let's see what he comes back with. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

31st May 2009, 8:27 pm	#29
Dave Moll Dekatron Join Date: Feb 2005 Location: West Cumbria (CA13), UK Posts: 6,130	Re: Marconiphone T69 Da - no reception Ah yes, temporarily forgot that the average amplitude of a sine wave is zero __________________ Mending is better than Ending (cf Brave New World by Aldous Huxley)

31st May 2009, 9:02 pm	#30
benjamin77 Retired Dormant Member Join Date: May 2009 Location: High Wycombe, Buckinghamshire, UK. Posts: 326	Re: Marconiphone T69 Da - no reception Swapped out the valve for another that I thought was wasnt working in an Ekco set that I have and there is no change . So my next step would be to change the caps you suggest but although I can see them on the wiring diagram I am struggling to locate them on the pcb. I have also checked the wiring to the antenna coil and it is un broken and looks ok. Thanks for your patience. Ben

31st May 2009, 9:06 pm	#31
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Marconiphone T69 Da - no reception No worries. It's what we are here for. Get a valve from a set that works (or a new one!) and try that. No luck with the other radio test? Anyway, check all the individual bits on the board, and if it's on a circuit board, do all the joints anyway. A dry joint somewhere perhaps? Good luck... Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

31st May 2009, 9:50 pm	#32
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Marconiphone T69 Da - no reception Your pin numbering looks fine to me Steve. Makes me wonder where I went wrong in describing pin numbering. I've taken the liberty of editing in the electrode names. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

31st May 2009, 10:27 pm	#33
benjamin77 Retired Dormant Member Join Date: May 2009 Location: High Wycombe, Buckinghamshire, UK. Posts: 326	Re: Marconiphone T69 Da - no reception Ok its getting late so I will make this the last one of the day... Tried the second radio test, as I tuned in the Marconiphone set the portable whistled through its speaker as though I was tuning it in...! I guess this means that the oscillator section is working ... I think I will go back to the wave change switch and give it another going over, wave change switches seem to be the root of all evil ! If that dont work well what next ?

31st May 2009, 10:43 pm	#34
benjamin77 Retired Dormant Member Join Date: May 2009 Location: High Wycombe, Buckinghamshire, UK. Posts: 326	Re: Marconiphone T69 Da - no reception Sorry Graham..It would maybe seem that I read the pin numbers from the top of the pcb not below as you had described

31st May 2009, 11:03 pm	#35
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Marconiphone T69 Da - no reception What next - C21, R11, C22. Put an aerial onto Pin 2 (Grid) of V2 and see what happens then. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

1st Jun 2009, 10:30 am	#36
benjamin77 Retired Dormant Member Join Date: May 2009 Location: High Wycombe, Buckinghamshire, UK. Posts: 326	Re: Marconiphone T69 Da - no reception I connected a makeshift arial to Pin 2 on V2 but no change... Can some one confirm my suspicions......To locate the correct resistor (R11) on the PCB I would be looking for one colour coded brown,black,yellow giving 100 kohms as stated on the wiring diagram. C22 looks like it is connected directly accross the wave change switch and R11 is connected to the tuning block ? I am probably wrong but hey I dont know If I dont ask... Cheers

1st Jun 2009, 11:02 am	#37
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Marconiphone T69 Da - no reception I always think of the colour code like this:- First band is first digit Second band is second digit. Third band is number of zeroes dollowing first two digits. So Brown, Black, Yellow is 10 0000 ohms or 100K ohms. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

1st Jun 2009, 11:09 am	#38
AlanBeckett Rest in Peace Join Date: Dec 2008 Location: Burton upon Trent, East Staffordshire, UK. Posts: 1,686	Re: Marconiphone T69 Da - no reception There is of course a mnemonic to help remember the colours, but in these PC days .......

1st Jun 2009, 11:47 am	#39
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: Marconiphone T69 Da - no reception I still use the non PC version because I learned it about 50 years ago and it's far too embedded in my brain for me to change. PC versions are:- Bad Beer Rots Our Young Guts But Vodka Goes Well and Bye Bye Rosie, Off You Go, Bristol Via Great Western We'd better stay on topic though or I'll have to give myself another infraction. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

2nd Jun 2009, 6:54 pm	#40
benjamin77 Retired Dormant Member Join Date: May 2009 Location: High Wycombe, Buckinghamshire, UK. Posts: 326	Re: Marconiphone T69 Da - no reception A Success...! Replaced R11 and C22 also popped in a new UCH81 and hey presto its working well on all bands. Surprisingly its got good volume and the reception to my ear is above expected considering this is a cheap set! When I get the pictures downloaded I will post them on here for scrutinisation ! Would like to say a big thank you to all that helped many thanks for your patience Now just to sort out my 2 little ECKO's