Ekco T161 - Page 7 - UK Vintage Radio Repair and Restoration Discussion Forum

murphyv310 · 15th Aug 2009, 10:23 pm

Hi
As John says there will not be any Hiss from the sound under no signal condition, this repair may be difficult without hands on help, especially if you are not that technical.
I would suggest a day with an experienced engineer that is good with valve technology.
A wee plug here, You can always bring up to the Scottish meet in October.
Good Luck
Trevor

Heatercathodeshort · 16th Aug 2009, 9:04 am

That is a great idea Trevor. I must admit I was thinking along the same lines myself. A television receiver even these simple Ekco receivers need experience of radio servicing at least to effect a satisfactory repair. Even with all the help we can offer I fear it will be a difficult job for I.B. to carry this through.
Do you think you can manage to get the 161 to the Scottish meet Trevor mentions? It will be well worth the visit and make a few new friends. Regards, John.

Electricdreams · 16th Aug 2009, 7:59 pm

Ok, I'll look into getting the T161 to the meet, meanwhile I'll get my father to look at it. He has more experience with valves than I do (and he's a lecturer in engineering at local university)

I measured the HT and it comes up with zero on the meter. (DC If that is right)

I'll email my father tomorrow to see if he can come around to take a peek.

I just hope the tube isn't soft!!!

Steve_P · 16th Aug 2009, 8:23 pm

Well if the HT is at 0v then that is easy to trace. Have a go.

Trader Sheet 1039 refers. Are the valves lit? If not, measure the AC on the On-Off switch (across both pins) and then R75/76. This should narrow down the fault.

If the valves are lit, then on DC between C66 and C65. If it's not there, go back to V9. This is the rectifier and the efficency diode for the line output stages. Might want changing. Even check across pieces of wire - it's amazing what you can find...

If you're not sure then don't, but have a go...

Cheers,

Steve P.

Electricdreams · 16th Aug 2009, 8:47 pm

I've just tried again with another meter and it came up with 137v DC..

Steve_P · 16th Aug 2009, 10:12 pm

That's low. Try changing the valve and the caps.

Cheers,

Steve P.

Electricdreams · 16th Aug 2009, 10:21 pm

Which valve?

The U801 is brand new as well as the smoothing caps...

It started at 177 with the limiter and fell to 137 and stays at that voltage.

Electricdreams · 17th Sep 2009, 7:03 pm

I've not forgotten this thread, I am currently saving up for a Aurora..

So watch this space..

murphyv310 · 17th Sep 2009, 9:01 pm

Quote:

Originally Posted by idlerbiker

Which valve?

The U801 is brand new as well as the smoothing caps...

It started at 177 with the limiter and fell to 137 and stays at that voltage.

Hi.
This what I would expect with a lamp limiter. Its time to feed the set with mains, I would think the set will now work unless you have done something silly.
One thing to always remember, "respect electricity but don't be frightened of it".
If it goes bang switch off and then look around, bet you it works though.
Cheers
Trevor

Electricdreams · 10th Oct 2009, 2:17 pm

I've taken the Set to Steve_P last Saturday and he was kind enough to take a look at it for me, he suggested I measure the resistors, so here they are,

R81 is 30v
R83 is 177v
R87 is 15v
R92 is 100v

I haven't got around to R94 yet as it involves getting the chassis out again (and I'm just having lunch)

is this information useful to getting closer to the culprit? He also suggested I replace the Line output valve.

Steve_P · 10th Oct 2009, 11:59 pm

There are some caps in the line oscillator stage. Change these.

Cheers,

Steve P.

Electricdreams · 18th Oct 2009, 9:30 pm

I've replaced the caps, and C73 went pop after powering up. I'm wondering if it to do with the old valve. The replacement valve arrived yesterday, so I might replace that cap and valve, then power it up on the lamp limiter. (to see if I can prevent c73 from popping again)

Any other suggestions welcome.

Lloyd 1985 · 18th Oct 2009, 10:05 pm

Hi

I've no idea about this particular set, but was C73 an electrolytic cap? if it is, then it might have been connected backwards, and the reverse polarity would have made it go bang! check with a meter to see what the polarity is. and probably best to wait for the new valve too

regards,
Lloyd

Electricdreams · 18th Oct 2009, 10:22 pm

Oh I've checked that, it's not a electrolytic cap, just a small ceramic of only 40pf, (replaced by a modern 47pf)

The Voltage range are identical, my mistake it's C72 not C73

Lloyd 1985 · 18th Oct 2009, 10:53 pm

hmm.. I've never seen a ceramic cap go pop before! maybe it'll be ok with the new valve and a new cap. if it blows the cap up again, then there's probably another part faulty.

15th Aug 2009, 10:23 pm	#121
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,422	Re: Ekco T161 Hi As John says there will not be any Hiss from the sound under no signal condition, this repair may be difficult without hands on help, especially if you are not that technical. I would suggest a day with an experienced engineer that is good with valve technology. A wee plug here, You can always bring up to the Scottish meet in October. Good Luck Trevor __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

16th Aug 2009, 9:04 am	#122
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Ekco T161 That is a great idea Trevor. I must admit I was thinking along the same lines myself. A television receiver even these simple Ekco receivers need experience of radio servicing at least to effect a satisfactory repair. Even with all the help we can offer I fear it will be a difficult job for I.B. to carry this through. Do you think you can manage to get the 161 to the Scottish meet Trevor mentions? It will be well worth the visit and make a few new friends. Regards, John.

16th Aug 2009, 7:59 pm	#123
Electricdreams Hexode Join Date: Mar 2008 Location: Manchester, UK. Posts: 478	Re: Ekco T161 Ok, I'll look into getting the T161 to the meet, meanwhile I'll get my father to look at it. He has more experience with valves than I do (and he's a lecturer in engineering at local university) I measured the HT and it comes up with zero on the meter. (DC If that is right) I'll email my father tomorrow to see if he can come around to take a peek. I just hope the tube isn't soft!!! __________________ What have you bought now??

16th Aug 2009, 8:23 pm	#124
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Ekco T161 Well if the HT is at 0v then that is easy to trace. Have a go. Trader Sheet 1039 refers. Are the valves lit? If not, measure the AC on the On-Off switch (across both pins) and then R75/76. This should narrow down the fault. If the valves are lit, then on DC between C66 and C65. If it's not there, go back to V9. This is the rectifier and the efficency diode for the line output stages. Might want changing. Even check across pieces of wire - it's amazing what you can find... If you're not sure then don't, but have a go... 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...?

16th Aug 2009, 8:47 pm	#125
Electricdreams Hexode Join Date: Mar 2008 Location: Manchester, UK. Posts: 478	Re: Ekco T161 I've just tried again with another meter and it came up with 137v DC.. __________________ What have you bought now??

16th Aug 2009, 10:12 pm	#126
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Ekco T161 That's low. Try changing the valve and the caps. 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...?

16th Aug 2009, 10:21 pm	#127
Electricdreams Hexode Join Date: Mar 2008 Location: Manchester, UK. Posts: 478	Re: Ekco T161 Which valve? The U801 is brand new as well as the smoothing caps... It started at 177 with the limiter and fell to 137 and stays at that voltage. __________________ What have you bought now??

17th Sep 2009, 7:03 pm	#128
Electricdreams Hexode Join Date: Mar 2008 Location: Manchester, UK. Posts: 478	Re: Ekco T161 I've not forgotten this thread, I am currently saving up for a Aurora.. So watch this space.. __________________ What have you bought now??

10th Oct 2009, 2:17 pm	#130
Electricdreams Hexode Join Date: Mar 2008 Location: Manchester, UK. Posts: 478	Re: Ekco T161 I've taken the Set to Steve_P last Saturday and he was kind enough to take a look at it for me, he suggested I measure the resistors, so here they are, R81 is 30v R83 is 177v R87 is 15v R92 is 100v I haven't got around to R94 yet as it involves getting the chassis out again (and I'm just having lunch) is this information useful to getting closer to the culprit? He also suggested I replace the Line output valve. __________________ What have you bought now??

10th Oct 2009, 11:59 pm	#131
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Ekco T161 There are some caps in the line oscillator stage. Change these. 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...?

18th Oct 2009, 9:30 pm	#132
Electricdreams Hexode Join Date: Mar 2008 Location: Manchester, UK. Posts: 478	Re: Ekco T161 I've replaced the caps, and C73 went pop after powering up. I'm wondering if it to do with the old valve. The replacement valve arrived yesterday, so I might replace that cap and valve, then power it up on the lamp limiter. (to see if I can prevent c73 from popping again) Any other suggestions welcome. __________________ What have you bought now??

18th Oct 2009, 10:05 pm	#133
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,819	Re: Ekco T161 Hi I've no idea about this particular set, but was C73 an electrolytic cap? if it is, then it might have been connected backwards, and the reverse polarity would have made it go bang! check with a meter to see what the polarity is. and probably best to wait for the new valve too regards, Lloyd

18th Oct 2009, 10:22 pm	#134
Electricdreams Hexode Join Date: Mar 2008 Location: Manchester, UK. Posts: 478	Re: Ekco T161 Oh I've checked that, it's not a electrolytic cap, just a small ceramic of only 40pf, (replaced by a modern 47pf) The Voltage range are identical, my mistake it's C72 not C73 __________________ What have you bought now??

18th Oct 2009, 10:53 pm	#135
Lloyd 1985 Nonode Join Date: Jun 2008 Location: Coningsby, Lincolnshire, UK. Posts: 2,819	Re: Ekco T161 hmm.. I've never seen a ceramic cap go pop before! maybe it'll be ok with the new valve and a new cap. if it blows the cap up again, then there's probably another part faulty.