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4th May 2020, 5:42 pm | #61 |
Hexode
Join Date: Mar 2008
Location: Margate, Kent, UK.
Posts: 355
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Re: Lockdown project - Sony TC-200
Hi guys , been to work today so just got back to it....Thanks for the circuit drawings ...that really helps loads.
Paul Last edited by Paulus.d; 4th May 2020 at 5:47 pm. |
4th May 2020, 5:59 pm | #62 | |
Hexode
Join Date: Mar 2008
Location: Margate, Kent, UK.
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Re: Lockdown project - Sony TC-200
Quote:
Right , I have possibly mixed up X201 for X101 .... so the OC140 is X101... The readings are .... Collector ...8.5v Base ...8.8v emiter..9.3v Paul |
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4th May 2020, 6:04 pm | #63 |
Hexode
Join Date: Mar 2008
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Re: Lockdown project - Sony TC-200
JUst for my own information I compared x201 with x101
collector 9.6v base 13.8v Emiter 9.6 The bases are different.. Paul |
4th May 2020, 6:29 pm | #64 | |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
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Re: Lockdown project - Sony TC-200
Quote:
With transistors the emitter voltage should always be less that the base voltage and in the case of germanium types by approx. 0.1 to 0.2 Volts (approx. 0.6 Volts for silicon types) As a final check, with the fault condition present measure the voltage between emitter and base of X101, -ve black probe to the emitter, +ve red probe to the base, do the same for X201 as a matter of interest. Lawrence. |
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4th May 2020, 7:56 pm | #65 |
Hexode
Join Date: Mar 2008
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Re: Lockdown project - Sony TC-200
x101 Emiter and base - .12 v X201 about the same.
Paul |
4th May 2020, 8:29 pm | #66 |
Dekatron
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Re: Lockdown project - Sony TC-200
I would replace the transistor.
Lawrence. |
4th May 2020, 8:39 pm | #67 |
Hexode
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Location: Margate, Kent, UK.
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Re: Lockdown project - Sony TC-200
If I switch the transistors... then that should do the trick...
Are the original ones still available? Paul |
4th May 2020, 9:18 pm | #68 |
Dekatron
Join Date: Apr 2011
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Re: Lockdown project - Sony TC-200
That depends if the other transistor is ok or not and whether or not the transistor in Ch1 is faulty.
I don't know if the originals are still available, a quick search will usually prove yes or no. Lawrence. |
4th May 2020, 9:28 pm | #69 |
Dekatron
Join Date: Apr 2019
Location: Worthing, West Sussex, UK.
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Re: Lockdown project - Sony TC-200
Can be difficult to find these very old Germanium transistors, especially for a reasonable cost.
Would be worth asking the Forum on the "Sets, Parts and Service Information Wanted". |
4th May 2020, 9:44 pm | #70 |
Dekatron
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Re: Lockdown project - Sony TC-200
Were you able to verify the number on X201 ?
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5th May 2020, 10:40 am | #71 |
Hexode
Join Date: Mar 2008
Location: Margate, Kent, UK.
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Re: Lockdown project - Sony TC-200
X201 is Sony D64 .... Theoriginal component for the unit ....X101 is the OC140...
Does Tandberg series 15 have any compatable transistors? I have parts of that model Paul |
5th May 2020, 10:59 am | #72 |
Hexode
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Re: Lockdown project - Sony TC-200
Swapping them made no difference..... sound still fades away.... Paul
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5th May 2020, 11:36 am | #73 |
Dekatron
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Re: Lockdown project - Sony TC-200
The original X101/201 according to schematics is 2SD64, which is what your X201 Sony D64 is.
Your X101 OC140 as far as I can see is not an original, that is why I previously asked if there were any signs of its soldering having been disturbed. I have not had time to check data sheets etc but according to radiomuseum.org (which is normally good) one of the equivalents for the 2SD64 is an AC176, which also according to radiomuseum one of the equivalents for the AC176 is an AC127. Your Tandberg 15 should have a AC127 for transistor Q106 (in power amp stage). There may well be many other Germanium transistors that would do, but it is always good ideally (if possible) to use the correct one or an equivalent. |
5th May 2020, 12:02 pm | #74 |
Hexode
Join Date: Mar 2008
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Re: Lockdown project - Sony TC-200
The soldering in this thing is awful...it looks like every joint has been reflowed badly and where i've just touched it the tracks are coming off the PCB...
Both of my transistors seem to be working...or alternatively are both damaged as swapping them did not cure the problem.. Ill dig out the AC127 and try it , just to be clear in my own mind.. Paul |
5th May 2020, 2:05 pm | #75 |
Hexode
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Re: Lockdown project - Sony TC-200
I've just cut the track at the wiper to channel 1's volume control and linked the wiper from channel 2 .....I can confurm the fault is only on channel 1's head pre amp ...
channel 2 is playing wonderfully .... I've also switched the head wiring too, so it's not the head..... Paul Last edited by Paulus.d; 5th May 2020 at 2:24 pm. |
5th May 2020, 2:28 pm | #76 |
Dekatron
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Re: Lockdown project - Sony TC-200
Good work, you are doing well !
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5th May 2020, 3:31 pm | #77 |
Hexode
Join Date: Mar 2008
Location: Margate, Kent, UK.
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Re: Lockdown project - Sony TC-200
Thank you... however keeping it playing while testing this has killed the Channel 1 pre amp..... there is now a very minimal sound from it ...
Paul |
6th May 2020, 1:19 pm | #78 |
Hexode
Join Date: Mar 2008
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Re: Lockdown project - Sony TC-200
Well, that's it..... Channel 1 is finally working normally All down to C109 50uf 15v cap across R107 ....
One last question, I'm I doing any harm allowing Channel 2 tpplay without an otput transformer Paul |
6th May 2020, 1:59 pm | #79 |
Dekatron
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Re: Lockdown project - Sony TC-200
Should be no problem, could remove the output pentode.
Cannot fully see how posts 75, 77 & 78 relate, but fantastic that you have fixed it, just need another output transformer now. |
6th May 2020, 2:09 pm | #80 |
Hexode
Join Date: Mar 2008
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Re: Lockdown project - Sony TC-200
The channel 1 sound came back after a couple of tries.... i found a 47uf 16v cap so tried it in there ...it's still playing now
woo hoo Paul |