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Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
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31st Jul 2019, 3:51 pm | #1 |
Octode
Join Date: Dec 2003
Location: Leeds, West Yorkshire, UK.
Posts: 1,592
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Bush TR130 208 B/S dead
Hi. I have managed to restore the l.w band on my Bush TR130 radio, although the m.w still requires a bit of attention (whistles while tuning on certain parts of the dial.
Would like to restore the 208 B/S as this is dead. The oscillator coil measures alright (no o/c windings). The resistors seem slightly out of tolerance in that section, but does not seem that bad to stop it oscillating. Any ideas? Cheers Mike |
31st Jul 2019, 7:31 pm | #2 |
Dekatron
Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,761
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Re: Bush TR130 208 B/S dead
Continuity of the Lux push button switch contacts? ('SC').
Alignment in the 208 switch position per the Bush datasheet (L8, 9 10 and C3)?
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David. BVWS Member. G-QRP Club member 1339. |
31st Jul 2019, 8:58 pm | #3 |
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Re: Bush TR130 208 B/S dead
Have you checked the RF decoupling electrolytic. C27 on the Trader sheet.
Mike |
1st Aug 2019, 2:21 pm | #4 |
Octode
Join Date: Dec 2003
Location: Leeds, West Yorkshire, UK.
Posts: 1,592
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Re: Bush TR130 208 B/S dead
Hi.
Many thanks for both replies. I have had a look at the 208 B/S switch, but can not see it out of alignment. Will try the other components like C27. Cheers Mike |
1st Aug 2019, 6:54 pm | #5 |
Dekatron
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Location: Croydon, Surrey, UK.
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Re: Bush TR130 208 B/S dead
I.F decoupling as mentioned above will cause whistling when tuned. Also if the RF alignment is out this can cause whistling on certain frequencies due to the aerial tuned circuit not being able to 'reject' unwanted frequencies....so called 'second channel' interference.
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1st Aug 2019, 6:57 pm | #6 |
Dekatron
Join Date: Oct 2003
Location: Croydon, Surrey, UK.
Posts: 7,571
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Re: Bush TR130 208 B/S dead
David was referring to the RF alignment....not the physical alignment or the position of the switch.
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There are lots of brilliant keyboard players and then there is Rick Wakeman..... |
5th Aug 2019, 3:50 pm | #7 |
Octode
Join Date: Dec 2003
Location: Leeds, West Yorkshire, UK.
Posts: 1,592
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Re: Bush TR130 208 B/S dead
Hi. I managed to track down the B/S fault. It turned out to be the wire that connected the switch to capacitors C11 & C12 junction on the circuit board. I gently prodded the wire and it came back to life (although rather briefly). It is probably fractured inside. I have not got any wire that size, but I will look in my box of spares.
cheers Mike |
5th Aug 2019, 4:03 pm | #8 |
Rest in Peace
Join Date: Mar 2011
Location: Basildon, Essex, UK.
Posts: 4,100
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Re: Bush TR130 208 B/S dead
It is unusual for an insulated wire to break inside the insulation, unless it is used as a flexible cord, it is more likely for any wire to break at the soldered connection.
This sounds like you may have found a dirty connection inside the switch and when you prodded the wire it moved the switch connection. Mike |