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Vintage Audio (record players, hi-fi etc) Amplifiers, speakers, gramophones and other audio equipment. |
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13th Jan 2018, 6:27 pm | #1 |
Heptode
Join Date: Mar 2014
Location: Leeds, West Yorkshire, UK.
Posts: 902
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Bush SRP 51
Picked this up the other day mainly to stop it being thrown away. Its previous owner told me it didn't work, been messing around with it today and so far have cleaned and lubed the Garrard deck. It's now working well and so is the Sonotone cart. The amplifier was totally dead so after doing a few voltage checks I found this [photo ] BC119 transistor leg snapped off. With the thing powered up I touched the lead back on its stump and the thing burst into life so although the transistor is working I cant see any way of repairing it. I suppose it will have to be replaced unless you guys know different?
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13th Jan 2018, 7:59 pm | #2 |
Moderator
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Re: Bush SRP 51
It's impossible to tell from your picture whether there's enough of the transistors lead left to solder to. There's no harm in trying though and you've nothing to lose by trying. Perhaps dig out part of the transistor base (I don't mean the electrode name) to gain expose more lead?
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
13th Jan 2018, 8:28 pm | #3 |
Heptode
Join Date: Mar 2014
Location: Leeds, West Yorkshire, UK.
Posts: 902
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Re: Bush SRP 51
Here's a better photo. As you can see there's just not enough lead left to solder on to. I think I might have to replace the transistor assuming they are available.
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13th Jan 2018, 8:30 pm | #4 |
Heptode
Join Date: Mar 2016
Location: Essex, UK.
Posts: 602
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Re: Bush SRP 51
A BFY50/51/52 is a suitable replacement, though that transistor could be repaired with careful soldering. Also make sure the output transistor bias variable resistor is set between 18 to 20 Ohms, the unreliable open variable pot can be replaced by a close tolerance fixed resistor, if the pot is set to high the output transistors will overheat due to too much base bias current. A good record player.
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Geoff |
13th Jan 2018, 8:33 pm | #5 |
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Re: Bush SRP 51
There's plenty left to solder to there. Use a small bit and be sure not to short the lead to the base with solder.
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
13th Jan 2018, 9:53 pm | #6 |
Heptode
Join Date: Mar 2014
Location: Leeds, West Yorkshire, UK.
Posts: 902
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Re: Bush SRP 51
It's been on for around two hours now [with the wire just touching the transistor] and the output transistors are what I would call just warm, definitely not hot. I will attempt to solder the wire tomorrow [wish me luck].
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13th Jan 2018, 11:01 pm | #7 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,553
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Re: Bush SRP 51
I would after soldering add a little spot of epoxy to the connection to give it a bit more strength.
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14th Jan 2018, 11:22 pm | #8 |
Heptode
Join Date: Mar 2014
Location: Leeds, West Yorkshire, UK.
Posts: 902
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Re: Bush SRP 51
well i have tried [unsuccessfully]to solder the lead back on .there just isn't enough to get a good fix so i have given up and bought a new transistor [just waiting for it to arrive
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16th Jan 2018, 8:02 pm | #9 |
Heptode
Join Date: Mar 2014
Location: Leeds, West Yorkshire, UK.
Posts: 902
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Re: Bush SRP 51
fitted the new transistor today and its now working well .I left the amp on for a couple of hours and i am happy to say there appears to be no problems with it .nothing getting hot .The output transistors are just warm .Thanks everyone for the usual first class advice
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17th Jan 2018, 12:14 am | #10 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,553
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Re: Bush SRP 51
Well done.
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19th Jan 2018, 11:13 pm | #11 |
Heptode
Join Date: Mar 2014
Location: Leeds, West Yorkshire, UK.
Posts: 902
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Re: Bush SRP 51
Not quite finished yet guys. The machine is working well and sounds really good. Only problem left to solve is the Garrard 3500 deck. Can anyone tell me how to adjust the set down point for the arm. The thing goes through the cycle perfectly, it just lowers the arm too far in.
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20th Jan 2018, 1:03 am | #12 |
Heptode
Join Date: Jul 2012
Location: Derby DE1, Derbyshire, UK.
Posts: 626
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Re: Bush SRP 51
Hi,
There may be a small screw somewhere at the back underneath where the arm is pivoted, it will only require a slight turn to adjust it. You will know if you have turned it in the correct direction, by trial and error. Of course with not being familiar with this particular turntable, I'm not sure if that is the layout, others may well be better positioned to advise you, but i just thought my suggestion may give you an idea where to look. Paul. |
20th Jan 2018, 9:08 pm | #13 |
Heptode
Join Date: Mar 2014
Location: Leeds, West Yorkshire, UK.
Posts: 902
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Re: Bush SRP 51
I have looked and better looked, but still can't find anything that might move the arm in or out.
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20th Jan 2018, 9:18 pm | #14 |
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Re: Bush SRP 51
According to the service sheet, this player is fitted with a Garrard 3500 record deck.
You can download the service manual for the deck here:- https://www.vinylengine.com/library/garrard/3500.shtml
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Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
20th Jan 2018, 9:31 pm | #15 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
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Re: Bush SRP 51
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20th Jan 2018, 9:51 pm | #16 |
Heptode
Join Date: Mar 2014
Location: Leeds, West Yorkshire, UK.
Posts: 902
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Re: Bush SRP 51
thats it adjusted screw D and its now setting down at the right position thank you so much .Note screw D it tiny and can barely be seen unless you have a good light and a magnifying glass .Thanks again guys for your help
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