|
Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
|
Thread Tools |
18th Dec 2017, 11:34 am | #1 |
Hexode
Join Date: Nov 2005
Location: Kent, UK.
Posts: 332
|
Sharp Transistor 10 BXS-330 radio help please
Hi everyone,
I have a vintage Sharp Transistor 10 BXS-330 that belonged to my dad and for many years this Radio was neglected as it didn’t work. I would like to get it back to work and I have some questions please. Firstly this uses the following germanium transistors: 2SA80, 2SA82, 2SB74, 2SA14, 2SA12, 2SB75, 2SB156 I have not tested anything yet but the radio is totally dead. I suspect the output transistors have failed (2SB156). I would like to replace all 10 transistors with equivalent silicon ones. Anyone knows please what the modern equivalents are to the above mentioned transistors? I would also replace all electrolytics too. Finally, there’s are very unusual socket that serves as ac in which is an in between a 3.5 mm and a 6.3 mm jack. Any ideas what size of plug this socket takes please? Many thanks |
18th Dec 2017, 11:45 am | #2 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,936
|
Re: Sharp Transistor 10 BXS-330 radio help please
I would strongly advise against replacing all the transistors with silicon as this is unlikely to be straightforward. In fact I wouldn't even replace them with Ge equivalents unless they're actually faulty. Why do you think there are transistor problems? Japanese Ge transistors aren't known for faults.
It's much more likely that the failure to operate is down to switch contact problems or bad electrolytics. Time for some systematic fault finding. |
18th Dec 2017, 11:46 am | #3 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,287
|
Re: Sharp Transistor 10 BXS-330 radio help please
Hello and welcome to the forums.
Please don't replace transistors or other components just because you think they might be faulty. That's a recipe for disaster. Have you considered that the problem might just be dirty contacts on the earphone jack or AC adaptor jack? Check the simple things first. If no joy you'll need to take voltage readings, start round the output transistors. Post the results here and someone will advise you.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
18th Dec 2017, 11:47 am | #4 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,287
|
Re: Sharp Transistor 10 BXS-330 radio help please
Posts crossed, but we're singing from the same hymn sheet.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
18th Dec 2017, 12:40 pm | #5 |
Hexode
Join Date: Nov 2005
Location: Kent, UK.
Posts: 332
|
Re: Sharp Transistor 10 BXS-330 radio help please
Hi, thanks for the advice. I shall of course check for faults before replacing stuff but I’ had bad experience with a Uher 4000 with bad transistors and therefore I’m presuming it’s them in this case. Electrolytics will be tested for high esr of course. I shall do the basic fault finding first such as faulty speaker, switch contacts, although I have already shot them with contact cleaner. I don’t want to replace anything that might throw the alignment out. I suspect a problem in the amplifier section however. It hasn’t been used for probably 30 years! No sign of life. Any news on the ac adapter jack please? Where can I find such a thing? I only tried to power it up using crocodile clips connected to the batter terminals feeding 6v dc.
Thanks for all your help so far |
18th Dec 2017, 12:55 pm | #6 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,553
|
Re: Sharp Transistor 10 BXS-330 radio help please
I would go for that external AC adapter socket first.. Make connections where the wires go to the PCB. We all know how much trouble adapter sockets are like as they still can't get them reliable on modern laptops and phones.
The ear phone socket will have to be next. You need a meter with a continuity beeper at least to test the basic electrics. Do remember that it is a positive earth set and that all voltages are measured with one lead on the positive terminal of the battery. |
18th Dec 2017, 5:07 pm | #7 |
Rest in Peace
Join Date: Apr 2011
Location: Matlock, Derbyshire, UK.
Posts: 1,378
|
Re: Sharp Transistor 10 BXS-330 radio help please
I am a strong believer in getting the DC conditions correct first. Measure the voltage of the emitter, base and collector of all transistors. There should be about 0.2V between base and emitter. I would expect 10 to 20mA set consumption.
The AC adaptor is not AC, it is a 6V DC supply as you have used. |
18th Dec 2017, 7:39 pm | #8 | |
Nonode
Join Date: Jan 2008
Location: Milton Keynes, Bucks. UK.
Posts: 2,552
|
Re: Sharp Transistor 10 BXS-330 radio help please
JASCHA,
Quote:
It's not like the common 3.5mm & 6.3mm of today which are usually used for audio input or output, the socket on the Sharp is insulated and (as far as I can recall),1 side of the connectors is connected to the chassis. Here's a pic of my model
__________________
When I die, please don't let my Wife sell my collection for the amount I told her I paid for it! Last edited by camtechman; 18th Dec 2017 at 7:46 pm. |
|
18th Dec 2017, 8:18 pm | #9 |
Nonode
Join Date: Jan 2008
Location: Milton Keynes, Bucks. UK.
Posts: 2,552
|
Re: Sharp Transistor 10 BXS-330 radio help please
JASCHA,
To follow on, here's the link to my original thread, when I enquired about the very same Sharp 4.0mm plug problem 5 years ago and NOTE, it turned out to be 4.5 mm !! https://www.vintage-radio.net/forum/...=sharp+BXG+370
__________________
When I die, please don't let my Wife sell my collection for the amount I told her I paid for it! Last edited by camtechman; 18th Dec 2017 at 8:24 pm. |
18th Dec 2017, 9:18 pm | #10 | |
Triode
Join Date: Dec 2017
Location: East Prawle, Devon, UK.
Posts: 37
|
Re: Sharp Transistor 10 BXS-330 radio help please
Quote:
2SA80 and 2SA82 EQ is AF124 AF126 AF200 2SA218 2SA227 2SA12 and 2SA14 EQ is AF124 AF127 AF200 2SA201 2SA203 2SB74 EQ is AC125 AC126 AC151 2SB54 2SB56 2SB75 EQ is AC125 AC126 AC151 2SB54 2SB56 2SB156 EQ is AC128 AC153 AC188 2sb405 2SB475 They were germanium for a reason keep them that way My 2 penneth over Andy
__________________
Thanks for All 73's Andy G0JIA |
|
18th Dec 2017, 10:53 pm | #11 |
Nonode
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
Posts: 2,350
|
Re: Sharp Transistor 10 BXS-330 radio help please
Interesting to note on the Circuit Diagram, it is SHARPE, not SHARP. When did that change. A bit like To Shiba becoming Toshiba, Lucky Goldstar becoming LG, and others.
Les. |
19th Dec 2017, 1:22 am | #12 |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,711
|
Re: Sharp Transistor 10 BXS-330 radio help please
And National Panasonic.
I don' think there is any significance in the "E" at the end of Sharp other than a typo. I think the circuit in the screenshot came from http://www.kevinchant.com A random dip into the the Sharp circuits held there brought up this one with SHARP and SHARPE on the same page. http://www.kevinchant.com/uploads/7/...222_tr-223.pdf
__________________
-- Graham. G3ZVT Last edited by Graham G3ZVT; 19th Dec 2017 at 1:37 am. |
19th Dec 2017, 1:32 am | #13 | |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,535
|
Re: Sharp Transistor 10 BXS-330 radio help please
Quote:
The reason to keep them that way is because it's a lot simpler than redesigning and modifying the set!
__________________
....__________ ....|____||__|__\_____ .=.| _---\__|__|_---_|. .........O..Chris....O |
|
19th Dec 2017, 10:16 am | #14 |
Nonode
Join Date: Jan 2004
Location: 1966-1976 Coverack in Cornwall and Helston Cornwall. 1976-present Bristol/Bath area.
Posts: 2,965
|
Re: Sharp Transistor 10 BXS-330 radio help please
Just like to back everyone up here. These are nice solid little radios with a good circuit.
If it is completely dead the first suspects will be the switch contacts of the on-off switch, and the switch contacts on the back of the dc input socket and headphone socket. If these are ok some voltage checks will soon lead you to the fault.
__________________
Simon BVWS member |
19th Dec 2017, 11:36 am | #15 |
Hexode
Join Date: Nov 2005
Location: Kent, UK.
Posts: 332
|
Re: Sharp Transistor 10 BXS-330 radio help please
Thank you all so much. These forums are wonderful and to know there’s so much support. It will be some days to go till I can have a look properly at the radio due to work however but will update as I go along. I haven’t taken it apart yet but wanted to post my questions straight away. I understand that GE transistors tend to be noisy hence my thoughts about replacing them? I also noted that one black cable attached to the internal aerial has come unsolderered from the circuit board and have no idea where it should go! That’s going to be a pain to trace! I doubt I can find an input dc jack that’s around 5mm in diameter? Any ideas or tips please?
I shall check the switch contacts again and do some basic testing. As long as the two ning section is all fine I should be able to get it going hopefully. Thanks for the equivalents Andy Cheers |
19th Dec 2017, 11:50 am | #16 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,936
|
Re: Sharp Transistor 10 BXS-330 radio help please
Ge transistors are poorer performers than Si in most respects, but you can't simply swap them over without circuit changes. The radio will be fine with the original Ge types if they are working properly.
|
19th Dec 2017, 11:56 am | #17 |
Hexode
Join Date: Nov 2005
Location: Kent, UK.
Posts: 332
|
Re: Sharp Transistor 10 BXS-330 radio help please
I just hope they will test ok as it will save a lot of hassle. The caps however must have by now dried up and no harm done to replace the dodgy ones. I look forward to get it back to work. It does need btw an antenna as the original one mostly vanished and all there is left is the metal housing of the original. Where can I find a suitable replacement for it please? Maplins? Cricklewood El?
Cheers |
19th Dec 2017, 12:01 pm | #18 |
Moderator
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,936
|
Re: Sharp Transistor 10 BXS-330 radio help please
It will almost certainly use a ferrite rod for MW so you only need a telescopic aerial for SW. You will need to measure the dimensions of the original and try to find something that matches - a forum member may be able to help. The telescopic rods used in Poundland TV aerials can be suitable in some cases.
|
19th Dec 2017, 12:29 pm | #19 | |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,287
|
Re: Sharp Transistor 10 BXS-330 radio help please
Quote:
Please leave the caps alone until you done some basic testing. Once the radio is working you can change them ONE AT A TIME.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
|
19th Dec 2017, 12:55 pm | #20 | |
Nonode
Join Date: Jan 2008
Location: Milton Keynes, Bucks. UK.
Posts: 2,552
|
Re: Sharp Transistor 10 BXS-330 radio help please
Quote:
The particular type of telescopic aerial for this radio has a threaded bolt at the bottom end which screws in to socket at the rear R/H of the radio. See marked up pics (yellow circle) and further pic of my radio with the aerial located.
__________________
When I die, please don't let my Wife sell my collection for the amount I told her I paid for it! |
|