UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > Specific Vintage Equipment > Vintage Radio (domestic)

Notices

Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only.

Closed Thread
 
Thread Tools
Old 21st Sep 2018, 11:56 am   #1
marqueemoon
Triode
 
Join Date: May 2014
Location: South Yorkshire, UK.
Posts: 25
Default Vega Selena B215 - capacitor replacement question

Hi folks

Despite already owning one, I couldn't help buying a forlorn-looking Selena from a flea market for a fiver. I got it home, plugged it in and was pleasantly surprised to find that everything worked... except that the FM output was almost non-existent, and only audible with the volume cranked right up.

Reading a few threads (mostly on here) suggests that this could be caused by bad electrolytic capacitors on the board immediately visible when you take the back off. There are five of these, at least one of which looks decidedly unwell on mine (pic attached).

Thing is, I have never seen caps like these. I've successfully replaced the radial type like-for-like in quite a few devices, but an electronics expert I am not! I found (from another post on here!) that K50 means they're aluminium electrolytics, but beyond that...

Can anyone tell me how I work out what the values of these are, and where I can find replacements please?

Cheers!
Attached Thumbnails
Click image for larger version

Name:	selena cap.jpg
Views:	544
Size:	38.3 KB
ID:	169640  
marqueemoon is offline  
Old 21st Sep 2018, 1:07 pm   #2
FIXITNOW
Octode
 
FIXITNOW's Avatar
 
Join Date: Feb 2007
Location: Ely, Cambridgeshire, UK.
Posts: 1,967
Default Re: Vega Selena B215 - capacitor replacement question

these another thread that may help sorry do not have time to read it all
vince
https://www.vintage-radio.net/forum/...d.php?t=122760
FIXITNOW is online now  
Old 21st Sep 2018, 2:15 pm   #3
orbanp1
Heptode
 
Join Date: Nov 2009
Location: London, Ontario, Canada
Posts: 672
Default Re: Vega Selena B215 - capacitor replacement question

That looks like a 20uF 12V electrolytic cap.
A 22uF 16V cap should do there fine.

Peter
orbanp1 is offline  
Old 21st Sep 2018, 8:54 pm   #4
julie_m
Dekatron
 
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
Default Re: Vega Selena B215 - capacitor replacement question

The Russian letter В is a Latin V, and a Russian Ф is a Latin F. So it's a 12V, 20μF capacitor. The nearest modern equivalent would be 16V, 22μF; and a modern capacitor probably will have both leads coming out of the same end, and be physically smaller -- by up to half -- than an old one.

Electrolytic capacitors are polarity sensitive, and must be connected with the positive and negative leads the right way around. Other capacitors (low values, below 1μF) are not polarity-sensitive. Some may be marked with a band denoting the outer foil; if you replace one such and get problems later such as power hum or instability, try reversing the connections to the replacement capacitor.

Capacitors are responsible for a lot of faults with old radios, and replacing them will almost always yield an improvement. The worst case economically is when you replaced all the capacitors in a set but only one was faulty -- all but one of the set's capacitors will have been replaced needlessly! Also, there is a risk of damaging the printed circuit board when using a soldering iron.

Take your time; take plenty of pictures of the set in various stages of undress, so you can be sure of putting it all back together at the end; and test the set after replacing each capacitor -- if you have mis-wired something, it's much better to find out about it straight away, so you don't have to spend even more time searching for a new fault that you introduced.
__________________
If I have seen further than others, it is because I was standing on a pile of failed experiments.
julie_m is offline  
Old 23rd Sep 2018, 7:47 pm   #5
marqueemoon
Triode
 
Join Date: May 2014
Location: South Yorkshire, UK.
Posts: 25
Default Re: Vega Selena B215 - capacitor replacement question

Thanks for this. Based on the above, the other 4 caps are:

12V 50μF
12V 5μF
12V 10μF
6.3V 50μF

Do these also have modern equivalents that I should be looking for?

Thanks again.
marqueemoon is offline  
Old 23rd Sep 2018, 9:17 pm   #6
Freya
Octode
 
Freya's Avatar
 
Join Date: Jan 2009
Location: Falmouth, Cornwall, UK.
Posts: 1,987
Default Re: Vega Selena B215 - capacitor replacement question

In your list order they would be
47uF 16v
4.7uF 16v
10uF 16v
47uF 10v (can get lower voltage but not worth it)
the capacitor in your picture is an axial style with the leads exiting from either end, you can also get radial where they both exit from the same end.
__________________
Stephen
_________"It`s only an old telly" ___
Freya is online now  
Old 24th Sep 2018, 9:49 am   #7
Herald1360
Dekatron
 
Herald1360's Avatar
 
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,526
Default Re: Vega Selena B215 - capacitor replacement question

It won't matter if you go up to maybe 50v rating on these caps if that makes suitable values easier to find / more like the originals in size.
__________________
....__________
....|____||__|__\_____
.=.| _---\__|__|_---_|.
.........O..Chris....O
Herald1360 is offline  
Old 24th Sep 2018, 7:55 pm   #8
marqueemoon
Triode
 
Join Date: May 2014
Location: South Yorkshire, UK.
Posts: 25
Default Re: Vega Selena B215 - capacitor replacement question

Fantastic, thanks. I will do some shopping and let you know how I get on!
marqueemoon is offline  
Old 27th Sep 2018, 6:27 pm   #9
marqueemoon
Triode
 
Join Date: May 2014
Location: South Yorkshire, UK.
Posts: 25
Default Re: Vega Selena B215 - capacitor replacement question

Well, it was a far more fiddly job than I've tried before, but it's done. It came out of the case easily enough, but I had to disconnect the wires from the board that go to the FM tuner so that I could access the underside of the board to de-solder the old Russian caps.

Unscrewing the battery holder helped too, and then there was the metal shield soldered to the bottom of the board that I had to remove to get at two of the offending capacitors. Tricky stuff by my standards!

The bad news is that FM is still very faint. The good news is that I didn't break the radio, and it's now got five less leaking caps than it had this morning. It seems louder on SW now, though, although I couldn't swear to that.

Any thoughts on what I might try next to see if I can get FM up and running?
marqueemoon is offline  
Old 27th Sep 2018, 7:48 pm   #10
Freya
Octode
 
Freya's Avatar
 
Join Date: Jan 2009
Location: Falmouth, Cornwall, UK.
Posts: 1,987
Default Re: Vega Selena B215 - capacitor replacement question

This link may be useful to your repair,
https://www.petervis.com/Radios/sele...m-circuit.html
__________________
Stephen
_________"It`s only an old telly" ___
Freya is online now  
Old 27th Sep 2018, 10:54 pm   #11
ronbryan
Octode
 
Join Date: Jan 2003
Location: Guildford, Surrey, UK.
Posts: 1,958
Default Re: Vega Selena B215 - capacitor replacement question

Poor FM on the B215 is often caused by faulty coupling and/or tuning capacitors in the FM IF band pass filter. I believe they are all ceramic types.

Ron
ronbryan is online now  
Old 28th Sep 2018, 7:38 pm   #12
ursus6267
Diode
 
Join Date: Sep 2018
Location: Minsk, Belarus.
Posts: 1
Default Re: Vega Selena B215 - capacitor replacement question

This link may be useful to your repair https://0jihad0.livejournal.com/2662.html
ursus6267 is offline  
Old 29th Sep 2018, 5:16 pm   #13
Andrewausfa
Octode
 
Andrewausfa's Avatar
 
Join Date: Dec 2010
Location: St Ives, Cambridgeshire, UK.
Posts: 1,180
Default Re: Vega Selena B215 - capacitor replacement question

The only (?) internet schematic on the 215 seems to be the 216 version. If you wondered why, this is the Vega issued Selena 215 circuit which comes on a large bit of paper printed both sides. Likely the reason is the difficulty in scanning it. With the 215-217 instruction booklet and a D cell for comparison.

Andrew
Attached Thumbnails
Click image for larger version

Name:	IMG_0005.jpg
Views:	228
Size:	91.6 KB
ID:	170044  
__________________
Invisible airwaves crackle with life. Or they should do.
BVWS Member
Andrewausfa is offline  
Old 30th Sep 2018, 10:49 am   #14
Radiocruncher
Hexode
 
Radiocruncher's Avatar
 
Join Date: Dec 2013
Location: Torrington, Devon UK.
Posts: 445
Default Re: Vega Selena B215 - capacitor replacement question

That’s a great document to own Andrew. I’m sure the 216 is identical except for the FM coverage. If you ever want that scanned just drop me a message and I will do it for you.

Regards

Graham

P.S. I wouldn’t mind a good copy of that for myself.
Radiocruncher is offline  
Old 27th Oct 2018, 2:14 pm   #15
marqueemoon
Triode
 
Join Date: May 2014
Location: South Yorkshire, UK.
Posts: 25
Default Re: Vega Selena B215 - capacitor replacement question

So... I'm looking at the schematic for the HF-IF Unit, but the values for the capacitors shown there appear to be given without units? For example C5 is just shown as 51, C15 as 33 etc. I'm guessing there's a default unit, but I don't know what that is. Any ideas please?
marqueemoon is offline  
Old 27th Oct 2018, 5:01 pm   #16
ronbryan
Octode
 
Join Date: Jan 2003
Location: Guildford, Surrey, UK.
Posts: 1,958
Default Re: Vega Selena B215 - capacitor replacement question

For those capacitors on the HF-IF unit the default is pF.

Ron

Last edited by ronbryan; 27th Oct 2018 at 5:10 pm.
ronbryan is online now  
Old 27th Oct 2018, 8:53 pm   #17
Maarten
Dekatron
 
Join Date: Dec 2007
Location: Haarlem, Netherlands
Posts: 4,184
Default Re: Vega Selena B215 - capacitor replacement question

Usually they will still be good (either ceramic or mica) so not in need of replacement. Also, replacing such capacitors could result in the need for a full alignment.
Maarten is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 4:53 pm.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.