EKCO RS3, discovered in gran's loft. - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

paulsherwin · 13th Jul 2007, 8:36 pm

A restorer working on a set of this age and rarity would normally try to do a 'museum grade' restoration. This involves fitting modern components inside the shells of the old ones (amongst other things) so the set looks unmodified after leaving the factory.

I appreciate that this is a bit daunting for a beginner, and you will do less harm if you know your limitations and don't try to do too complex a restoration, but you should try to ensure that any changes you make are reversible. Take lots of photos as you work, including closeups of individual components, and save any old components you replace for use by future restorers.

We're all just custodians of these things

Good luck, Paul

chipp1968 · 13th Jul 2007, 9:33 pm

Unless its an updated model i think Nicks probably correct that it may be replacing an original , maybe the one in the box , check the wiring

Mike Phelan · 14th Jul 2007, 8:30 am

I would say it is a capacitor; maybe a later replacement? Does the hole look original?

Interesting to see the Ekco rebadged Rola speaker!

I've popped your picture here for convenience.

'LIVEWIRE?' · 14th Jul 2007, 9:52 am

This model seems to be similar to the SH25, also dating from the 1930s, one of which I repaired back in March 07. The reservoir/Smoothing capacitors in the '25 are in the box, so it's likely that the originals in your R.S.3 are also in the box. Replacement with modern electrolytics under the chassis is probably the best option, removing the cylindrical cap. altogether, but leaving the box(dicsconnected) in situ to preserve the original above-chassis appearance. In the SH25 the original selenium rectifier was also (replaced with a miniature silicon bridge device)

dark_waters · 14th Jul 2007, 1:43 pm

At the risk of sounding a complete amature, whats a Rola speaker?

The electrolytic is rated 8uf and according to my serivce sheet has a maximum rating of 460v Its completely dry and powder comes out the vent holes when you tip it upsidedown.
Im thinking about mounting the new capacitor in the original casing.
RS components has modern day version rated at 10uf and 450v - will this be ok as a replacement? Its a pain the RS make you order a minimum of 5! So if anybody wants any, let me know and i'll post your some for free.

There are a couple of people searching for a replacement valve for me next week......I think i'll change the smoothing capacitors while the case is off too.
The only thing that worries me here is that two of these capacitors are mounted in a case above the transformer and it looks like you need to remove the case by drilling the rivets out? - Nobody panic I havent taken a drill to it just yet!

It amuses me how there is no "slack" in any of the wiring. Its all just about long enough to do the job with no excess.

The case has cleaned up well with only a few marks on it, there is not a crack in sight which is good news.
Nothing looks burnt in the casing, the resistor "look" ok, all the wiring has its insulation on it.

Anyway, the saga continues but its time for lunch......

Darren-UK · 14th Jul 2007, 2:22 pm

Quote:

Originally Posted by dark_waters

At the risk of sounding a complete amature, whats a Rola speaker?

The electrolytic is rated 8uf ........... Im thinking about mounting the new capacitor in the original casing.
RS components has modern day version rated at 10uf and 450v - will this be ok as a replacement?

The only thing that worries me here is that two of these capacitors are mounted in a case above the transformer and it looks like you need to remove the case by drilling the rivets out?

It amuses me how there is no "slack" in any of the wiring. Its all just about long enough to do the job with no excess.

Nothing looks burnt in the casing, the resistor "look" ok, all the wiring has its insulation on it.

Anyway, the saga continues but its time for lunch......

'Rola' is a very common brand of loudspeaker. Your 'Ekco' speaker is, as somebody has said, simply a rebadged Rola. This badge engineering is common and even extends to complete radios by one manufacturer being rebadged to mascurade as a radio by another manufacturer.

The 10uF at 450v will be ok. This will be the modern-day equivalent value and such is what we have to do at times like this; much the same as an old 5uF would be replaced with a modern 4.7 job - to put it in simple terms.

Rivetted components are not unusual ( especially valve sockets ) but, in the case of the can in your Ekco, they may or may not be original. Someone with more knowledge of this radio may be able to confirm. Whatever, if you need access to the can you'll have to remove them carefully. You can replace with pop-rivets ( which is what they will be on your radio ) but nuts and bolts may be prudent at this stage in case you make the mistake of re-rivetting the can only to find a problem occurs inside it later.

Minimal slack in wiring is the norm. This would be done on manufacture for two reasons; 1. To keep components costs to a minimum and 2. Because excess slack in wiring can cause problems with induced hum, stray capacitance......call it what you will.

Resistors will blacken due to overheating, but don't assume they're ok as they appear visually sound. They go out-of-tolerance, often way out. Check 'em with a meter; you'll get a good indictation of their serviceability by checking them in-situ providing nothing else is connected to them in parallel. Otherwise it's a simple matter to disconnect them at one end and then test. Good soldering practice for you too

Good luck with this quite rare survivor.

dark_waters · 25th Jul 2007, 9:11 pm

Ok, so im a virgin at recapping a radio, no doubt most who read this will roll their eyes and think "muppet"

So i've started recapping my Ekco and all is going fairly well. Its all looking fairly neat so far and i've replaced any wiring where the flex has cracked etc. The new surface mount electrolytic is in place, my replacement valve has arrived, i've cleaned up the case and i've wired in all the new caps exactly as the old ones came out.

As always there is a "however"

However ..... whilst I was removing the 2 x paper HT smoothing capacitors from the box above the mains transformer, isolated in wax, numbered C18 & C19 on the scematic, I broke two of the thin wires inside. So, now I dont know which went where?!

There are three terminals on the outside of the box, 2 caps inside the box. Are these caps wired in series, does it matter which wires of the caps go to the terminals on the outside?

School boy error I know...I know... next time i'll be more careful

Station X · 25th Jul 2007, 9:25 pm

C18 and C19 have a common connection which goes to L15. The other ends of these caps go one to each end of L16. Hence only three terminals on the box.

You'll need to check which terminals of the box go where in order to identify the common connection. C18 and C19 have different values, so be sure to connect them to the correct wires in the box. C18 goes to the top of L16 and C19 to the bottom. When I say top and bottom I mean as it appears on the diagram. This may have no relationship whatever to the coils physical position.

dark_waters · 1st Aug 2007, 10:48 am

I've been recapping the EKCO R.S.3. I still havent changed any of the resistors as yet.

So, last night (rather nervously) I plugged it in via a bulb limiter and threw the switch.
Not a lot happened at first and then there was a very very faint faint hum, the valves started to glow and I picked up a radio station

Ok so......as a first timer at this I was quite please with myself......

As a screwdriver as an aerial and powered via the bulb limiter, I picked up a couple of stations on MW.

Just a couple of questions so far...
A. I am worried that you seem to be able to plug the mains lead into the set any way round? Is this normal?!

B. The very faint hum that I hear appears to be from the transformer, is that normal? It doesnt get an louder when tuned to a station is isnt auidable over the speaker.

C. Shall I go right ahead and plug it direct to the mains now?

Steve_P · 1st Aug 2007, 1:15 pm

Yes, for now. It probably has a mains transformer, and I hope fuses. (Some folks used to bridge them out!).

Read here:

http://www.vintage-radio.com/repair-...ly-stages.html

The faint hum is fine. Don't worry about it. If you have done a re-cap, then go on, look round to make sure you haven't missed anything, and try it on full mains...

Cheers,

Steve P

PJL · 1st Aug 2007, 2:47 pm

I have dug out the circuit and as Steve says it has a mains transformer. There are no fuses so make sure you have a 3A one in the plug. I always convert AC sets to 3 core cable and earth the chassis as otherwise an insulation fault in the transformer can make the chassis live.

It's a good idea to monitor the HT volts when you switch it on for the first time. If it doesn't reach the trader sheet value it may be excess current in the output valve (or a weak rectifier).

dark_waters · 1st Aug 2007, 7:23 pm

Plugged her up direct to the mains this evening and now my faint hum as turned into a loud hum. The hum is slightly less on LW but still loud. The loudness of the hum now also changes whilst tuning.

I'm sourcing a tested rectifying valve as my google searching suggests this could be a cause?

Rob.

dark_waters · 1st Aug 2007, 8:02 pm

C18 and C19 have been changed.
C17 has also been changed with a new surface mount bolt through electrolytic.

Hum is still just as loud with the volume down.

I though it was all going to well .... lol

dark_waters · 1st Aug 2007, 8:08 pm

Also - forgot to mention that when its powered through the lamp limiter, the bulb glows very dim which suggests its drawing the correct voltage?

Mersey_Swimmer · 1st Aug 2007, 8:17 pm

Quote:

Originally Posted by dark_waters

Plugged her up direct to the mains this evening and now my faint hum as turned into a loud hum. The hum is slightly less on LW but still loud. The loudness of the hum now also changes whilst tuning.

I'm sourcing a tested rectifying valve as my google searching suggests this could be a cause?

Rob.

Sounds like some of the hum may be modulation hum. C22 (now those two "Y" ceramics) is wired between chassis what should be the live pole of the mains, although this does put the on/off switch in the neutral side. Needless to say any RF diverted from the incoming supply needs to go somewhere so the chassis must be earthed, either to mains earth or (preferably) a good RF earth (water pipe, earth spike, buried metal plate/bin lid etc.)

I didn't realise your set had no fuses, or I'd have packed a couple of 1A plug fuses with your parts. I'll try to get a couple of fuses off to you tomorrow. One of these in your mains plug will prevent anything too serious happening should things go pear-shaped. I'll also pop in a 10uF 350v to replace your HT filter C17 (8uF)

Pete

Steve_P · 1st Aug 2007, 8:19 pm

OK. Right - have you got 270v or so on both the Anodes of V5. Go underneath the set, and you'll see the 4 pins. The two furthest apart ones are the anodes.

If these are OK, then there should be 240v on the Anode of the Output Valve V4. And slightly less on the Screen.

Have you got the circuit by the way?

Cheers,

Steve P

Mersey_Swimmer · 1st Aug 2007, 8:25 pm

Quote:

Originally Posted by Steve_P

Have you got the circuit by the way?

Cheers,

Steve P

It's on Vintage Radio Service Data volume 1.

Pete

Mersey_Swimmer · 1st Aug 2007, 8:50 pm

I'd also suspect the "fixed tone corrector" capacitor C16 (0.004uF) - if it's leaky excess current will be drawn from the HT. To check this simply disconnect it - the radio can be tried without it. I'll add a 4.7n (0.0047uF) 1,000v LCR to the other bits.

Pete

dark_waters · 1st Aug 2007, 9:23 pm

Brilliant

Thank you for all this, its very much appreciated. There cant be much wrong with it (fingers crossed) if its picking up a wealth of stations, the volume control is working with no crackles etc and the sound is good.

I'll double check all my work tomorrow evening, remove C16 and test, clean all the valve holders up and let you know what the score is.

Rob.

dark_waters · 8th Aug 2007, 10:16 am

Thanks Pete - received the package....

Right - I still have to change C16 which I will do tonight...but here is where im at.....
...
I've changed the Rectifier valve for a known good one, double checked everyting, cleaned all the terminals up on the valves, swapped electrolytics over and the radio still hums BUT when its not tuned to a station ......is near as damn it quiet when tuned in

Having said this.. I can receive a lot of stations but they all seem to be slightly out of tune....like the set needs fine tuning....is this down to the fact I havent changed any of the resistors....a couple of them do test a little high?

Finally I tested the DC current off the sets earth plug today........I set the multimeter to 200v DC and it appears to leak around 20v if im reading my multimeter correctly!!??

13th Jul 2007, 8:36 pm	#21
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,957	Re: Ekco Rs3 A restorer working on a set of this age and rarity would normally try to do a 'museum grade' restoration. This involves fitting modern components inside the shells of the old ones (amongst other things) so the set looks unmodified after leaving the factory. I appreciate that this is a bit daunting for a beginner, and you will do less harm if you know your limitations and don't try to do too complex a restoration, but you should try to ensure that any changes you make are reversible. Take lots of photos as you work, including closeups of individual components, and save any old components you replace for use by future restorers. We're all just custodians of these things Good luck, Paul

13th Jul 2007, 9:33 pm	#22
chipp1968 Rest in Peace Join Date: Jul 2006 Location: Somerset, UK. Posts: 2,356	Re: EKCO R.S.3 discovered in grans loft Unless its an updated model i think Nicks probably correct that it may be replacing an original , maybe the one in the box , check the wiring

14th Jul 2007, 8:30 am	#23
Mike Phelan Dekatron Join Date: Nov 2003 Location: Near Leeds, West Yorkshire, UK Posts: 4,609	Re: EKCO R.S.3 discovered in grans loft I would say it is a capacitor; maybe a later replacement? Does the hole look original? Interesting to see the Ekco rebadged Rola speaker! I've popped your picture here for convenience. Attached Thumbnails __________________ Mike.

14th Jul 2007, 9:52 am	#24
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: EKCO R.S.3 discovered in grans loft This model seems to be similar to the SH25, also dating from the 1930s, one of which I repaired back in March 07. The reservoir/Smoothing capacitors in the '25 are in the box, so it's likely that the originals in your R.S.3 are also in the box. Replacement with modern electrolytics under the chassis is probably the best option, removing the cylindrical cap. altogether, but leaving the box(dicsconnected) in situ to preserve the original above-chassis appearance. In the SH25 the original selenium rectifier was also (replaced with a miniature silicon bridge device)

14th Jul 2007, 1:43 pm	#25
dark_waters Retired Dormant Member Join Date: Jul 2007 Location: Bedfordshire Posts: 17	Re: EKCO R.S.3 discovered in grans loft At the risk of sounding a complete amature, whats a Rola speaker? The electrolytic is rated 8uf and according to my serivce sheet has a maximum rating of 460v Its completely dry and powder comes out the vent holes when you tip it upsidedown. Im thinking about mounting the new capacitor in the original casing. RS components has modern day version rated at 10uf and 450v - will this be ok as a replacement? Its a pain the RS make you order a minimum of 5! So if anybody wants any, let me know and i'll post your some for free. There are a couple of people searching for a replacement valve for me next week......I think i'll change the smoothing capacitors while the case is off too. The only thing that worries me here is that two of these capacitors are mounted in a case above the transformer and it looks like you need to remove the case by drilling the rivets out? - Nobody panic I havent taken a drill to it just yet! It amuses me how there is no "slack" in any of the wiring. Its all just about long enough to do the job with no excess. The case has cleaned up well with only a few marks on it, there is not a crack in sight which is good news. Nothing looks burnt in the casing, the resistor "look" ok, all the wiring has its insulation on it. Anyway, the saga continues but its time for lunch......

25th Jul 2007, 9:11 pm	#27
dark_waters Retired Dormant Member Join Date: Jul 2007 Location: Bedfordshire Posts: 17	R.S.3 HT Smoothing Capacitor Ok, so im a virgin at recapping a radio, no doubt most who read this will roll their eyes and think "muppet" So i've started recapping my Ekco and all is going fairly well. Its all looking fairly neat so far and i've replaced any wiring where the flex has cracked etc. The new surface mount electrolytic is in place, my replacement valve has arrived, i've cleaned up the case and i've wired in all the new caps exactly as the old ones came out. As always there is a "however" However ..... whilst I was removing the 2 x paper HT smoothing capacitors from the box above the mains transformer, isolated in wax, numbered C18 & C19 on the scematic, I broke two of the thin wires inside. So, now I dont know which went where?! There are three terminals on the outside of the box, 2 caps inside the box. Are these caps wired in series, does it matter which wires of the caps go to the terminals on the outside? School boy error I know...I know... next time i'll be more careful

25th Jul 2007, 9:25 pm	#28
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,289	Re: R.S.3 HT Smoothing Capacitor C18 and C19 have a common connection which goes to L15. The other ends of these caps go one to each end of L16. Hence only three terminals on the box. You'll need to check which terminals of the box go where in order to identify the common connection. C18 and C19 have different values, so be sure to connect them to the correct wires in the box. C18 goes to the top of L16 and C19 to the bottom. When I say top and bottom I mean as it appears on the diagram. This may have no relationship whatever to the coils physical position. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

1st Aug 2007, 10:48 am	#29
dark_waters Retired Dormant Member Join Date: Jul 2007 Location: Bedfordshire Posts: 17	EKCO What to do next? I've been recapping the EKCO R.S.3. I still havent changed any of the resistors as yet. So, last night (rather nervously) I plugged it in via a bulb limiter and threw the switch. Not a lot happened at first and then there was a very very faint faint hum, the valves started to glow and I picked up a radio station Ok so......as a first timer at this I was quite please with myself...... As a screwdriver as an aerial and powered via the bulb limiter, I picked up a couple of stations on MW. Just a couple of questions so far... A. I am worried that you seem to be able to plug the mains lead into the set any way round? Is this normal?! B. The very faint hum that I hear appears to be from the transformer, is that normal? It doesnt get an louder when tuned to a station is isnt auidable over the speaker. C. Shall I go right ahead and plug it direct to the mains now? Last edited by Darren-UK; 20th Apr 2008 at 9:29 pm. Reason: To suit thread merging

1st Aug 2007, 1:15 pm	#30
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Ekco Rs3 Yes, for now. It probably has a mains transformer, and I hope fuses. (Some folks used to bridge them out!). Read here: http://www.vintage-radio.com/repair-...ly-stages.html The faint hum is fine. Don't worry about it. If you have done a re-cap, then go on, look round to make sure you haven't missed anything, and try it on full mains... Cheers, Steve P __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

1st Aug 2007, 2:47 pm	#31
PJL Dekatron Join Date: Sep 2005 Location: Seaford, East Sussex, UK. Posts: 5,997	Re: Ekco Rs3 I have dug out the circuit and as Steve says it has a mains transformer. There are no fuses so make sure you have a 3A one in the plug. I always convert AC sets to 3 core cable and earth the chassis as otherwise an insulation fault in the transformer can make the chassis live. It's a good idea to monitor the HT volts when you switch it on for the first time. If it doesn't reach the trader sheet value it may be excess current in the output valve (or a weak rectifier).

1st Aug 2007, 7:23 pm	#32
dark_waters Retired Dormant Member Join Date: Jul 2007 Location: Bedfordshire Posts: 17	Re: Ekco Rs3 Plugged her up direct to the mains this evening and now my faint hum as turned into a loud hum. The hum is slightly less on LW but still loud. The loudness of the hum now also changes whilst tuning. I'm sourcing a tested rectifying valve as my google searching suggests this could be a cause? Rob.

1st Aug 2007, 8:02 pm	#33
dark_waters Retired Dormant Member Join Date: Jul 2007 Location: Bedfordshire Posts: 17	Re: Ekco Rs3 C18 and C19 have been changed. C17 has also been changed with a new surface mount bolt through electrolytic. Hum is still just as loud with the volume down. I though it was all going to well .... lol

1st Aug 2007, 8:08 pm	#34
dark_waters Retired Dormant Member Join Date: Jul 2007 Location: Bedfordshire Posts: 17	Re: Ekco Rs3 Also - forgot to mention that when its powered through the lamp limiter, the bulb glows very dim which suggests its drawing the correct voltage?

1st Aug 2007, 8:19 pm	#36
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Ekco Rs3 OK. Right - have you got 270v or so on both the Anodes of V5. Go underneath the set, and you'll see the 4 pins. The two furthest apart ones are the anodes. If these are OK, then there should be 240v on the Anode of the Output Valve V4. And slightly less on the Screen. Have you got the circuit by the way? Cheers, Steve P __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

1st Aug 2007, 8:50 pm	#38
Mersey_Swimmer Retired Dormant Member Join Date: May 2007 Location: Runcorn, Cheshire, UK. Posts: 71	Re: Ekco Rs3 I'd also suspect the "fixed tone corrector" capacitor C16 (0.004uF) - if it's leaky excess current will be drawn from the HT. To check this simply disconnect it - the radio can be tried without it. I'll add a 4.7n (0.0047uF) 1,000v LCR to the other bits. Pete

1st Aug 2007, 9:23 pm	#39
dark_waters Retired Dormant Member Join Date: Jul 2007 Location: Bedfordshire Posts: 17	Re: Ekco Rs3 Brilliant Thank you for all this, its very much appreciated. There cant be much wrong with it (fingers crossed) if its picking up a wealth of stations, the volume control is working with no crackles etc and the sound is good. I'll double check all my work tomorrow evening, remove C16 and test, clean all the valve holders up and let you know what the score is. Rob.

8th Aug 2007, 10:16 am	#40
dark_waters Retired Dormant Member Join Date: Jul 2007 Location: Bedfordshire Posts: 17	Re: Ekco Rs3 Thanks Pete - received the package.... Right - I still have to change C16 which I will do tonight...but here is where im at..... ... I've changed the Rectifier valve for a known good one, double checked everyting, cleaned all the terminals up on the valves, swapped electrolytics over and the radio still hums BUT when its not tuned to a station ......is near as damn it quiet when tuned in Having said this.. I can receive a lot of stations but they all seem to be slightly out of tune....like the set needs fine tuning....is this down to the fact I havent changed any of the resistors....a couple of them do test a little high? Finally I tested the DC current off the sets earth plug today........I set the multimeter to 200v DC and it appears to leak around 20v if im reading my multimeter correctly!!??