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Old 13th May 2021, 12:00 pm   #1
Dorian27
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Default Stella ST154U. (Actually a Ferranti U1033).

Can you help please. Am I correct in assuming that the capacitor in the picture is the coupling capacitor on this Stella radio. What replacement would I need if it is please if any one could direct me please. Thank you
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Old 13th May 2021, 1:36 pm   #2
ms660
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Default Stella ST154U. (Actually a Ferranti U1033).

Is the model number correct?

Lawrence.
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Old 13th May 2021, 2:02 pm   #3
cathoderay57
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Default Stella ST154U. (Actually a Ferranti U1033).

If you get the service data here https://www.service-data.com/search....&search=Search there are helpful pictures that show you where each component is located on the chassis. To answer your question it appears to me that the tubular aluminium capacitor with axial leads covered in a polythene sheath in the centre of the image, marked 0.01uF 350v DC, is indeed the AF coupling capacitor listed in all the service sheets as C49 (originally a ceramic type). From your photo, one end of it appears to be connected to the UABC80 triode anode (pin 9) in accordance with the circuit. The circuit shows that the other end ought to be connected via a 1k resistor (R26) to the UL84 grid 1 (pin 2), but in your image it looks like the resistor is missing and the capacitor is connected directly to UL84 pin 2. Also that same end of C49 should have a 470k resistor (R25) connected to chassis but in your photo it looks like 1M. Finally I can see the base of a large aluminium can electrolytic with 4 solder tags on it which doesn't match up to anything in the circuit. If it is the main HT capacitor (seems likely) then it's in the wrong place compared to the service data - should be C1/C2 at the other end of the chassis. Seems like an oddity that has had a number of previous repairs! You ought to be able to source components fairly easily when you can read the value? Cheers, Jerry.
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Old 13th May 2021, 2:44 pm   #4
dazzlevision
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Default Stella ST154U. (Actually a Ferranti U1033).

The photo looks to be from an Ekco radio - U354 perhaps..?
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Old 13th May 2021, 4:45 pm   #5
Dorian27
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Default Stella ST154U. (Actually a Ferranti U1033).

I have taken more photos of the radio. The photo of the resistor I am pointing to this get really hot I don't know if it should. I have left radio on for 20min and seems to work OK with lovely sound. It is because of the resistor getting hot I thought it might be the coupling capacitor. Work has been done before I purchase it. The big cap with 4 terminals is RED40uf YELLOW 40uf GREEN 32uf 300VDC WKG. CAN ANY ONE TELL ME IF IT IS THE COUPLING CAPACITOR WHAT VALUE AND VOLT SHOULD THE REPLACEMENT BE PLEASE
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Old 13th May 2021, 4:56 pm   #6
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Default Stella ST154U. (Actually a Ferranti U1033).

The only way I can answer your question is by looking at the service sheet. Do you have the service sheet?

The circuit in the Trader service sheet shows that the audio coupling capacitor is C49 and the chassis layout diagram shows it's located close to the valve holder for V5. The parts list shows its value as 0.01uF. If there's no voltage rating on the existing component I'd go for something rated at 250VDC or more.

EDIT. I see that this information and more has already been given in post #3.
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Old 13th May 2021, 6:27 pm   #7
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Default Stella ST154U. (Actually a Ferranti U1033).

Quote:
Originally Posted by Dorian27 View Post
I have taken more photos of the radio. The photo of the resistor I am pointing to this get really hot I don't know if it should.
That resistor is part of the cathode bias circuit, it would normally be dissipating approx. 0.5 Watts if the resistor is per spec, not sure if what looks to be some cathode stabilizing resistors are the correct value (the two replacement ones connected in parallel) a check with the schematic should tell you.

Lawrence.
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Old 13th May 2021, 6:44 pm   #8
Dorian27
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Default Stella ST154U. (Actually a Ferranti U1033).

Hi Lawrence all I can tell you the colour code on the resistor is or looks like is BROWN GREEN BROWN SILVER. I'd like to thank all of you for help. The capacitor is the value stated 0.01uf 350v dc. All I want to now is what I should replace it with in uf or nf and volts not sure what type myself.
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Old 13th May 2021, 6:54 pm   #9
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Default Stella ST154U. (Actually a Ferranti U1033).

Quote:
Originally Posted by Dorian27 View Post
Hi Lawrence all I can tell you the colour code on the resistor is or looks like is BROWN GREEN BROWN SILVER. I'd like to thank all of you for help. The capacitor is the value stated 0.01uf 350v dc. All I want to now is what I should replace it with in uf or nf and volts not sure what type myself.
150 Ohms would tally up with the EKCO schematic (as does the 33 Ohm resistor that's in series with it), I would check the actual values as they might have changed.

This capacitor will do:

https://www.cricklewoodelectronics.com/CFH10NH.html

Other suppliers are available.

Lawrence.
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Old 13th May 2021, 7:30 pm   #10
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Default Stella ST154U. (Actually a Ferranti U1033).

The edit window time ran out for my previous post.....Should have also mentioned that if the cathode current is too high the filament voltage for the tuning indicator is also likely to be high, these tuning indicator filaments don't like it up 'em.

Lawrence.
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Old 13th May 2021, 7:56 pm   #11
Dorian27
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Default Stella ST154U. (Actually a Ferranti U1033).

Sorry sorry I got this all wrong it is not a stellar at all this is a Ferranti U1032. Model I think I need shooting.
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Old 13th May 2021, 8:05 pm   #12
ms660
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Default Stella ST154U. (Actually a Ferranti U1033).

We knew it wasn't the Stella.

The chassis looks different to a Ferranti U1032 I'm looking at.

A U1033 might fit the bill.

Lawrence.

Last edited by ms660; 13th May 2021 at 8:23 pm. Reason: extra info
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Old 13th May 2021, 8:41 pm   #13
dazzlevision
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Default Stella ST154U. (Actually a Ferranti U1033).

The chassis pictured is VHF/FM only, so it is a Ferranti U1033, the equivalent model to an Ekco U354.
I have recently restored one of each - it’s only the cabinet, tuning scale, back cover and knobs that are different.
I wouldn’t run the radio until you have replaced that “TCC Metalmite” 0.01uF/350V capacitor (the one in a small cylindrical aluminium case with clear plastic sleeving over it). It’s likely to be the cause of that 150 Ohm resistor cooking.

Last edited by dazzlevision; 13th May 2021 at 8:54 pm.
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Old 13th May 2021, 9:04 pm   #14
Dorian27
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Default Stella ST154U. (Actually a Ferranti U1033).

I will take a picture of the radio tomorrow it looks like the Ecko u354 but a bit taller in size puy. Thanks for all help sorry I got it wrong
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Old 14th May 2021, 10:46 am   #15
Dorian27
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Default Stella ST154U. (Actually a Ferranti U1033).

This is a picture of the radio
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Old 14th May 2021, 10:51 am   #16
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Default Stella ST154U. (Actually a Ferranti U1033).

https://www.radiomuseum.org/r/ferranti_u1033u_103.html

The info is wrong in as much as it gives the IF as 470kHz rather than 10.7MHz.

Does your set have the model number on the back panel?
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Old 14th May 2021, 11:08 am   #17
Dorian27
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Default Stella ST154U. (Actually a Ferranti U1033).

No nothing on the back as the back cover was missing I had to make one for it
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Old 14th May 2021, 11:18 am   #18
dazzlevision
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Default Re: Stella ST154U. (Actually a Ferranti U1033).

It’s a Ferranti U1033 (I have one); electrically identical to an Ekco U354.

Perhaps the Mods could change the title of this thread?
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Old 14th May 2021, 1:51 pm   #19
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Default Stella ST154U. (Actually a Ferranti U1033).

OK. The OP was asked in post #2 if the model number was correct, but didn't reply.

Turns out both the make and model were incorrect, even thought the make is clearly visible on the cabinet. A lot of members' time has been needlessly wasted.

19 post titles updated.
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Old 14th May 2021, 4:33 pm   #20
Dorian27
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Default Re: Stella ST154U. (Actually a Ferranti U1033).

I do appologise for this incorrect info and wasting time please forgive the inconvenience as I said I am a novice and I have made a lot of mistakes this week apologies .a

I do apologise for this trouble and inconvenience. I have made a lot of mistakes this week I don't now why please accept my apologies.
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