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Old 25th Jan 2019, 7:09 pm   #141
JulietMike
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Default Re: Trio 9R-59D receiver problems.

Here is a photo showing three replacement capacitors fitted inside a Trio 9R59DS.
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Old 25th Jan 2019, 8:08 pm   #142
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Default Re: Trio 9R-59D receiver problems.

Juliet Mike it did come to my mind about that .All three replaced at he same time yes.But i have obstructions in front , on my set .
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Old 25th Jan 2019, 8:20 pm   #143
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Default Re: Trio 9R-59D receiver problems.

About to order three more only radial Cricklwood is brilliant and fast delivery . But looking i see the same value 47uf 450 volts 105 c for the radil type is there any other value i have missed .
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Old 25th Jan 2019, 10:20 pm   #144
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Default Re: Trio 9R-59D receiver problems.

Quote:
Originally Posted by Humptydumpty View Post
I wont be able to fit them in a can either .
Trev - You don't want to be fitting them inside the can!

You don't want to attempt re-stuffing an electrolytic capacitor can unless you're very experienced.

I don't believe in re-stuffing that sort of capacitor anyway. Many do and make a fantastic looking job, but the sets that get restored in this way often don't get the 24/7 use like they may have done when in their earlier years. Electrolytic capacitors have a temperature rating printed on them and rely on the natural air surrounding the case for cooling, particularly when a bit of ripple current is involved - they were never designed to be wrapped in cardboard and shoved inside another metal can. In years to come, how will anyone know whether there's a problem with the capacitor if it's hidden inside another can? None of us have lived (or probably will live) long enough to know how these encased electrolytics will react after a few decades. I'm not saying that I would never re-stuff, but for a set in regular use I prefer a good, honest historical repair, with capacitors replaced under the chassis. If the set's going to be a museum piece getting occasional use, then re-stuffing is good. However, there's already been documented cases where someone has started to clip out capacitors for replacement, only to find that there's already replacements inside the old capacitor cases, so just causes confusion for the future. It's a subject that folks will argue over till the cows come home, so it's entirely up to the individual how they go about a repair/restoration in this way, but something to think about.

You've now got a small stock of three useful capacitors for testing/substitution. There's no reason why you can't fit all three of those capacitors under the chassis with a bit of thought and manipulation. If you take time out to look further on the Cricklewood site, you'll see that they do a two in one can capacitor similar to your existing one, I think it's 50+50@500 volts), go and check it out! You could fit one like that in place of the two smoothing sections, just using one of the single ones you've already bought to replace the reservoir section, as they have a good ripple rating for this purpose.

Lastly, looking at one of your last pictures, I gather that it's the output transformer that I can see that you've now mounted beneath the chassis. Have you checked that there's no AC wiring running behind it that may be inducing hum? Where does the brown live wire from that replacement mains lead run? What about AC valve heater wiring? Is it located very close to that transformer? It's quite likely that it isn't inducing any hum, but you need to think about this sort of thing and find out! Unbolt the transformer and move it out of the way and see what happens, turn it at an angle while listening, but be very careful to avoid electric shock while working on it live!
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Old 25th Jan 2019, 11:20 pm   #145
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Default Re: Trio 9R-59D receiver problems.

Trevor,

It seems that the new location for the output transformer is causing the obstruction which is preventing you from fitting the capacitors below the chassis.

John
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Old 26th Jan 2019, 10:32 am   #146
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Default Re: Trio 9R-59D receiver problems.

John yes so i went through fitting all 3 caps again . You might think it is a bit crude but i started on it again at 9 pm and did it all in one, rather than fitting each one in to their right places and then later have to remove them This was just to male sure that C40 41 42 was all good.

And yes you right it was no difference Still have the hum . See picture..
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Old 26th Jan 2019, 11:36 am   #147
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Default Re: Trio 9R-59D receiver problems.

Are the capacitors connected the right way round? The arrows on the casing point to the NEAGTIVE end.

EDIT. Forget that, I can see the grooves at the POSITIVE end of the caps.

Short of moving the output transformer around there's nothing more I can suggest. The leads to the output transformer look to be very close to the mains transformer which is not good.

You should not assume that the existing smoothing caps are good.

Eliminating the hum may be beyond your capabilites.
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Old 26th Jan 2019, 12:06 pm   #148
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Default Re: Trio 9R-59D receiver problems.

Ho hum ('scuse pun).….Back in my day it would be a two screw drivers job to try and narrow things down.

Post number 1 anything to do with it?

Lawrence.
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Old 26th Jan 2019, 4:24 pm   #149
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Default Re: Trio 9R-59D receiver problems.

Trevor,
I have marked a screened wire with a # symbol in the attached photo. Where is the other end connected ?

John
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Old 26th Jan 2019, 6:01 pm   #150
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Default Re: Trio 9R-59D receiver problems.

Quote:
Originally Posted by Humptydumpty View Post
John yes so i went through fitting all 3 caps again . You might think it is a bit crude but i started on it again at 9 pm and did it all in one, rather than fitting each one in to their right places and then later have to remove them This was just to male sure that C40 41 42 was all good.

And yes you right it was no difference Still have the hum . See picture..
I might be mistaken, (I hope I am), but in the picture in post 146, it looks to me that the +ve ends of the news caps are connected to the three +ve tags of the old can, in which case the new caps are in parallel with the olds ones. If so, don't expect any reduction in hum with the the old caps still in circuit.
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Old 26th Jan 2019, 6:13 pm   #151
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Default Re: Trio 9R-59D receiver problems.

It doesn't look like that to me David.

The red wires have been disconnected from the can and connected to the positive ends of the new caps.
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Old 26th Jan 2019, 6:14 pm   #152
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Default Re: Trio 9R-59D receiver problems.

David,
It does look as if one capacitor is connected to a +ve tag at the bottom of the can. I think the other two are connected only to the red wires, which have been removed from the tags.

John
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Old 26th Jan 2019, 6:19 pm   #153
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Default Re: Trio 9R-59D receiver problems.

Trevor,
Can you confirm that all three red wires were disconnected from the +ve tags ?

John
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Old 26th Jan 2019, 6:23 pm   #154
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Default Re: Trio 9R-59D receiver problems.

The earth wire of the mains flex seems to run for miles under the chassis and I can't see where it terminates. It would be better if it were connected to the chassis close to where the mains flex enters the set. I wouldn't have knotted the flex either, but this seems to be common practice with some vintage mains flexes.
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Old 26th Jan 2019, 6:33 pm   #155
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Default Re: Trio 9R-59D receiver problems.

It seems to be terminated on the left of the chassis near the dial in the photo of #146.
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Old 26th Jan 2019, 6:42 pm   #156
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Default Re: Trio 9R-59D receiver problems.

It's clearer in post #139. Still a long way to route an earth wire though.

These sets originally had a two core single insulated mains flex with the OFF/ON switch in one leg and the mains fuse in the other. I wouldn't argue against the provision of a three core mains flex, but wonder whether its provision has contributed to the mains hum problem?

I never regarded the level of mains hum from these sets as being excessive, but on the other hand I never used mine with headphones.
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Old 26th Jan 2019, 7:33 pm   #157
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Default Re: Trio 9R-59D receiver problems.

My 9R59DS still has the original two core mains lead with a separate earth. The level of mains hum was always acceptable when using an external loudspeaker but not when using headphones. I found that almost all of the hum was induced in the output transformer due to the very close location of the mains transformer. Turning the o/p transformer by 90 degrees to the right produced a remarkable reduction.

John
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Old 26th Jan 2019, 8:09 pm   #158
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Default Re: Trio 9R-59D receiver problems.

I wouldn't disagree with any of that. The mention of constant hum is first reported in post #10, but there is no mention of headphones.
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Old 26th Jan 2019, 10:01 pm   #159
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Default Re: Trio 9R-59D receiver problems.

All wires [red] are disconected from the can and wired up indvidualy to the caps .
As i was told to do it . I removed the three red wires from the can and conect to possitive on each cap. All the negative wires were put together joined up to a black wire just to save time ,then goes to the earth on the chassis.
Same hum with head phones as per the speaker .
To day i moved everything back as it was , ie caps removed and the red wires rewired to original can. I reworked the mains lead and fixed it down to stop any movement . Graham i see nothing in the picture .
Also removed the transformer to its original place back up on deck. Bit late now i will post pictures Sunday .. The receiver is still working well . After my hamfisted workmanship. lol .. Trev
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Old 27th Jan 2019, 10:54 am   #160
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Default Re: Trio 9R-59D receiver problems.

Last week i picked up another reciver just the same .And as i said to David this also has the bad hum . And in the pictures that i posted at the start you can see fallout from the inside of the C40-42 .This other receiver is also from the same stable .Only change to it was the mains lead had a twin wire . I changed that as soon as it came to see if it would cure the hum --it did not
Set 2 came in handy,just to check out where all the components connect or go to for comparison .
Anyway back to set no1 .
Its all back in the original order .
To -day i will remove the bottom cover to check out the earphone socket .It was loose when it came .And to secure it might have took a little bit of damage ,i dont know till i look at it
I will remove both wires and give it another try .May be its making contact in side . Another question the set we are sorting right now the mains lead wires were brown to the selector on and off switch ,blue nutral to the fuse , And earth goes to earth of chassis .This was how the set came to me .Would that be the right way it sould be wired . I re fitted the mains wire it had been tied in a knot to secure it .You will see in early pictures and and it looked real bad .
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