Bush 82CL squealing

[AD360 Rob]

Without exception, every Hunts black (or brown) low value capacitor has been leaky to some degree even using a digital meter to check. Whilst the majority may not have an effect on the circuit with low voltages my philosophy is that they're not going to get better, only worse and like others, I'd rather not be taking a set apart again to replace what I could have done for a few pence the first time. Electrolytics I find are a mixed bag with even those horrible looking Plessey red & black still capable of being ok after all these years (although that type do fail more ofthen than others)

[Radio Scotland]

Originally Posted by AD360 Rob

Without exception, every Hunts black (or brown) low value capacitor has been leaky to some degree even using a digital meter to check. Whilst the majority may not have an effect on the circuit with low voltages my philosophy is that they're not going to get better, only worse and like others, I'd rather not be taking a set apart again to replace what I could have done for a few pence the first time. Electrolytics I find are a mixed bag with even those horrible looking Plessey red & black still capable of being ok after all these years (although that type do fail more ofthen than others)

Yeah may as well i suppose, Another few caps isn't going to add much to the work load. Although i'm not sure what type of capacitors would be a good substitute for the hunts.


Jay.

[crackle]

I have found the wax paper and mould-seal type caps hardly need replacing in these 9 volt circuits, the leakage is insignificant, due to the lower impedance circuits.
The radio looks so much more original with its old components.
Replace what is faulty. Unless you have a radio with one of those Mullard modules, you wont want to keep taking those out of circuit.
Mike

[Radio Scotland]

Originally Posted by crackle

I have found the wax paper and mould-seal type caps hardly need replacing in these 9 volt circuits, the leakage is insignificant, due to the lower impedance circuits.
The radio looks so much more original with its old components.
Replace what is faulty. Unless you have a radio with one of those Mullard modules, you wont want to keep taking those out of circuit.
Mike

Cheers for your input crackle, But theres only three of them so may as well change them while i have the radio dismantled, One has already broke so chances are the other two will follow suit soon enough.

I'm only seeing six electrolytics in this radio, Where is the seventh hiding ?

[jonnybear]

Probably hiding under the loudspeaker.
John

[Radio Scotland]

Originally Posted by jonnybear

Probably hiding under the loudspeaker.
John

I've seen that one john.


Jay

[jonnybear]

Originally Posted by Radio Scotland

I've seen that one john.


Jay

Have a look at this page may help, someone in the past may have snipped one out so you will have to double check the circuit.
http://www.richardsradios.co.uk/bushtr82c.html. no connection.
John

[Radio Scotland]

Originally Posted by jonnybear

Have a look at this page may help, someone in the past may have snipped one out so you will have to double check the circuit.
http://www.richardsradios.co.uk/bushtr82c.html. no connection.
John

Cheers john but i can't enlarge those pics. So its hard to tell, Iv'e a feeling its right under my nose



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[img]************************J4XM5fXB/IMAG0261.jpg[/img]

[ms660]

In your photo of chassis underside, the standoff pin that the 56k (R16) and the 8.2k (R13) are connected to is where the -ve end of C24 should be connected, the orange wire from that pin goes to IFT1 as expected but there's another un-insulated wire that is connected to the above mentioned standoff pin, where does that go to?

Lawrence.

[Radio Scotland]

Originally Posted by ms660

In your photo of chassis underside, the standoff pin that the 56k (R16) and the 8.2k (R13) are connected to is where the -ve end of C24 should be connected, the orange wire from that pin goes to IFT1 as expected but there's another un-insulated wire that is connected to the above mentioned standoff pin, where does that go to?

Lawrence.

Not sure which un-insulated wire your referring to lawrence, Does it look like there is a cap missing ?

[ms660]

Originally Posted by Radio Scotland

Not sure which un-insulated wire your referring to lawrence, Does it look like there is a cap missing ?

The one that's connected to the 56K (R16) and the 8.2k (R15) and the orange wire that goes to IFT1 in your 2nd photo link.

Lawrence.

[Radio Scotland]

Far as i can tell it goes to what looks like a small capacitor

[jonnybear]

Yes Laurence I was looking at that wire and wondered if it is the rivet of the a plessey capacitor?, if so where is the rest of it. there should be a 8uf to deck at that point.
John

[Radio Scotland]

[img]************************TYW8Lz8K/IMAG0267.jpg[/img]

[jonnybear]

looking at your image 0267, the white looking object with 20 in red on it looks like it could be the electrolytic you are looking for, + to chassis - to junction of 56k and 8.2k 10uf 25v would be ok. another close up picture of that device would be nice.
John

[Radio Scotland]

Originally Posted by jonnybear

looking at your image 0267, the white looking object with 20 in red on it looks like it could be the electrolytic you are looking for, + to chassis - to junction of 56k and 8.2k 10uf 25v would be ok. another close up picture of that device would be nice.
John

Didn't realise they made electrolytics as small as that back then. Take it that'll be the AGC Cap ? I'll clean up the writing on it and take another pic tomorrow,



Cheers,
Jay.

[Radio Scotland]

Originally Posted by jonnybear

another close up picture of that device would be nice.
John

Best i could do

[jonnybear]

Originally Posted by Radio Scotland

Best i could do

If the wire coming out of the other end of that device goes to chassis it must be the electrolytic in question,replace with 10uf,make sure + goes to chassis, would not worry replacing those brown square caps as they are probably good would replace the small black hunts paper capacitors though.
John

[Radio Scotland]

Originally Posted by jonnybear

If the wire coming out of the other end of that device goes to chassis it must be the electrolytic in question,replace with 10uf,make sure + goes to chassis, would not worry replacing those brown square caps as they are probably good would replace the small black hunts paper capacitors though.
John

Yeah the other end goes to the chassis, I'll be replacing the hunts anyway as they are cracked.


Cheers
Jay.

[Radio Scotland]

Could anybody tell me if it would be ok to replace the three hunts capacitors with ceramics ?



Cheers