Hi Dillen,

That 'little fellow' is renowned for frying transformers leaving the primary open circuit and destroying output valves for the reason you mention. I always replace it with at least 2x max voltage working of the previous valve's HT voltage to protect it, what voltage rating is the 'little fellow'?

I believe its a 400V capacitor so should be fine.

Did you experience problems with these mustard colored caps ? 

Martin

I have never had a problem with these yet provided they are the correct rating for the job.

They are available in various voltage ratings notably 160V & 400V they are all marked  -160 is too low!

Measure the DC voltage between chassis & the grid of the Output valve- should be negative. I expect the value is on the schematic

Regards

Yep, it's a 4700pF 400V component.
I double-checked it and it is absolutely fine.

I also checked the output transformer and here the result was
somewhat different to say the least;
The service sheet gives the DC ohmic values as 380 / 0.8 ohms.
The actual transformer measures 11K / 0.8 ohms - the 11 Kohms
is far too high so this transformers primary has had it. No doubt this
is the cause for the fairly low volume output.

So now I am on the lookout for an output transformer.
The service sheet gives the anode current as 33mA.
The original transformer is a Peerless CL4 and would probably
prove hard to find but a good replacement with apprx the same
values will be just as fine.

Martin

Off to the car boot sales then (if you have them in Denmark😁)

Philips Radios used CBL1's a lot so they will have a matching transformer provided it is the right physical size. If you have no luck let me know and i'll see what I have here.

Have you tried re soldering the tags? sometimes they get 'green spot' and the flux eats the copper wire 

Failing that I have some contacts who can rewind transformers -at a price. 

This thread is superb!

wow

incerdible, I'm out of words...

this is a wonderfull topic, and a wonderfull job. by the way, the beolit 39 radio is priceless...

I can't wait to see it done.

Thanks to Chris (Medogsfat) who very kindly helped me to a new output transformer.
Your help is greatly appreciated !  🤒

With this part, I will hopefully be able to get the output stage working as
it should.
The original transformer was scrutinized but no obvious faults could be seen,
the way too high primary DC resistance however, proved that it was indeed defective.

The new transformer is a brand new general purpose component. It has several
tappings on both primary and secondary and will be easy to fit inside the
speaker cloth bag.

The best suitable tappings were selected and the speaker wires attached accordingly.
The transformer was then fitted using the original mounting holes in the
speaker metal basket.

Power up.
Hmmm... the new transformer didn't provide the significant change in output volume
that I was hoping for.
It did, however, set the voltages around the output valve, particularly the anode
voltage, correct.

Martin