Latest find- Philips PH4212 (Cossor CR4212)

[Tractionist]

Nice find Raymo - I can see how it would 'grow' on one ..... looks very 'useable' {+ clean and intact}!

Of course ..... anything with a Philips connection is likely to be slightly quirky ... particularly in terms of dismantling. However, the FM front end looks pretty conventional - thankfully!

Let us know how you get on eh?

[Cathode Ray]

So good news to report lads!

I changed the black tar caps and measured a few other suspects but they were good.
Even the 50uf+50uf DC smoothing cap was good.

Applied power in the usual first time manner, Isolation trafo + bulb + variac and all was good so she took full the mains no bother.
The good:
Dial bulb still works.
Tunes in on all bands.
Sound on FM is very good, I just have the one speaker hooked up but it's very nice, there is a tweeter in the speaker as someone mentioned earlier. Bass is good too, made my bench vibrate!
Magic eye also works but a bit dim.

The bad:
It had a short in the tuning cap on one gang, it shorted at 50% mesh. But some close inspection led to a bent vein on the outside, easy fix.
The volume pot is in poor shape, very noisy and scratchy despite the use of contact spray. It may need to be opened and cleaned. But it's a bu**er to get at, the glass dial and tuning assembly needs to be removed!
Some FM stations close to 104 MHz sound distorted, so it may need some alignment.

But other than that, it's in good shape.
I think this will be my go-to radio, it's got great sound.

Here is a short video of the audio pot problem and a sample of the sound.

https://youtu.be/dh9w11UfQXg


Cheers and thanks for the help folks.

Ray

[Cathode Ray]

Folks ,
Having used the radio for a few evenings I can hear distortion on some FM stations. But not on the quality stations like RTE who I guess stick to the correct deviation and pre-emphesas rules.
I've read that many stations tweek their deviation well beyond approved standards
I've also read that the IF transformer bandwidth can be widened by applying a resistor, it looses some gain at the same time.

Does anyone got experience of this and could recommend a resistor value I could start with ?

Thanks

[G6Tanuki]

Re: the distortion - it would also be worth checking the electrolytic in the discriminator - if that dries out or goes leaky you can get a 'scratchy' sounding distortion on modulation peaks because the averaged DC level of the audio becomes incompatible with the audio-frequency voltage-swing.

[Cathode Ray]

Good suggestion alright , but I've already changed that cap. It was 4uf.

Thanks
Ray

[stitch1]

Do you have a decent AE? With mine I find there's distortion if I don't have the FM dipole in right position.

Just a thought

John

[Cathode Ray]

Thanks John,
That helps a bit, but I can still hear notable hiss / sibilance on speech.