It was all going so well...

[SKEXIS1]

.....until I got to the stage of aligning the current project; a Masteradio D111.

Feeling good having got some annoying hum sorted and having done lots of other work, I started to go through the alignment process. Have a look at the attached photos.

Yes, one tuning coil core does look shorter than the other and yes, the adjuster end does look like it's sheared

No wonder LW was all over the place - couldn't even find radio 4

I can't bring myself to describe the chain of events that got me to this point, suffice to say that a certain amount of my own ham-fistedness was to blame

Would anyone have any good suggestions on how I can get back on track?

As you can see from the second photo the core itself can be separated from the adjusting thread, but I don't know whether it's possible to get hold of a replacement. I don't suppose anyone has any of these kicking around the workshop? If so, it would be great to hear from you!

It measures approx 5mm in diameter and is 12mm long.

I guess the ideal would be to get the full core / adjuster assembly, specially as the end has sheared off. The next task is to remove the old adjuster from the brass block - it's seized solid in there at the moment....

Any advice would be most welcome!

Thanks

Andy

[Steve_P]

A little bit of glue works wonders.

Is the IF okay and do MW and SW work OK?

Cheers,

Steve P.

[AlanBeckett]

Andy,
Is the 'short' core actually broken?
Is it just a matter of a new adjuuster so that the core can be screwed further into the coil?
If the thread is anything sensible it wouldn't be much of a job to fabricate a new screw, and as Steve says, a bit of glue works wonders.
Alan

[SKEXIS1]

Unfortunately the rest of the core got crushed.....

To be honest, I've not checked how it's working at the mo, I had to come out of the workshop for a while to calm down!

When I go back in there I'll go through the alignment again and see how it sounds with it in there as it is.

The IF is OK, thankfully those cores were all easy to turn and I was very gentle! These two are the cores for the oscillator coils on MW and LW respectively.

I think I've just clocked why my LW alignment was so far out; the trader sheet for this model (829) states in the LW oscillator alignment section: "tune to 2,000m on scale, feed in a 2000m (1,500 kc/s) signal". I don't think it means 1,500 kc/s does it? Shouldn't it be 150 kc/s? Typo-tastic

[Boom]

It looks a very similar problem to the DAC90 IF slugs which fall to bits. In fact you might even find that they fit if you can find any. I've glued several of these slugs back together but it is a very fiddly job.

[AlanBeckett]

1.5Mc/s would seem to be a bit ambitious
The whole thing looks backwards. Why 2000m?
Why not 1500m (200kc/s)? I know it would have clashed with the 'Light Programme' of old, but that would be the one you wanted to get right.
Alan

[Station X]

I had a similar problem with a wartime civvy set and successfully glued everything back together, including the fragments of the core, using Araldite Precsion two part epoxy which has a long setting time. The core was glued together first, the bits being held in place with masking tape whilst the glue set. I then carefully drilled out the hole for the brass adjuster screw. I used a lathe for that. but you should get away with holding a twist drill in your hand. It's just a matter of removing excess and old glue. When gluing the slug to the brass it's important to keep everything concentric so that the slug can move freely in the former.

[Herald1360]

For long wave I should think just about any ferrite slug with the right diameter, glued to a cheese head brass screw with the right thread, would sort it. Even a threaded one, ex IFT maybe?

Chris