Transistor radio repair. Advice please.

[Philh4955]

Forgive me if some of my questions are a little naive but I am a beginner and new to this forum!
Just retired so looking for a new hobby and have been given free two radios ( Roberts R404 and Hacker RP70 Ranger) as spares or repair. I have basic DIY skills so hope to restore both but need some guidance as what is best to do
On powering up with new pp9 s both work to a fashion but have issues
Roberts: some cosmetic issues but seems ok otherwise apart from crackle every time volume knob is changed

Hacker: both band switches seem intermittent. One big problem is that the bar (graphite?) with aerial windings is snapped – can it be glued together?

Are there other general servicing things I should do?

Is there a basic guide to restoration/repair?

Thanks in advance for any help

[paulsherwin]

The first thing to do is to obtain some contact cleaner such as Servisol 10 and give all the switches and pots a squirt. You will need to get the cleaner inside the pots through a hole or aperture. Don't use WD40 for this.

The broken ferrite rod can be glued back together with Superglue, assuming the break is clean.

Both these models do have some known issues but it doesn't sound as if yours are affected. The R404 uses the AF11x series of RF transistors which are prone to failure, and the RP70 uses the Lockfit series which can also fail but for different reasons. There are lots of threads about these issues if you search the forum.

[Philh4955]

OK thanks for the rapid response. I will get some contact cleaner and report back soon!

[Wellington]

Originally Posted by Philh4955

Is there a basic guide to restoration/repair?

Some info here (towards the bottom of the page) on transistor radio restoration and repair.

Originally Posted by Philh4955

One big problem is that the bar (graphite?) with aerial windings is snapped – can it be glued together?

The bar is made from a material called ferrite. As Paul says, broken ferrite rods can be glued back together - see this thread or you can use the forum search function

[nebogipfel]

Graham (Radiocruncher) has published a large number of excellent restoration videos on Youtube ....

https://www.youtube.com/channel/UCDj...t108Cjw/videos

He is particularly interested in Hacker and Roberts sets but will tackle all sorts of things.

[GRID LEAK]

Hi there and welcome to the forum.
Regarding the broken ferrite aerial rod, if the break isn't covered by one of the coils, my usual way is to superglue it back together and cover the join with suitably sized adhesive lined heatshrink tubing. Not always possible if the break is in an awkward place. Good luck with your new hobby.
Regards.
John

[Mike. Watterson]

Originally Posted by paulsherwin

The broken ferrite rod can be glued back together with Superglue, assuming the break is clean.

Works best if thinnest amount and damp but not wet. Liquid not gel is thinner but trickier. Hold till set. Then maybe epoxy sleeve on outside if it doesn't interfere with coils or the rod seems fragile (clean off superglue if it comes apart).
The inductance is slightly reduced (more the wider the gap) which can be compensated for by moving coils away from the rod ends slightly.

[Philh4955]

Thanks for all of the advice.

A few hours in the shed this afternoon ferrite core repaired and contacts cleaned. A few cosmetic repairs and cleaning and Hacker now working perfectly and looking not too bad for a first project

[Radio Wrangler]

So there you go. A success story! You've learned a bit and built up the confidence to try something a little bit more next time if you want to.

David

[turretslug]

Beware though that the satisfaction of revitalising other folk's forlorn cast-offs can become worryingly addictive- the excuses for acquiring ever more "old junk" become less and less tenable....