Broken ferrite rod - quiet TR82C - UK Vintage Radio Repair and Restoration Discussion Forum

Avid_Nerdlinger · 30th Apr 2019, 6:26 pm

I got a not-working Bush TR82C. Replaced a 100uF electrolytic (C22) which cured the motorboating now it works OK in terms of finding the few stations I can reach here but it is very quiet. All the voltages on the service sheet seem about right. This is the first one of these I've looked at so I didn't notice at first that the two short ferrite rod aerials are actually supposed to be one long rod and the middle bit is missing...

Any thoughts as to whether this broken rod might account for it being quiet?

Battery is a good one. There are other old caps which might need replacing but I haven't found any more faults measuring their capacitance and dc resistance, I'm waiting on an ESR meter from China before I start really ripping things up.

Simon Gittins · 30th Apr 2019, 6:45 pm

Yes, a broken rod will affect performance; they can be glued back together but this doesn't help if the middle is missing altogether.

A replacement rod is ideal but moving the coils along what is left may improve things.

Sideband · 30th Apr 2019, 9:50 pm

It's a long rod on these as well. You may have to find another scrap set to get one.

Avid_Nerdlinger · 30th Apr 2019, 10:14 pm

How about filing the broken ends and gluing in a new section of ferrite rod...?

Jolly 7 · 30th Apr 2019, 10:45 pm

Here's a scrap unbroken ferrite rod of the dimensions from a non-working Bush set. Please PM me for details if you are interested in purchasing.

Avid_Nerdlinger · 6th May 2019, 8:57 am

Thanks again Jolly, as PM'd I ordered a 100mm section (99p from Chinese ebay seller) for a repair attempt.

I connected the new long wire antenna in my loft and this radio burst into life, I was easily able to make strong channels too loud and distorted by turning the volume up. Hopefully gluing a section of ferrite in will fix it.

Sideband · 6th May 2019, 9:21 am

There are different grades of ferrite rod...some more dense than others. Gluing a random section in might not be the best solution but worth a try of course. I think I have the exact rod here somewhere from a scrapper so it's also up for grabs if your repair is unsuccessful.

Avid_Nerdlinger · 19th May 2019, 4:42 pm

Got my 99p 100mm ferrite rod. It fixes the quietness, it made a remarkable improvement just as it was offered up to the gap. I cleaned the flat ends of the broken bits with a file and super-glued them to each end of the new section, then I was able to move the coil formers into the same position as in my Dad's TR82B and poured some candle-wax on to hold it in place. The finished rod is a bit crooked but it works great, Radio 4 LW gets too loud and distorted at less than half volume.

30th Apr 2019, 6:26 pm	#1
Avid_Nerdlinger Pentode Join Date: Apr 2019 Location: Durness, Sutherland, UK. Posts: 108	Broken ferrite rod - quiet TR82C I got a not-working Bush TR82C. Replaced a 100uF electrolytic (C22) which cured the motorboating now it works OK in terms of finding the few stations I can reach here but it is very quiet. All the voltages on the service sheet seem about right. This is the first one of these I've looked at so I didn't notice at first that the two short ferrite rod aerials are actually supposed to be one long rod and the middle bit is missing... Any thoughts as to whether this broken rod might account for it being quiet? Battery is a good one. There are other old caps which might need replacing but I haven't found any more faults measuring their capacitance and dc resistance, I'm waiting on an ESR meter from China before I start really ripping things up.

30th Apr 2019, 6:45 pm	#2
Simon Gittins Heptode Join Date: Jan 2006 Location: Cornwall, UK. Posts: 506	Re: Broken ferrite rod - quiet TR82C Yes, a broken rod will affect performance; they can be glued back together but this doesn't help if the middle is missing altogether. A replacement rod is ideal but moving the coils along what is left may improve things.

30th Apr 2019, 9:50 pm	#3
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,572	Re: Broken ferrite rod - quiet TR82C It's a long rod on these as well. You may have to find another scrap set to get one. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

30th Apr 2019, 10:14 pm	#4
Avid_Nerdlinger Pentode Join Date: Apr 2019 Location: Durness, Sutherland, UK. Posts: 108	Re: Broken ferrite rod - quiet TR82C How about filing the broken ends and gluing in a new section of ferrite rod...?

30th Apr 2019, 10:45 pm	#5
Jolly 7 Octode Join Date: Feb 2018 Location: Southampton, Hampshire, UK. Posts: 1,061	Re: Broken ferrite rod - quiet TR82C Here's a scrap unbroken ferrite rod of the dimensions from a non-working Bush set. Please PM me for details if you are interested in purchasing. Attached Thumbnails

6th May 2019, 8:57 am	#6
Avid_Nerdlinger Pentode Join Date: Apr 2019 Location: Durness, Sutherland, UK. Posts: 108	Re: Broken ferrite rod - quiet TR82C Thanks again Jolly, as PM'd I ordered a 100mm section (99p from Chinese ebay seller) for a repair attempt. I connected the new long wire antenna in my loft and this radio burst into life, I was easily able to make strong channels too loud and distorted by turning the volume up. Hopefully gluing a section of ferrite in will fix it.

6th May 2019, 9:21 am	#7
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,572	Re: Broken ferrite rod - quiet TR82C There are different grades of ferrite rod...some more dense than others. Gluing a random section in might not be the best solution but worth a try of course. I think I have the exact rod here somewhere from a scrapper so it's also up for grabs if your repair is unsuccessful. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

19th May 2019, 4:42 pm	#8
Avid_Nerdlinger Pentode Join Date: Apr 2019 Location: Durness, Sutherland, UK. Posts: 108	Re: Broken ferrite rod - quiet TR82C Got my 99p 100mm ferrite rod. It fixes the quietness, it made a remarkable improvement just as it was offered up to the gap. I cleaned the flat ends of the broken bits with a file and super-glued them to each end of the new section, then I was able to move the coil formers into the same position as in my Dad's TR82B and poured some candle-wax on to hold it in place. The finished rod is a bit crooked but it works great, Radio 4 LW gets too loud and distorted at less than half volume.