Bush TR82-CL Preset Modification - UK Vintage Radio Repair and Restoration Discussion Forum

Radio Scotland · 21st Nov 2020, 1:01 pm

The above radio has a ''208'' preset button for radio luxembourg But thats long since gone, I Was thinking of modding this button for my favourite station which transmits on 1152-khz, I presume this button works by bypassing the main tuning capacitor and switches in a fixed capacitance,

So in theory all i need to do is add capacitance to pull it down from 1.441khz to 1,152khz,

Am i right in this assumption ?

Problem is i only have a schematic for a mark 1- 82c I don't know if theres a revised schematic which shows the 208 button ?

AC/HL · 21st Nov 2020, 2:26 pm

The service data for the TR82CL is here: https://www.service-data.com/section.php/1068/1/tr82cl

Radio Scotland · 21st Nov 2020, 2:28 pm

Quote:

Originally Posted by AC/HL

The service data for the TR82CL is here: https://www.service-data.com/section.php/1068/1/tr82cl

Much Appreciated

Cheers

Jay

Sideband · 21st Nov 2020, 4:58 pm

I'm sure this pre-set is tunable over a limited frequency. I restored a 'CL' version for a friend some years ago and he asked about retuning the button to his local station. I can't remember if it was a pre-set capacitor or a coil.....I think it was a coil that tuned quite easily to his local station. I know I didn't need to change anything.

Radio Scotland · 21st Nov 2020, 5:08 pm

Quote:

Originally Posted by Sideband

I'm sure this pre-set is tunable over a limited frequency. I restored a 'CL' version for a friend some years ago and he asked about retuning the button to his local station. I can't remember if it was a pre-set capacitor or a coil.....I think it was a coil that tuned quite easily to his local station. I know I didn't need to change anything.

Thank for the info, Sounds like it might be an easier modification than i first thought, I'll take a look at the circuit diagram and figure out how it works,

Cheers

Radio Scotland · 21st Nov 2020, 10:33 pm

Looks like this might be the inductor that needs adjusted

Radio Scotland · 22nd Nov 2020, 1:36 pm

The inductor is L6, Problem is it's full of wax so i paralleled it with a variable capacitor and i can tune the top portion of the band,

The station i want is weak using the above method, Weird thing is theres two stations either side of it and they're coming in at normal strength,

Weird

21st Nov 2020, 1:01 pm	#1
Radio Scotland Heptode Join Date: Jul 2020 Location: Larkhall, South Lanarkshire, Scotland. Posts: 671	Bush TR82-CL Preset Modification The above radio has a ''208'' preset button for radio luxembourg But thats long since gone, I Was thinking of modding this button for my favourite station which transmits on 1152-khz, I presume this button works by bypassing the main tuning capacitor and switches in a fixed capacitance, So in theory all i need to do is add capacitance to pull it down from 1.441khz to 1,152khz, Am i right in this assumption ? Problem is i only have a schematic for a mark 1- 82c I don't know if theres a revised schematic which shows the 208 button ? __________________ Help!! I've been electrocuted by a glass thing that glows

21st Nov 2020, 2:26 pm	#2
AC/HL Dekatron Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 9,643	Re: Bush TR82-CL Preset Modification The service data for the TR82CL is here: https://www.service-data.com/section.php/1068/1/tr82cl

21st Nov 2020, 4:58 pm	#4
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,580	Re: Bush TR82-CL Preset Modification I'm sure this pre-set is tunable over a limited frequency. I restored a 'CL' version for a friend some years ago and he asked about retuning the button to his local station. I can't remember if it was a pre-set capacitor or a coil.....I think it was a coil that tuned quite easily to his local station. I know I didn't need to change anything. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

21st Nov 2020, 10:33 pm	#6
Radio Scotland Heptode Join Date: Jul 2020 Location: Larkhall, South Lanarkshire, Scotland. Posts: 671	Re: Bush TR82-CL Preset Modification Looks like this might be the inductor that needs adjusted Attached Thumbnails __________________ Help!! I've been electrocuted by a glass thing that glows

22nd Nov 2020, 1:36 pm	#7
Radio Scotland Heptode Join Date: Jul 2020 Location: Larkhall, South Lanarkshire, Scotland. Posts: 671	Re: Bush TR82-CL Preset Modification The inductor is L6, Problem is it's full of wax so i paralleled it with a variable capacitor and i can tune the top portion of the band, The station i want is weak using the above method, Weird thing is theres two stations either side of it and they're coming in at normal strength, Weird __________________ Help!! I've been electrocuted by a glass thing that glows