Philco bt1840 width coil. - UK Vintage Radio Repair and Restoration Discussion Forum

radiograham · 7th Oct 2021, 1:05 am

Hi,i dug this tv out recently this is the one i have been rebuilding the rf chassis on.I have found that the width coil on the lopt has been twisted at some time breaking the connections,i am going to try rewinding it,the original wires that go from the coil to the lopt are buried in the black pitch that is round the lopt i think i have id these so will be able to run these on the surface as originals are brittle.The one i intend to rewind was two coils of 450 turns wound in same direction with the two outer conn's earthed and the inners going to the other conns,doe's this sound right? if i try the set without the coil i think i should still get something but no control of width? also what was the core material used?. Graham.

radiograham · 10th Oct 2021, 10:26 pm

Rewound the width coil on slightly bigger dia former and using a core from a Murphy V202 as the original was missing,works well and am pleased with the results,still wondering what the original core material was,any ideas? Graham.

7th Oct 2021, 1:05 am	#1
radiograham Hexode Join Date: Oct 2017 Location: Manchester, UK. Posts: 363	Philco bt1840 width coil. Hi,i dug this tv out recently this is the one i have been rebuilding the rf chassis on.I have found that the width coil on the lopt has been twisted at some time breaking the connections,i am going to try rewinding it,the original wires that go from the coil to the lopt are buried in the black pitch that is round the lopt i think i have id these so will be able to run these on the surface as originals are brittle.The one i intend to rewind was two coils of 450 turns wound in same direction with the two outer conn's earthed and the inners going to the other conns,doe's this sound right? if i try the set without the coil i think i should still get something but no control of width? also what was the core material used?. Graham.

10th Oct 2021, 10:26 pm	#2
radiograham Hexode Join Date: Oct 2017 Location: Manchester, UK. Posts: 363	Re: Philco bt1840 width coil. Rewound the width coil on slightly bigger dia former and using a core from a Murphy V202 as the original was missing,works well and am pleased with the results,still wondering what the original core material was,any ideas? Graham.