Thorn TX9 CRT Swap - UK Vintage Radio Repair and Restoration Discussion Forum

MrSilenVid · 11th May 2025, 1:42 pm

Hello.

I have two TX9s, both with a 20" CRT. I was wondering if it's possible to simply swap the tubes. One of the tubes has bad screen burn.

One of the sets is a stereo model with a MK III/1044 chassis and the tube is a Mullard A51-580X.

The other is a MK1 1001 chassis with a AXT51-001 tube.

Can I do a straight swap? Would it be possible to do it without removing the yokes? Since it will be a lot easier.

Thanks.

jayceebee · 11th May 2025, 3:36 pm

Not a problem, it’s probably the same CRT. The AXT label was factory production rationalisation affixed by Thorn where CRTs were procured from different manufacturers, they could have different type numbers but were equivalent.

John.

1955APREN · 11th May 2025, 5:00 pm

DO NOT REMOVE THE YOKES shape as complete uint . I think that the plugs to
scan coils are the same type/
Derrick

Welsh Anorak · 13th May 2025, 8:15 am

The only distant bell ringing is that for some reason the locating pin of the line scan coil plug was the opposite orientation on early models. Not a problem - snip the locating pin off and reverse it if necessary.

A colleague of mine sent back a set with it fitted backwards (he'd tested the set on the bench with a mirror as you do and hadn't noticed). The customer had it for months before complaining....

11th May 2025, 1:42 pm	#1
MrSilenVid Tetrode Join Date: Dec 2024 Location: Manchester, North West, UK. Posts: 65	Thorn TX9 CRT Swap Hello. I have two TX9s, both with a 20" CRT. I was wondering if it's possible to simply swap the tubes. One of the tubes has bad screen burn. One of the sets is a stereo model with a MK III/1044 chassis and the tube is a Mullard A51-580X. The other is a MK1 1001 chassis with a AXT51-001 tube. Can I do a straight swap? Would it be possible to do it without removing the yokes? Since it will be a lot easier. Thanks.

11th May 2025, 3:36 pm	#2
jayceebee Heptode Join Date: Jun 2007 Location: Durham, County Durham, UK. Posts: 667	Re: Thorn TX9 CRT Swap Not a problem, it’s probably the same CRT. The AXT label was factory production rationalisation affixed by Thorn where CRTs were procured from different manufacturers, they could have different type numbers but were equivalent. John.

11th May 2025, 5:00 pm	#3
1955APREN Heptode Join Date: Nov 2010 Location: Market Drayton, Shropshire, UK. Posts: 532	Re: Thorn TX9 CRT Swap DO NOT REMOVE THE YOKES shape as complete uint . I think that the plugs to scan coils are the same type/ Derrick

13th May 2025, 8:15 am	#4
Welsh Anorak Dekatron Join Date: Apr 2005 Location: North Wales, UK. Posts: 7,670	Re: Thorn TX9 CRT Swap The only distant bell ringing is that for some reason the locating pin of the line scan coil plug was the opposite orientation on early models. Not a problem - snip the locating pin off and reverse it if necessary. A colleague of mine sent back a set with it fitted backwards (he'd tested the set on the bench with a mirror as you do and hadn't noticed). The customer had it for months before complaining.... __________________ Glyn