The Ultra V17-53. 1958/9. - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

Heatercathodeshort · 2nd Jan 2022, 6:36 pm

No Bob. It's the very bright raster showing through the very thin aluminising on the inside of the tube. The Aluminium coating is micro thin. John.

bobhowe · 2nd Jan 2022, 7:01 pm

Quote:

Originally Posted by Heatercathodeshort

No Bob. It's the very bright raster showing through the very thin aluminising on the inside of the tube. The Aluminium coating is micro thin. John.

Hi John you are right you can see it in a darkened room never seen that before you learn something every time hears a picture of the CRT gun you can see the signature of who assembled it in the factory or what type of gun it is ?

Graham G3ZVT · 2nd Jan 2022, 9:05 pm

This was before the Modern Slavery laws, it says "I am being held captive in a tube factory, send help".

FERNSEH · 2nd Jan 2022, 10:23 pm

First attachment shows the straight gun assembly in the Mazda CME1702.
No ion trap is employed with this tube. Same for the CME1402.
The second attachment shows the bent gun gun assembly fitted in the Mullard AW43-80. This tube uses an ion trap magnet.
Third attachment shows the figures on the gun in Bob's CRT.

DFWB.

bobhowe · 3rd Jan 2022, 2:46 pm

Quote:

Originally Posted by FERNSEH

First attachment shows the straight gun assembly in the Mazda CME1702.
No ion trap is employed with this tube. Same for the CME1402.
The second attachment shows the bent gun gun assembly fitted in the Mullard AW43-80. This tube uses an ion trap magnet.
Third attachment shows the figures on the gun in Bob's CRT.

DFWB.

Hi David the gun on the Mullard AW43-80 why was it made like that

Cobaltblue · 3rd Jan 2022, 2:56 pm

Its an Ion trap gun.

First used on the Cossor 902 in 1947, Tube type 75K.

The electrons and Ions are shot toward the side of the tube instead of the screen.

The ION trap magnet corrects the beam of electrons back towards the screen.

It then gets deflected by the scan coils in the normal way.

The much heavier IONs continue on their journey to hit the side of the tube or the rest of the electron gun assembly.

It prevents the ION burns in the centre of the tube.

Cheers

Mike T

bobhowe · 3rd Jan 2022, 4:06 pm

Hi Mike thanks for the explanation

FERNSEH · 3rd Jan 2022, 11:02 pm

The 10BP4 and 12LP4 CRTs employed a dual magnet ion trap.
The electrodes of the tetrode gun are in-line but note the angle of the gap between the first and second anodes.

DFWB.

bobhowe · 4th Jan 2022, 4:40 pm

Hi David interesting findings

2nd Jan 2022, 6:36 pm	#21
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,169	Re: The Ultra V17-53. 1958/9. No Bob. It's the very bright raster showing through the very thin aluminising on the inside of the tube. The Aluminium coating is micro thin. John.

2nd Jan 2022, 9:05 pm	#23
Graham G3ZVT Dekatron Join Date: May 2010 Location: Greater Manchester, UK. Posts: 19,438	Re: The Ultra V17-53. 1958/9. This was before the Modern Slavery laws, it says "I am being held captive in a tube factory, send help". __________________ -- Graham. G3ZVT

2nd Jan 2022, 10:23 pm	#24
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,459	Re: The Ultra V17-53. 1958/9. First attachment shows the straight gun assembly in the Mazda CME1702. No ion trap is employed with this tube. Same for the CME1402. The second attachment shows the bent gun gun assembly fitted in the Mullard AW43-80. This tube uses an ion trap magnet. Third attachment shows the figures on the gun in Bob's CRT. DFWB. Attached Thumbnails

3rd Jan 2022, 2:56 pm	#26
Cobaltblue Moderator Join Date: Dec 2010 Location: Exeter, Devon and Poole, Dorset UK. Posts: 7,780	Re: The Ultra V17-53. 1958/9. Its an Ion trap gun. First used on the Cossor 902 in 1947, Tube type 75K. The electrons and Ions are shot toward the side of the tube instead of the screen. The ION trap magnet corrects the beam of electrons back towards the screen. It then gets deflected by the scan coils in the normal way. The much heavier IONs continue on their journey to hit the side of the tube or the rest of the electron gun assembly. It prevents the ION burns in the centre of the tube. Cheers Mike T __________________ Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk

3rd Jan 2022, 4:06 pm	#27
bobhowe Heptode Join Date: Jun 2005 Location: Sunderland, Tyne and Wear, UK. Posts: 802	Re: The Ultra V17-53. 1958/9. Hi Mike thanks for the explanation __________________ BVWS . RSGB Member

3rd Jan 2022, 11:02 pm	#28
FERNSEH Dekatron Join Date: Mar 2005 Location: Gateshead, Tyne and Wear, UK. Posts: 7,459	Re: The Ultra V17-53. 1958/9. The 10BP4 and 12LP4 CRTs employed a dual magnet ion trap. The electrodes of the tetrode gun are in-line but note the angle of the gap between the first and second anodes. DFWB. Attached Thumbnails

4th Jan 2022, 4:40 pm	#29
bobhowe Heptode Join Date: Jun 2005 Location: Sunderland, Tyne and Wear, UK. Posts: 802	Re: The Ultra V17-53. 1958/9. Hi David interesting findings __________________ BVWS . RSGB Member