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Heatercathodeshort · 21st Sep 2018, 7:51 pm

It certainly is an odd one. Mazda traps are usually about a half inch from the base.
Have you adjusted the whole focus assembly? It can be moved closer or further away from the screen. It should focus with the dome [fine focus] mid way.

It is possible that you have low EHT. It does look a bit dull. A low emission CRM172 should focus with correct EHT voltage. It really needs to be measured to get a definite answer.

Just a thought, is the tube the original Mazda? It may be fitted with a poor grade regun and this might explain the odd ion trap position. J

21st Sep 2018, 7:51 pm	#57
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Help needed restoring a Murphy V310 It certainly is an odd one. Mazda traps are usually about a half inch from the base. Have you adjusted the whole focus assembly? It can be moved closer or further away from the screen. It should focus with the dome [fine focus] mid way. It is possible that you have low EHT. It does look a bit dull. A low emission CRM172 should focus with correct EHT voltage. It really needs to be measured to get a definite answer. Just a thought, is the tube the original Mazda? It may be fitted with a poor grade regun and this might explain the odd ion trap position. J