Adjusting focus on Mc Michael MP17? - UK Vintage Radio Repair and Restoration Discussion Forum

Sean Williams · 23rd Apr 2007, 5:35 pm

Ok, Ive looked, and fiddled, but I want to set the focus on this set - any ideas?

Cant see anything that helps.

I want to get it as close to right as I can before Josh gets saddled with it......

Picture below.......

Heatercathodeshort · 23rd Apr 2007, 7:02 pm

Hello Sean,
The MP17 uses the Mullard AW43-80 electrostatically focused tube. The focus is usually preset by the set makers who connecting the focus electrode flylead to either boost HT, normal HT, or earth. These tubes use a pre focus gun and will retain good focus at virtually any position. Not at all critical in this respect. If its out of focus [a bit] connecting the focus lead to the boost setting will improve it slightly, very slightly but alas a replacement tube may well be required. The picture should be very high contrast with loads of reserve brilliance. Regards John.

Sean Williams · 23rd Apr 2007, 7:50 pm

hi John,

I am being hyper critical really - the picture is watchable, just ever so slightly fuzzy - I can see the line structure, and there is loads of brilliamce in reserve....

I think it is time to call it a day on this set

23rd Apr 2007, 5:35 pm	#1
Sean Williams Dekatron Join Date: Feb 2005 Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW Posts: 3,517	Adjusting focus on Mc Michael MP17? Ok, Ive looked, and fiddled, but I want to set the focus on this set - any ideas? Cant see anything that helps. I want to get it as close to right as I can before Josh gets saddled with it...... Picture below....... Attached Thumbnails __________________ Engineers make things work and have spare bits when finished

23rd Apr 2007, 7:02 pm	#2
Heatercathodeshort Dekatron Join Date: Jun 2005 Location: Warnham, West Sussex. 10 miles south of DORKING. Posts: 9,147	Re: Adjusting focus on Mc Michael MP17? Hello Sean, The MP17 uses the Mullard AW43-80 electrostatically focused tube. The focus is usually preset by the set makers who connecting the focus electrode flylead to either boost HT, normal HT, or earth. These tubes use a pre focus gun and will retain good focus at virtually any position. Not at all critical in this respect. If its out of focus [a bit] connecting the focus lead to the boost setting will improve it slightly, very slightly but alas a replacement tube may well be required. The picture should be very high contrast with loads of reserve brilliance. Regards John.

23rd Apr 2007, 7:50 pm	#3
Sean Williams Dekatron Join Date: Feb 2005 Location: St.Ippolyts, Hitchin, Hertfordshire QRA IO91UW Posts: 3,517	Re: Adjusting focus on Mc Michael MP17? hi John, I am being hyper critical really - the picture is watchable, just ever so slightly fuzzy - I can see the line structure, and there is loads of brilliamce in reserve.... I think it is time to call it a day on this set __________________ Engineers make things work and have spare bits when finished