Re: DIY Amplifone Yoke


James, thank you very much for posting those photos... nice ones, at
that.

The yoke certainly does look very regular, identical in shape to a G07
yoke I have here, although despite the vertical winding differences, I
can also see that there's slightly fewer horizontal windings as
well.

Measuring it as-is, I find:

Electrohome red 1.59mh 2.1ohms X
G07 white
brown 102.7mh 56ohms Y
gray

And borrowing Kossow's G08-003 measurements:
Electrohome blue .41mH .43 ohms X
G08 red
green .52mH 1.0 ohms Y
yellow

I don't have Amplifone inductances, but a fellow named "Amplifone" on
ebay was nice enough to provide me with DC readings:

Amplifone ?mh 0.9 ohms X
?mh 1.3 ohms Y

So the measurements reflect what can be seen visually -- a bit fewer
windings on X, and far fewer on Y.

I'm assuming the Y numbers are larger in general just because vertical
doesn't have to work as hard (in a raster) and travel as far in a
vector.

Since the G08 uses a 100 degree tube, the deflection board has to work
harder with higher currents for that angle than for 90... also borne
out in the numbers above ... so one would not need to rewind a G07
yoke for numbers quite as radical as those of the G08.

I'm also guessed one only needs to end up in the ballpark, not nail
some certain impedances spot on. So I think my first experiment will
be in leaving X as it is at 1.59mh, and aiming for 1.25x that for Y,
or 2.0mh.

Another, perhaps easier, option would be to peel off a few X windings
to get it down to about 1mh, and shoot for 1.25mh for Y. The G08
clearly has the current to handle those low impedances, and I suspect
this will help keep the vector speeds up.

JS



.

Relevant Pages

  • Re: DIY Amplifone Yoke
    ... yoke, say off a G07? ... Superficially, it just looks like a standard yoke, but the vertical windings are ... Much thicker gauge wire and significantly fewer windings. ...
    (rec.games.video.arcade.collecting)
  • Re: Yoke Replacement
    ... > 9" color TV/radio combo I picked up in the trash, had a badly burned yoke. ... > was able to isolate and insulate the shorted windings, ... > magnet wire that I could do this with. ... More the the impedance is the inductance. ...
    (sci.electronics.repair)
  • bush ws6674 widescreen tv
    ... the pins on the horizontal output to the yoke connecter were burned with ... bit low resistance but could this be because its a widescreen tv and needs ... assumption that the poor solder on the horizontal connector caused arcing ...
    (sci.electronics.repair)
  • FIXED! Samsung projector tv, how I locate a bad yoke?
    ... That was lucky one, the green yoke horizontal (pair of windings, the ... one halve of horizontal windings went partially toast-burned style ... that is very lucky that owner didn't have to pay for a CRT! ...
    (sci.electronics.repair)
  • Re: Is there any reason no one can reproduce Ampliphone Vector Monitor Boards
    ... the impeadence differences are very small when comparing horozontal ... yoke here measuring 80 ohms, in comparison to the g08 yoke measuring ... about 1 ohm. ... windings were around 1ohm and 1.5mH. ...
    (rec.games.video.arcade.collecting)