Date   : Mon, 14 Nov 2005 21:54:29 +0000
From   : Paul J <peterbilt@...>
Subject: Re: RF Modulator Interference

Thanks for the replies,
 >Did anyone fiddle with the adjustment cores for coils in the modulator?
I opened the top of the modulator, and the ferrite slug looks intact. What
kind of screwdriver is needed to adjust, the slot in the top is just over
2mm long, by 1mm wide?
 This ferrite slug does seem to have an effect on the inrerference, If I
hold something against it, it does seem to stabilise the drift.
 The interference from the sound and disk drive, seems to be different type
of interference, possibly power related.
 Regards,
Paul.


 >>>>(I think one's accessible through the shielding, the others need the
> >>lid
> >>popping). Just wondered if someone tried that to see if it would cure
> >>
> >>the fault and then adjusted things to far and broke the core.
> >
> >
> > Seconded. Don't force the ferrite slug, it won't give much resistance
> > before it cracks. Be sure to use a plastic screwdriver.
> >
> > If that's happened with yours then the tuning will wander as the
> > ferrite pieces shift around. They'll also shake with vibrations from
> > the speaker or a disc drive on the same desk.
>
> Good point - I hadn't thought that a broken core could also be the root
> cause of the problem, but I suppose you're right. So swapping the
> modulator out could well be a complete fix....
>
> I think I might have a spare one on a parts machine if needed - just not
> sure if I still have the parts machine itself as I recall using most of
> the bits from it :)
>
> cheers
>
> Jules
>
>

<div>Thanks for the replies,</div>
<div>&nbsp;</div>
<div>&gt;Did anyone fiddle with the adjustment cores for coils in the modul
ator?</div>
<div>I opened the top of the modulator, and the ferrite slug looks intact.
What kind of screwdriver is needed to adjust, the slot in the top is just o
ver 2mm long, by 1mm wide?</div>
<div>&nbsp;</div>
<div>This ferrite slug does seem to have an effect on the inrerference, If
I hold something against it, it does seem to stabilise the drift.</div>
<div>&nbsp;</div>
<div>The interference from the sound and disk drive, seems to be different
type of interference, possibly power related.</div>
<div>&nbsp;</div>
<div>Regards,</div>
<div>Paul.</div>
<div><br>&nbsp;</div>
<div>&nbsp;</div>
<div><br>&nbsp;</div>
<div>
<blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0
px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">&gt;&gt;&gt;&gt;(I think one's a
ccessible through the shielding, the others need the<br>&gt;&gt;lid<br>&gt;
&gt;popping). Just wondered if someone tried that to see if it would cure
<br>&gt;&gt;<br>&gt;&gt;the fault and then adjusted things to far and broke
 the core.<br>&gt;<br>&gt;<br>&gt; Seconded.&nbsp;&nbsp;Don't force the fer
rite slug, it won't give much resistance<br>&gt; before it cracks.&nbsp;&nb
sp;Be sure to use a plastic screwdriver.
<br>&gt;<br>&gt; If that's happened with yours then the tuning will wander
as the<br>&gt; ferrite pieces shift around.&nbsp;&nbsp;They'll also shake w
ith vibrations from<br>&gt; the speaker or a disc drive on the same desk.<b
r><br>
Good point - I hadn't thought that a broken core could also be the root<br>
cause of the problem, but I suppose you're right. So swapping the<br>modula
tor out could well be a complete fix....<br><br>I think I might have a spar
e one on a parts machine if needed - just not
<br>sure if I still have the parts machine itself as I recall using most of
<br>the bits from it :)<br><br>cheers<br><br>Jules<br><br></blockquote></di
v><br>