Re: P329 WG6100 HV box difference

I think your "fine tuning" speculation is the more likely of the two.

R929 and R930 are part of a voltage divider. The other half of the
voltage divider is the resistor array that contains the focus and
brightness (G2) adjustments.

Without the 240K resistor you have an adjustment range of 47K to 147K.
With the resistor installed you have a range of 39.3K to 91.2K. 91.2K
is only 60% of the original maximum settings. It would definitely make a
big change in where R930 would have to be set.

My guess is this change corresponds with a change of the focus /
brightness assembly. It could be they spec'd more than one supplier of
focus / brightness assemblies, and there was enough of a difference
between them that they needed this resistor to compensate for those
differences.

On 5/14/2011 3:13 PM, Clay Cowgill wrote:
> Just speculation here, but looking at the pic Andy posted, I wonder if
> it's just a safety/redundant component? It would appear to simply be
> in parallel with R929 and the HV trip pot, so maybe it's there just in
> case the pot (or R929) failed or someone tried to turn the pot too far
> one way... (Or maybe they're trying to fine-tune the adjustment range
> for the HV trip a bit more.)
> -Clay
>
> ------------------------------------------------------------------------
> *From:* owner-vectorlist@vectorlist.org
> [mailto:owner-vectorlist@vectorlist.org] *On Behalf Of *Andrew Welburn
> *Sent:* Saturday, May 14, 2011 2:25 PM
> *To:* vectorlist@vectorlist.org
> *Subject:* Re: VECTOR: P329 WG6100 HV box difference
>
> I wonder why it was there too, but cleary there are two types of
> P329 pcb, the one described in the manual without, and this one,
> with... there don't appear to be any other differences that i can
> see. I have had to populate the entire pcb with components so far,
> and after powering it up this evening after a day of filling it
> has blown both fuses on the deflection. I'm done for the day, i'll
> look tomorrow, but i can;t think that even if it wasn't in-circuit
> it'd cause the fuse blow.. the hv and t901 are unknowns, and
> everything else is brand new, could be an error on my part
> however. I have 4 others to sort out too.. joy.
> Maybe someone might want to make a note of this for the FAQ? i
> havn't seen it referenced.
>

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Received on Sun May 15 02:59:17 2011