Re: P329 WG6100 HV box difference

So i'm wondering if its worth even loading this resistor in, i'm thinking not. This morning I did a few checks and noticed the BU207 (which i havn't replaced) was bolted to the box without a heatsink.. (wasn't me guvnor!) so i put in an insulator...

Bingo, it works. It cranks to 24kv.. i set the trip at about 22.5kv and adjusted it down to 19.5kv, all seems fine, i don't think i'll put that resistor in, I can't see any advantage, but its good to know about. The HV trip pot is adjusted to about the middle of its turn anyway so there is no real problem with its range.

Now onto the next 4.

--
Andrew Welburn
http://www.andys-arcade.com
  ----- Original Message ----- 
  From: Zonn 
  To: vectorlist@vectorlist.org 
  Sent: Sunday, May 15, 2011 7:59 AM
  Subject: Re: VECTOR: 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
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      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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