About Supergun: 1 KOhm resistor on sync pin?

[caius]

Hi all,
I found in this page:

http://geocities.ws/podernixie/htpc/...tml#jammascart

that a 1KOhm resistor is needed on the Sync PIN.Now, in my selfmade Supergun I don't have this resistor while I have the three 220Ohm resistors on RBG and I get perfect colours on my SCART TV and also sync is good except for some PCBs (bootlegs mainly) that roll up and down.For example I have a Pitfall II PCB which syncs well in a Sony TV while it rolls in a Grundig TV and in a Amiga monitor M1438s which is connected to the Supergun through a sync splitter (with EL4583 IC) since this monitor accepts only H and V sync.
So my question is:

Is that 1KOhm resistor really necessary on the Sync pin?What is its utility?
Thanks..


P.S.
Is it possibile to add some circuit to  adjust vertical sync on a JAMMA Supergun?I know on arcade monitor it's possibile.

[airthrow]

I've never had a resistor on sync on my superguns and they all synced fine.

[Hojo_Norem]

Some TVs (sometimes the older ones) don't like too much voltage on the sync.  I had trouble with a couple of old Philips sets.  One would roll when ever the screen went bright white and the other would actually trip its protection circuitry.  A resistor on the composite line (used for sync on RGB scart) seemed to fix the problem.  I cant see it doing any damage if you try

[NFG]

It's very common for arcade boards to overdrive the connections.  In fact, the majority of my PCBs put out too much power on the RGB and S lines, typically 1V instead of the standard 0.7V.  This resistor will certainly drop the voltage, probably too much, but a TV is much better at using low-V syncs than high-V.