DT40 Pro tuning howto

[LASER-AD]

Hey Bill, I STILL need to get my 6800 scanners checked out and tuned, maybe new/better mirrors? When would be a good time to get you to do this? Thanks.... Also im thinking about making my qm2000 a qm2000.net... Is this something you would need to do, or i can add it on this end? Thanks for the info...Carey

[Pangolin]

WE don't charge anything for the mod. If you pay for shipping both ways, we will do the mod and return the scanners to you.

A few points. First, we treat the entire laser industry like a "Vidal Sassoon" advertisement. If you don't look good, we don't look good. Even if the laser shows are not made by our software or our products, if laser shows don't look good, it is bad for everyone. We have always had this philosophy, which is one of the reasons we do so many "free" things for this industry, including having our PR agency do all of the ILDA Public Relations of laser shows over the past two years, entirely at our expense.

Second, the mod involves mostly removing things... Unfortunately, some companies who are producing scanners don't really understand what each part does, or why it does it. It is mostly a "heard mentality" -- like "everyone is going this direction, so I guess we will go that direction too"...

One example of "heard mentality" on the DT-40 scanner amps is the notch filter. It was placed there by Jian because the Cambridge 671xx for their model 6210 scanner had a notch filter, so this must mean he needs one too, right?? WRONG!! The reason why there was a notch filter on the Cambridge model 6210 scanner was because, initially, Cambridge used a plastic "butterfly" for their position sensor on that scanner. This butterfly had a resonance at 18kHz, which is pretty close "in band" for 30K scanning and especially for faster scanning. So Cambridge made an 18kHz notch filter to help to remove problems caused by that resonance. BUT, the 6800 "clone" scanners made by Chinese companies don't have a plastic butterfly, or any butterfly at all for that matter. The position sensor resonance is smaller, and at around 30kHz, which is far enough "out-of-band" to not have to worry about it. And even if a notch filter was needed, another thing that would also be needed is the proper equipment to tune the notch filter (called a DSA) and only the biggest scanner companies (and Pangolin) have one of these. So, I have a philosophy. If you don't have the proper equipment to tune something, why tune it? It is sort of like trying to high speed balance the wheels on your car by mearly duct-taping fishing weights to the wheels and driving it around until it "feels smooth". Nonsense... (Incidentally, not even Cambridge uses this notch filter any more because they changed the material of the butterfly).

Also, the 6800-clones often have a "high frequency damping" and "low frequency damping". Although this is "double" the number of damping controls, the result is a servo that is 8 times as hard to tune (it's like a cube function). Also, again, since the resonances of the scanner are small and "out of band", the high frequency damping doesn't really buy you much in terms of performance. But what it does buy you is tremendous difficulty tuning, and most people (including some scanner companies) basically can't tune them. So we get back to my argument above -- if you have something that requires tuning, and you are not able to tune it, then why tune it?

So part of the mod a change in components and also removing the "high frequency damping" pot altogether, reducing the number of adjustments and also increasing performance. Plus, scanner amps that only have "servo gain" and a single "damping" control are really easy to tune.

There are a few other parts of the mod that increase large signal performance, but these are the main parts. Basically, simplifying things.

At Pangolin we are all of the time saying "less is more". Less features = less confusion. And less pots on the board also = less confusion and easier tuning, and ultimately better performance.

Best regards,

William Benner

[QUAZAR]

WE don't charge anything for the mod. If you pay for shipping both ways, we will do the mod and return the scanners to you.


Best regards,

William Benner

Very generous of you. Would I be correct in assuming a few beers and a box of cookies would be appreciated?

[Astroguy]

WE don't charge anything for the mod. If you pay for shipping both ways, we will do the mod and return the scanners to you.

A few points. First, we treat the entire laser industry like a "Vidal Sassoon" advertisement. If you don't look good, we don't look good. Even if the laser shows are not made by our software or our products, if laser shows don't look good, it is bad for everyone. We have always had this philosophy, which is one of the reasons we do so many "free" things for this industry, including having our PR agency do all of the ILDA Public Relations of laser shows over the past two years, entirely at our expense.


Best regards,

William Benner

Bill, You guys ROCK!