The Amplifone Registry thread.

[mcandrewsoun]

Probably the difference in failure rates is due to the LV supply not being in the Amp deflection circuitry. Apparently it really isnt needed, and most of the 6100 failures I see are LV supply related. Im intrigued by the slew rate difference.. Since slew rate is generally voltage per sec or (msec). I saw Ferro magnetic mentioned above..Are you talking about the Yoke? I could see some degradation of slew rate with coupling caps..but it really on comes into play on the output stage,since thats where the big voltage swings are, and it appears to be DC coupled. Its been many years since I took circuit design in college, so I maybe remembering some of this wrong..LOL..

What makes the HV supplies so unreliable? Seems like it actually does less work on a vector HV section then a Raster, since the HOT doesnt actually drive a yoke..

Andrew

 

[VectorJunkie]

Aside from the HV unit, I have seen way more component failures on 6100's than on Amplifones.

I would agree with this in part because there were way more 6100s out there, and what 6100 didn't have a problem in the LV section? My 6100 died in my Space Duel and that is how I found KLOV.

I have yet to even see an Amp in person. Btw - can one of you guys tell me the tube number of a 25" amp?

 

[jonathan1138]

I have been wondering lately just how many working Amplifones there are out there. I am thinking of collecting some data and making an Amplifone registry. There are probably way too many to list, but even in the group on here I would be curious to know how many we have. I am mainly concerned in actual complete working ones , but if you want to list a non-working one, that is ok too. I was thinking of a format that breaks it down by game and cabinet style of the game. You can list SN's too if you want.

Star Wars upright , SN 28, working
Deflection board SN unk.
HV board SN UR00028
Tube SN UR00028

Tempest upright , SN 02365, working
Deflection board SN UR05761
HV board SN unk.
Tube SN UR05726

If you are running an aftermarket HV or Deflection board just put aft. next to it. If you do not know the SN just put unk.

Hi - excuse me if i am quoting some of these wrong, or if they dont matter (i am sure the SN matters, but not sure what the XY is):

Star Wars Upright, SN UR02345 / XY # 27900
Deflection board - SN SD00600 / XY # 10839
HV Board - SN unk / XY # 12726
Tube SN UR09367 / XY # 21300


(Tube has date of Sept 15, 1983, has another date: June 23, 1983, shift 3, 3921).

 

[Level42]

What makes the HV supplies so unreliable?
Andrew

Well the HVT itself was simply poorly (but proudly) "made in the US"

Amazing that there are still people around who don't know the story about the "dead-red" HVT

Do some googling about Amplifone HVT or Amplifone flyback....

The funniest (but very unlikely story) is that of an Atari executive triggering a sprinkler to be the cause of the bad potting of the HVT's....

However, the HVT on Star Wars IS overstressed at the Death-star explosion by purpose of the designers. (to make it to defocus).

If you want to know the details, check out Jed Margolin's website: www.jmargolin.com

Here's a quote:
In order to have the Death Star explode the way we wanted it to, it wasn't enough to draw lots of concentric circles. We wanted to defocus the beam to fill it in. We briefly considered adding a vacuum tube to the monitor to control the Focus Voltage. Fortunately, the lead time for the part was too long. So what I did was to give the Vector Generator the ability to overdrive the monitor's color inputs. Overdriving the inputs causes the CRT to draw more current than it normally uses and drags down the High Voltage., which changes the normal ratio of Focus Grid voltage to Anode voltage, which defocuses the beam. This relationship is explained in The Secret Life of XY Monitors.

So maybe, just maybe, it was the designers fault that those poor red Amplifone HVT's all died....maybe Amplifone delivered exactly to spec but they didn't tell them about the overstressing....ha !

The issue that I now have with my Cinelabs HVT is that it actually DOENSN'T defocus at the Death Star explosion....but that maybe just adjusting everything better....