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B&K 1075 TV analyst
I've had this for a while, and I finally got a schematic for it, so I started working on it. The schematic I found turned out to be quite different from the unit itself and wasn't much help. But I went and tried it as-is and the only major problems were the horizontal and vertical sweep rate. Seeing as it was mostly working, I just replaced capacitors without changing anything, and it worked after I changed a few caps. The only problem that remained was that there was no signal from the video output jack, which turned out to be caused by a shorted resistor.
The top of the chassis was pretty rusty, I cleaned it with naval jelly and lacquer thinner. It looks ok, but I'll probably go back and do it better later. The schematic I have must be for an earlier or later version of the 1075, either that or somebody made a lot of modifications. One major difference was that in the schematic the voltage for the photo tube comes directly off a tap on the power transformer, but in my unit it comes off of the flyback. The power supply circuit consisted of 4 of those selenium plate rectifiers in series and two .05 capacitors as filters and connected to the same tap on the fly as the yoke. I'm assuming they had to use 4 of them to increase the amount of reverse voltage they can hold up against? They were working, but I just don't trust those seleniums, and replaced all 4 with one 1N4007. Anyway, it's nice to have this thing finally working. I think I bought it back in the summer of 2009. I don't see many of these 1075s, the 1076 and 77 seem far more common. Anyone else out there with the 1075? Last edited by Adam; 07-17-2014 at 01:33 AM. |
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