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A friend of mine bought an SMIQ-03b on a whim, we've replaced the mmic amplifier chip that seems to always fail, now we're trying to figure out why the ALC doesn't work. It generates signals just fine, but the fine attenuation does nothing.

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Yeah that pretty close to some problems I'm working on with mine. It has an "IQCON ALC loop failure" and claude was able to diagnose that the 2013 rail is around 11.44v (outside of the 10v range iirc) and the 2015 one is zero instead of the min of 0.13v. The RF paths looks mostly healthy as far as we can tell but I've only tried 10db steps and it seems consistently 4-5db low, assuming I'm using my oscope right.

Which MMIC did you replace? And what errors did you see? I have 110 and 111.

I'm not sure which he replaced, but having started trying to grok how it actually works, it's chock full of HFET and other amplifier chips, and over-stressed RF switches.

I'll report back if we ever get it actually working properly.

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