cmayna is giving you some great advice as well as others on the thread. Did you let the fish dry in the fridge overnight or out on a counter at room temp? I typically only dry mine for 1-2 hours with a small electric fan if I'm in a hurry. I don't wait until it is completely dry on the outside either. I like what cmayna said about batch size. I think the most I have ever done in my big chief (I have the front load version) is maybe around 8-10 pounds at a time. Granted it can do more but I started with very small batches (maybe 3 pounds of fillets) at first until I developed the level of smoke and flavors that I wanted.
I just re-read this from your last post:
i think we did everything right. the last batch of fish tastes good but it's so dang dry.
when we had the fish processed professionally in alaska it was moist-no hard outter shell. it tasted slightly smokey (we had some done with garlic/pepper, some cajun).
the fish we smoked ourselves is more like "squaw candy"-it has a hard outter shell, semi-dry meat. it's tasty ( i added cayenne pepper and garlic to the brine) and then added additional lemon pepper to some pieces, montreal steak seasoning to other pieces, and left some without additional seasoning. i even experimented by putting in two pieces without brining at all. it still dried out.
i used a regular meat thermometer and cooked unitl IT was 140-145 (it was hard to tell since the tails are so small).
however, we also smoked the bellies and they are juicier (more oil in them ) and moister.
It sounds to me like maybe what they did in alaska was a quick hot smoke of the salmon. The fish that I smoke have a somewhat hard (I would think firm would describe it better) outer shell and the inside is flaky and moist. Less so than if I had baked or grilled some fillets. I hope you don't give up yet. There is still a lot you can do with a big chief. Makes great jerky and smoked cheese in my never to be humble opinion.