I tried cold smoking just yesterday with some salmon. I used a coarse hardwood sawdust with the screen in the wood box. At 140+ it did smoke a little but I was looking for lower temps and got it down to 120 +/- and at that low of a temp I got no smoke at all so had to use an external generator.
Roger from NJ
Are you making cold-smoked salmon or hot-smoked salmon? Lox would be cold-smoked and is not cooked. If the salmon is "cooked", then it is hot-smoked salmon, and the process is actually a low-temp smoke (not a cold smoke).
For true cold smoking, you want to keep the box temp below 100 degrees, below 90 degrees even better. The smoker needs to be set to at least 150+ for the element to be on long enough to get smoke going. If you want to cold smoke using the element and chips in the smoke box, then you will need a cold smoke plate. Or you can cold smoke without using the element, and use an AMNTS or external smoke generator (which you already have) with ice frozen in 2 liter soda bottles.
If you are actually "cooking" the salmon (hot-smoked salmon), you are actually doing a low-temp smoke. You don't need the cold smoke plate. Try setting the temp to somewhere between 160 and 180 (so it will generate smoke). Probe the thickest piece of salmon and remove when it reaches 130-135. It won't take long. Probably an hour or less.
It also depends on whether you have a D model or not too. With the analog controller, I do a 15 minutes on at full blast, 45 minutes off process to control the temperature and smoke production for cold smoking. It is helpful if you could put your smoker model in your signature line so we know how to be more specific with advice.