Guess what? I already have a smoker. and it's an (as you say) ECB. (El Cheapo Brinkman). The green "Gourmet" smoker. I have had it for about 15 years and have used it once. I forgot about it and just now remembered it was hiding in my storage shed. Needless to say it wasn't in the best of shape. I had to use a lot of wire brush to it. to get it ready for another try.
Let me explain my first attempt 15 years ago..... first of all I knew nothing about smoking meat when I first used it. My extent of knowledge was get the coals burning and let it cook for 4-5 hours. My Tri-Tip almost came out as Beef Jerky. It was pretty close.. That is pretty much why it sat for 15 years.
Then I discovered this site which rekindled (so to speak) my interest in slow cooking. So I decided to try again with another Tri-Tip. Wow---what a difference a little knowledge makes. I really didn't have time to marinate the Tri-Tip so I just used Jocko's Santa Maria seasoning on top of Olive oil and I added a bit of finely ground Decaf Coffee right before I I started ..
I used a chimney coal starter with Kingsford Briquettes. I got them going and spread them in the coal area along with Whole oak charcoal on top.. They were all burning and I put on the Tri-Tip.. It stayed mostly in the lower part of Ideal range then after a while it started creeping into the warm range. this started to concern me so I added a few more Briquettes and whole oak charcoal chunks. This seemed to stabilize things so I was happy. . I was still unsure what the temps were so I pulled out my $16 wireless remote thermometer. It at least let me know which direction the temps were going. I set it for Medium (145) and it pretty much stayed at 143) I wasn't too concerned at the higher temps as I was not expecting the perfect Tri-Tip for my second try.
After approx 2 hours, I took it off and tented it for about 1/2 hour.. It turned out maybe a tad cooked too long but the flavor was Excellent and the meat quite tender.. Over all good effort.
Sorry I don't have pics. I really wasn't expecting much----Next time---Defo!!!! Bye the way, 4 hours after I took the meat off the smoker, The Charcoal was still putting out the heat