Just wanted to touch on this thread again since I've been messing around with practicing to a fixed drone and to share my experiences.
To start, this is completely subjective since I am a DB novice but my ears are so-so because of so much music I've played in the past that is non-jazz. I'm doing this PIZZ-ONLY. My teacher hasn't had a chance to teach me any arco technique yet. I'm looking forward to it to compare with these experiences.
Anyways, I took one of Ed's suggestions and tried changed the droned pitches from time to time as I work on my Simandl etudes, instead of droning the root or in unison with a scale. I'm too lazy to program something to keep changing the drone tones while I'm playing. Instead, I've been using this little quirk (or maybe it's a feature) in Band In A Box. All you have to do is click on one of the notes on the virtual keyboard and drag up to the top of the screen. This will keep the note playing until I hit the keyboard again with the mouse.
I'm still running a chromatic tuner while I'm doing this and look at it sometimes to check how close I get, if the tuner can register quick enough. I'll notice that I'll be really off with one particular note. I'll change the drone to that weak note and keep practicing to hopefully improve my intonation on that particular note, sometimes stopping to check and adjust until I get the right intonation using the tuner to help me. A couple things I've noticed:
1. My intonation on those weak notes are improving with practice (only to be expected). This morning I noticed that I was the closest ever (maybe 5 cents off or dead on) when practicing in half-position.
2. Droning on the root really doesn't help all that much. I'm still off on other tones, especially 4ths. Similar with 5ths. I prefer drones on the 3rd and 4th (is that strange?) where it seems to help my intonation the most.
3. Playing an etude and droning on other tones is interesting experience. I still keep the sound of the root in my head but I seem to feel more 'comfortable' with these other tones. 7th's have a tendency to throw me off initially. Seems to be the hardest one to feel comfortable with, maybe because it's so close to the root.
4. Seems like my intonation is the best when I go with 'the force' and don't look at the tuner or fingers. For example, if I first strike the note and it's off, I dont' depend on the tuner to slide into the right place... I go by my ears and 'feeling'. When I look up to verify, I'm nearly on it so it's good to know that my ears are really helping to correct my fingers if I miss the right spot from the beginning. But my ears aren't always consistent if I'm really close at first. If i'm far off on first strike then everything works well and I slide into place just fine.
So far the results are pretty good. I only do this type of thing when practicing simandl most of the time. When I'm practicing other stuff, I focus on that and turn the tuner off. I've been using BinaB just for a drum track, and maybe some piano/guitar comping to practice walking. The soloing/strings comping gets annoying and I tend to ignore it after a while so I turn it off.
During last weeks lesson, my teacher was pleased and told me that my intonation was very good.

I totally wasn't expecting that at all and thought it wasn't all that great. Looks like i'm doing something right.
Comments or suggestions?