I am not expert but it only took me 30 minutes in my yard to master it.
Problems with DF tracking in this day an age. 1. Cost. Price the purpose built DF rocket/falconry trackers. Pretty close to a GPS tracking system.
2. Sight unseen? One better get a decent bearing fix or if not, could be SOL if they aren't able to get within the ground footprint of the tracking transmitter.
Ok, if one goes the ham radio route, they can study up and build/cobble together an economical DF tracking system. A Beeline DF tracker with a ham radio H/T, $20.00 attenuator and an Arrow Yagi or homemade antenna.
In fact I went the Ham route in 2007 because APRS/GPS trackers were close to a commercial DF setup. Then again, it was $900.00. Enter in the EggFinder GPS system and the cost is 16% of that for a GPS setup now.
As mentioned, DF trackers are smaller and can fit in smaller rockets but you do one GPS recovery of a nominal sight unseen flight and you'll try to figure out how to fit GPS trackers in all your high filers. The longer they're out of sight
the greater the chance you won't know where to go without a visual on descent.
Your 29mm? Do the DF tracker and Chuck is absolutely right, it's easy to master as long as you are aware of the phenomena of antenna polarity and attenuation of the signal at the receiving end to maintain the directivity of the incoming signal.
I've had nine totally sight unseen GPS tracker rocket flights with one ballistic recovery like I showed in that link above and 6 of those 9 recoveries would likely have been doable with DF tracking but would have been a bit more "uncertain".
The ballistic recovery would have been totally impossible with a single DF receive station as the tracker died after it hit. Trying to keep a bearing lock on a dead tracker is nearly impossible unless one had a visual on the descent.
Kurt