Dear friends, have you any ideas about making low pAg gelatin emulsions (silver excess emulsion)?

All my efforts are unsatisfactory up to date. Best of my results is the emulsion that remained unveiled some hours only. It was making according to this recipe (100 ml):

Solution A (60 deg):
- water 60 ml
- 1M HCl 2 ml
- KBr 2,2 g
- KJ 0,08 g
- Inert Photograde Gelatin Rousselot 8 g

Solution B (room temp):
- water 40 ml
- AgNO3 4,0 g

Synthesis - Sol B pour in Sol A in 4 doses:
- 1/4 at once and 7 min mixing (at 60 deg)
- 1/4 at once and 7 min mixing (at 60 deg)
- 1/4 at once and 7 min mixing (at 60 deg)
- after cooling the emulsion till 46 deg the last quarter of silver nitrate pours in synthesis volume (AgHal microcrystalls charge exchange) and following 5 min mixing (at 46 deg)

After jelling, washing, remelting (at 35 deg), coating on glass plates and two hours drying such emulsion kept unveiled only some hour. I suppose that the main course of such instability is high pH of finish product - after washing ph of emulsion increase upto 4,4. It seem to me that pH = 4,4 is too high for long keeping of low pAg emulsion without to be veiled (even though the very good quality inert gelatin was used). Have you any ideas on this issue?