Hi, welcome! :-)

Something you can try:

1) place a ferrite bead on the base(s)

2) Toss a low value resistor (10 ohms or less) on the collector as close
as possible to the transistor.

Good luck!

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca