Transistor Equivalent

[Med-Tech]

Hello, quick question. I am looking for an equivalent Transistor for a 9Bt. Not been able to find anything of use online, therefore I m reaching out to you all. I have found this 9bt is a MMBTRA109SS.

Thanks for looking and assistance.

[stj]

search local sources,
those are usually called "digital transistors" or "pre-biased transistors"
a common type starts with DTA
the datasheet says the 109 is using 47k and 22k resistors

[truclacicr]

9B* = PMMT591A

https://www.mouser.com/datasheet/2/916/PMMT591A-2938678.pdf

https://www.amazon.ca/pcs-Transistor-PMMT591A-SOT-23-SOT-23-3/dp/B0973VVTWT (photo)