TO92 marked F422 = BF422 ?

[N_Cook]

I'm aware that in some situations TO92 transistors marked C556 mean BC556
(not 2SC556), can the same be for BF...?
I have a board with dozens of BF422, HV transistors on. These agree with the
schematic but someone has previously replaced 2 with a pair marked F422 and
one of them has failed B-C-E short. Diode testing (Vb-c < Vb-e) the
remaining one shows correct pinout for BF422

 

[ian field]

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:i2e3d6$hlp$1@news.eternal-september.org...

I'm aware that in some situations TO92 transistors marked C556 mean BC556
(not 2SC556), can the same be for BF...?
I have a board with dozens of BF422, HV transistors on. These agree with
the
schematic but someone has previously replaced 2 with a pair marked F422
and
one of them has failed B-C-E short. Diode testing (Vb-c < Vb-e) the
remaining one shows correct pinout for BF422

That marking style is fairly common.

 

[N_Cook]

ian field <gangprobing.alien@ntlworld.com> wrote in message
news:8i13o.319199$k15.160568@hurricane...

"N_Cook" <diverse@tcp.co.uk> wrote in message
news:i2e3d6$hlp$1@news.eternal-september.org...
I'm aware that in some situations TO92 transistors marked C556 mean
BC556
(not 2SC556), can the same be for BF...?
I have a board with dozens of BF422, HV transistors on. These agree with
the
schematic but someone has previously replaced 2 with a pair marked F422
and
one of them has failed B-C-E short. Diode testing (Vb-c < Vb-e) the
remaining one shows correct pinout for BF422


That marking style is fairly common.

I don't remember coming across it before for BF... , a few times I've seen
it with Philips TO92 BC... types