C
Charlie+
Guest
Im repairing my ~1970s 50MHz b/w Telequipment D83 oscilloscope
mainframe (Telequipment is out of business now). I have got it back
working pretty well after Power supply and EHT faults. The plugins
are fine.
However the blanking return at high speed sweep ranges is not working
as well as it should. I have all the manuals but some of the
transistors are probably not as specified in the manual and some of
the transistors inserted are not in any databases I can find.
Can anyone kindly shed light on any of these?
Manual Inserted
BF305 Si NPN FRB 749
Comments: The BF305 is a well known transistor but
FRB 749 - I cannot find anything at all. Package is the brown
elineT092
Manual Inserted
T0203 Si PNP 0404 M251 (Package TO92)
Comment: Cant find a sausage on either of these! The M could be for
Motorola and this seems to have gold plated leads and could be some
sort of military spec version of something perhaps?
Manual Inserted
E1530LL Si NPN TI 0310-00 D8041 (Package TO39)
Comment: This should be a matched pair in the final Y amp drive but
the gains certainly now dont match at all - so I need the spec and I
cant find anything under either of these numbers.
Grateful if anyone can help! Its annoying to repair and then not have
it working perfectly!
Charlie+
mainframe (Telequipment is out of business now). I have got it back
working pretty well after Power supply and EHT faults. The plugins
are fine.
However the blanking return at high speed sweep ranges is not working
as well as it should. I have all the manuals but some of the
transistors are probably not as specified in the manual and some of
the transistors inserted are not in any databases I can find.
Can anyone kindly shed light on any of these?
Manual Inserted
BF305 Si NPN FRB 749
Comments: The BF305 is a well known transistor but
FRB 749 - I cannot find anything at all. Package is the brown
elineT092
Manual Inserted
T0203 Si PNP 0404 M251 (Package TO92)
Comment: Cant find a sausage on either of these! The M could be for
Motorola and this seems to have gold plated leads and could be some
sort of military spec version of something perhaps?
Manual Inserted
E1530LL Si NPN TI 0310-00 D8041 (Package TO39)
Comment: This should be a matched pair in the final Y amp drive but
the gains certainly now dont match at all - so I need the spec and I
cant find anything under either of these numbers.
Grateful if anyone can help! Its annoying to repair and then not have
it working perfectly!
Charlie+