Favorite jellybean ~HF BJT?

[Tim Williams]

2N2369 is an old standby... kind of high current (200mA), like a '3904 sped
up about 2-3 times. Not well specified though, I suppose because it's so
old. I'm thinking in the 20V, 50mA range, fT maybe 0.5-1GHz. Like if you
wanted to make old school RTL circuits that run as fast as 74S TTL. MPSH11
looks good, and '81 looks like its complement. I've used PN3563 before
(complement PN4258? unobtainium?).

Any favorites?

I'm not looking for SMTs or anything over 3GHz. I'm still exploring the
through-hole era, where it helps if the transistor doesn't oscillate on its
own legs.

Tim

 

[Tim Williams]

2N2369 is a GOLD-DOPED device designed primarily for low-storage-time
switching

Yup.

Is that all you had to say, your sentence seems to end suddenly?

What's your favorite, Jim? And don't say InP monolithic, because that
doesn't count. ;-)

Tim

 

[Tim Williams]

BFR91, 20V Vcb, but only 12 V Vce, 50 mA, 2GHz.. low Ccb .5 pF, Cce .3 pF
can be used trough hole and surface mount, seems stable here....

Ewww, TO-50. Hmm, Vishay claims 5GHz, planar ground a must. And like most
RF parts, it lacks DC parameters...

Yeah, stable at what frequency and bandwidth? 800MHz, or wideband? ;-)

Tim

 

[Joerg]

2N2369 is an old standby... kind of high current (200mA), like a '3904 sped
up about 2-3 times. Not well specified though, I suppose because it's so
old. I'm thinking in the 20V, 50mA range, fT maybe 0.5-1GHz. Like if you
wanted to make old school RTL circuits that run as fast as 74S TTL. MPSH11
looks good, and '81 looks like its complement. I've used PN3563 before
(complement PN4258? unobtainium?).

Any favorites?

I'm not looking for SMTs or anything over 3GHz. I'm still exploring the
through-hole era, where it helps if the transistor doesn't oscillate on its
own legs.

Well, not much to write home about but slim pickens if you don't want SOT23:

http://www.fairchildsemi.com/ds/2N/2N5770.pdf

Characteristics similar to:

http://www.fairchildsemi.com/ds/MM/MMBT918.pdf

 

[Joerg]

I like BFS17. It plenty fast but not so fast that it oscillates all on
its own, like many parts do. It is surface mount, which keeps the
parasitics down.

I always keep a (large) vial of those in stock here, just like we do
with Sierra Nevada Pale Ale. Not sure why Tim absolutely wants
thru-hole, SOT23 is easy to solder onto experimental board. Problem with
thru-hole is that anything fast almost needs to be soldered down with
its can like they did on old UHF tuner. And the market for that stuff is
gone.

BFT25, Phil Hobbs' favorite transistor, is remarkable too.

That one is pretty low noise but at 20 cents incredibly expensive