7189-A Caution!

[TerrySmith]

I was looking at spec's on 7189's in my GE book and noticed something weird. 7189-A has a different pinout (9LE), than 7189, EL84, etc (9CV). Pins 1&2 and 6&9 are connected together. So if you use pins 1 and 6 as tie points, you'll have problems. :angry4:

Are pins 1 and 6 connected on the DIY boards? :?:

[Shannon Parks]

I was looking at spec's on 7189's in my GE book and noticed something weird. 7189-A has a different pinout (9LE), than 7189, EL84, etc (9CV). Pins 1&2 and 6&9 are connected together. So if you use pins 1 and 6 as tie points, you'll have problems. :angry4:

Are pins 1 and 6 connected on the DIY boards? :?:

Pins 1 & 6 <aren't> connected on the diytube ST35 boards.
Looks like you get an extra 10% plate dissipation with those 'A's, too.

Shannon

[Uncle Ned]

I was looking at spec's on 7189's in my GE book and noticed something weird. 7189-A has a different pinout (9LE), than 7189, EL84, etc (9CV). Pins 1&2 and 6&9 are connected together. So if you use pins 1 and 6 as tie points, you'll have problems.

On the pinout for EL84, all the unused pins are marked "IC", "internal connection",
which is JEDEC-talk for "Don't use these for tie points"

7189A has a bit higher Pd rating solely because the Pd is rated under the
Design Maximum system rather than the more conservative Design
Center system. Physically, there's no difference, all other things being equal.