C
Clifford Heath
Guest
On 18/04/14 04:09, Jim Thompson wrote:
No, but if it's a clue, I've seen it used as a place to control the
gain. In particular, the G3ZOI 2m ARDF receiver allows these pins to
rise more than one diode drop above ground to reduce gain. (I think,
without checking the TA7613AP data sheet).
<http;//www.open-circuit.co.uk/download/rox2t-v3-dia.pdfâ>
Does that help?
Oh, and the BF904R was used in HF for low IP3, but wasn't the
exceptional transistor - I was thinking of the 3SK299, along with
similar obsolete devices like the NE25139 and NE25339, all of which only
exist as counterfeits, it seems.
I'd still be interested in how the BF904R works.
On Thu, 17 Apr 2014 12:14:15 +1000, Clifford Heath
no.spam@please.net> wrote:
SA612/SA602. There are models around, but I have no way of knowing how
good they are.
Nothing on the data sheet tells me the voltage on pins 1 and 2, just
shows a block called "bias".
Can you provide those numbers?
No, but if it's a clue, I've seen it used as a place to control the
gain. In particular, the G3ZOI 2m ARDF receiver allows these pins to
rise more than one diode drop above ground to reduce gain. (I think,
without checking the TA7613AP data sheet).
<http;//www.open-circuit.co.uk/download/rox2t-v3-dia.pdfâ>
Does that help?
Oh, and the BF904R was used in HF for low IP3, but wasn't the
exceptional transistor - I was thinking of the 3SK299, along with
similar obsolete devices like the NE25139 and NE25339, all of which only
exist as counterfeits, it seems.
I'd still be interested in how the BF904R works.