Re: reviving my sbitx v3
开云体育
Evan,?
?Is it possible that R5 and R6 are mislabeled on the schematic? After I removed Q9,Q10,Q101,R5 and R6, to check continuity of pads and traces, I found that bottom of R6 connects to the gate-pin1 of Q10, not the source-pin3, and connects to the source-pin3 of
Q101 and not the gate-pin1, as indicated in the schematic. The schematic is from Farhans github, titled sbitx v3 production. Let me know, thanks!
From:?Michael Bales <mikebales73@...>
Sent:?Thursday, March 6, 2025 2:57 AM To:[email protected] <[email protected]> Subject:?RE: [BITX20] reviving my sbitx v3 ?
Yes, I was somewhat relieved that I am getting the proper Tx signal. I feel that I may need to remove Q9, Q10, Q101 and check the continuity, rule out damaged pads/traces, and swap in new components. Also when I mentioned using
through hole for Q10,Q101, I was thinking about using regular 2n7000 in place of the sot23 2n7002. Would those work?
-------- Original message --------
From: "Evan Hand via groups.io" <elhandjr@...>
Date: 3/6/25 2:07 AM (GMT-05:00)
Subject: Re: [BITX20] reviving my sbitx v3
Michael,
?
The TX signal works (recieve at 0.15 volts, transmit at 3 volts).
?
?
The pins on Q9 are marked in this photo:
?
The gate (pin 1) of Q9 should be higher, and the tab (Pin 2 or drain) should be 0 volts when receiving and close to 12 volts on transmission.? It could be a failed Q9, Q10, Q101, or combination.? I would start with Q10, as it should pull down the gate
of Q9 to turn it on and supply the 12 volts to the driver stages.??
?
?
Q101 is a 2n7002 MOSFET.? This can not be replaced with a 2n2219.??
?
?
The above is based on not getting 12 volts on the tab of Q9.
?
73
Evan
AC9TU
?
-- Mike - K8MCB? |