Hi This is my post when i found the problem i was having,
Hi i found this when my FT817 did not output power on 2m and it was the Diode that had gone bad,
Good Luck, Dave 2E0DMB
so on Pin 8 of Q3003 on the PA Unit is a voltage called V-TX that
switches the output of the PA FINAL thru to the 2 Meter Low Pass Filter.
There it passes thru the Relay RL3001 which for 2Meter is closed from the
moving contact to the Normally Closed (Black) contact which passes the TX
energy on to the Diode D3003 an HSU277 ( Pin Diode ) and from there on to
the ?front or rear Antenna select RL3015.
Other than that, there is another Diode D3005, that enjoys going bad and it
can also cause the problem you are having.
These are both on the bottom (B side) of the PCB. ?This diode turns on to
protect the RX when TXing. ?This is turned on from pin 4 on the Q3003.
