Hi Paul
Great to hear you have made progress with the instabilities.
On looking back at the forum messages I gather that you have built the Linear amplifier with three RD16 mosfet devices ?
If so be careful with excessive gain in the transmit stages, the HF linear with three RD16's has more gain than is needed. Q13 (2N5109) produces around 400mw output which makes the 1st RD16 driver somewhat redundant!??
The 2N5109 in conjunction with just the two final RD16 devices should produce around 8 watts.
The original 3 X RD16 HF amplifier was designed for the MK1 transceiver and the standard BitX transceivers that did not contain the 2N5109 driver on the exciter PCB.
To clarify the Linear amplifier with 3 X RD16 can be used with the G6LBQ MK2 Exciter but the RF from the exciter must be reduced, the original linear amplifier PCB contains a PI network attenuator before the 1st RD16 and this must be used to avoid instability and overdriving the amp. In reality this is a waste of energy but some builders have used the extra gain to push the output above 10 watts but you then have to question the transmit linearity!.
Regards
Andy G6LBQ
