Hi,
Sorry, I was waiting to see if you would try some of the changes. I have updated some details based on your post on May 15 2010.
Just try the following changes (one at a time?) and see if things improve for a 2 Watt version first
1. Attached are two transformer re-designs using your available cores. Wind them with the maximum wire size that will fit.
2. Dont use C4 or C5.
3. Boost Vcc to 15V.
4. Put 1Ω resistor in the sources.
5. Bias the MOSFETs no signal current at ~50mA.
6. Connect gate drive and voltage bias as shown.
7. Use the IRF640 for now. Are you able to get IRF510??
8. Leave the M1 drive circuit as is for now. It may work well enough for your requirements.
9. Let us know how the test goes.
Are the oscillator and modulator located on the same PCB as the linear amp? If so, then we could use the differential drive from the MC1496 later if required.
Good Luck,
Ifixit
Sorry, I was waiting to see if you would try some of the changes. I have updated some details based on your post on May 15 2010.
Just try the following changes (one at a time?) and see if things improve for a 2 Watt version first
1. Attached are two transformer re-designs using your available cores. Wind them with the maximum wire size that will fit.
2. Dont use C4 or C5.
3. Boost Vcc to 15V.
4. Put 1Ω resistor in the sources.
5. Bias the MOSFETs no signal current at ~50mA.
6. Connect gate drive and voltage bias as shown.
7. Use the IRF640 for now. Are you able to get IRF510??
8. Leave the M1 drive circuit as is for now. It may work well enough for your requirements.
9. Let us know how the test goes.
Are the oscillator and modulator located on the same PCB as the linear amp? If so, then we could use the differential drive from the MC1496 later if required.
Good Luck,
Ifixit
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