The Defpom Forum, for RadioMods, S&M Software and Music by The Defpom

Hi all,
I have new Stryker 440hp that I need to get the carrier down to a .5 to 1 watt. Preferably .5 watts without killing the overall power of the radio, keep modulation slightly below 100%. Is this possible with the new IRF520 Fets? I do not have VR16 on the board. Just VR13 High power carrier adj and VR21 Low power carrier adj which will allow me to get the carrier down but the it brings the overall power down killing the modulation lol. I do not want to disable the AMC limiter just keep max power with a lower carrier. Thx for the help!

It depends on the modulation scheme. Most modulate on AM by changing the drain voltage - as you found out, you can only go so low before it drops out completely.
It can be converted to low level modulation, allowing the drains to have the full supply on them - this will let you go down to 0.05W or even lower and still sound reasonably good.

However: This is a mod for a very experienced person. It involves changes to the AM/SSB switching, balanced modulator, audio limiting circuitry, output stage biasing, TX/RX switching, and the internal power supply. I've only ever done this once or someone who insisted, and it cost them nearly as much as the new price of the radio!

You would need to have a good reason for such low power to go to all that trouble.
If it's to drive an amplifier, much easier to reduce the gain of the amp...

Sue