In the x6100 the supply voltage is NOT reduced before going to the finals and so the previous comments are both true and untrue. 12V into the radio = 12V onto the final FET. That is why it needs 12V external for 10W... I personally think hacking the firmware to make it look like 10W on the battery is a stupid stupid idea that will result in tears. The CPU and circuits do indeed drop the battery (or external input) voltage to the required levels for the various circuits, 3,6, 5v,8v etc BUT the RF OUPUT FET is directly coupled to the battery/or external voltage. The output FET used in the x6100 is the sane as the one in the ICOM 705 and is rated to 30W and excess of 40 Volts, with a. working case temperature of 150 oCelcius so the 5-10w we throw at it is well within design range. The cooling for the FET may however leave something to be desired.
Running 10W on ANY passive cooled radio will result in a warm case..
By far the worst offender and the one thing that manufacturer says is DO NOT CHARGE AND TX .. the charger will then have to dissipate the 3-4amps you are drawing and it is not cooled. This is pretty obvious pretty quickly.
I read so many assumptions and statements about case cooling. That cooling the case won't cool the battery, or won't cool the finals... the finals are buried in the middle of the radio! ?
All heat removed from the case/body/finals is REMOVED and WILL contribute to cooling the finals. That is physics not assumptions. What is not clear is how much passive cooling is needed for a lunatic to think that he can drive it at 10W FT8 duty for 12 hours.?
The radio also sports a LDMOS MCP temperature sensor in the output stages. There is a lot of extremely good features in this radio...
Worth remembering .... the output RF stage is a LINEAR AMP.. There is a minimum current draw due to biasing and the class of amplification employed.
