Scott,
Here's a report from Allison regarding two IRF510's operating in push-pull
on 28v giving 50 Watts out.
They have survived years of abuse, including shorted antennas.
I sincerely doubt shorting the antenna on your uBitx with a 12v supply will cause any damage.
? ??
/g/BITX20/message/55159Jerry, KE7ER
On Fri, Jan 1, 2021 at 10:13 AM, Jerry Gaffke wrote:
I haven't tried shorting my antenna,
but I don't recall any reports of uBitx damage due to such a short.
The only issue I see is heat internal to the IRF510.
Each IRF510 is only on 50% of the time, that helps.
I suspect that with a 12v supply, the load presented by T11 and the LPF's and the board traces
would keep the drain current down to where the IRF510 die can transfer ithe heat out to the tab.
And would expect it to take at least 15 seconds for the tab and heatsink to overheat.
Perhaps a shorted antenna never does damage the IRF510's if there is some air flow on the heatsinks.
I could be wrong.
Perhaps others have more information on this.
Jerry, KE7ER
