Vince wrote:
What danger, if any, is there when resonant 40m, 30m, and 20m dipole
elements in parallel with RG58 coaxial cable feed and the radio's
internal ATU are used on the 17m, 15m, 12m, and 10m bands?


The ATU permits loading of the non-resonant bands to full RF output,
but I have had a blown capacitor that is used within the LowPassFilter
for the 40m channel and another capacitor blown within the 12m/10m
channel.


73, de ~ Vince ~

Hi Vince, do you know if the caps in the filters blew while the ATU
was in the process of "tuning"? Or did they blow during normal
operation after the ATU had already "tuned"? The filters should see
their designed for impedance after the ATU successfully "tunes" to your
antenna system impedance. The filters will see all sorts of impedances
during the tunning process, and this time the caps in the filters will
be under the most stress. Another could be a connection problem in
your antenna system causing the impedance the ATU sees to change
intermittently.
My xcvr instruction book says use the lowest possible rf output power
setting when using the internal automatic antenna tuner.
Gary N4AST