FT-857 LiPo Batteries (again) - A new possible solution

[GM4LLD]

Here you go…

@GM4LLD

Disaster #2! Plugging the coaxial power lead I found the tip (+ve) is exposed and it touched the metal case of the transverter. Click. 817 went off. Oh dear. Hacking the cables to get both working the absence of two batteries meant there was an unfused path. The +ve of the battery lead was connected to the case of the transverter. The -ve wasn’t connected but the IF lead connected the -ve through the screen. That screen will carry a lot of current. The fault current makes its way across the 817 circuitry to the -ve cable at the 817 to the battery and ker-boom! The classic failure is the common mode choke melts and a track by the power socket lifts.

“Those who cannot remember the past are condemned to repeat it.” – George Santayana, The Life of Reason, 1905.