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Not a signal to be heard here.? What are you guys experiencing?

I prefer units, such as the (tr)uSDX, which does not have a built-in battery. ?That allows me to plug in batteries of varying voltages to safely check the SWR of portable antennas (or operate QRPp at

In theory, an FET subjected to an overvoltage condition goes into Avalanche Mode Breakdown, which is a region where the FET functions like a zener, with a wattage rating equal to the FET wattage

I discussed with Ed Fong (WB6IQN) concerns about installing an internal battery on these radios. You don't want the biggest Li+ pouch cell that will fit. They expand 10-12% radially as they age. You

Doug, I assume you are talking about the USDX radio’s battery. The (tr)uSDX has no internal battery. A charger came with my USDX. Since it is charging 11 V battery, I assume it is feeding 11-12V. I

On another topic how do you charge the internal battery?? What size plug, what is polarity?

Keeps the SD junction? voltage below 60v limit.? Diode conducts at 47v

How does the diode protect against high SWR? What is the theory? Hiroki AH6CY by

It's the diode connected to the black connector at the top middle of the picture.? ?Do you see it now

good advice. Any chance you could resend one of those pictures with the component circled? that'll make it a little easier when I get home and dig through my 10,000 emails. If not, it's easy enough to

Connie and Hiroki,? it's a simple fix.? Just be sure to pay attention to diode band orientation.

Lower left corner.

I blew the BS170 final transistors (set of 3) twice due to inadvertent high SWR and had to replace them. Fortunately, the replacements transistors are inexpensive. Doug, when you say place 1n47576

Thanks for the tip– – I will look into this once I get back home. I'm glad I have a radio I feel comfortable just opening and modifying. 73, Connie W6EFI

Connie,? I? strongly encourage you to install a 1N4756A diode between rf and ground.? It will? protect your finals. Doug

*keenly lol

I am on the road right now, currently in a hotel in Tehachapi. Last night I set up my truSDX connected to a small MFJ16010 tuner, then tossed a wire out into a tree from my balcony, and dropped

I am following your adventures here, Kinley. Please keep us updated. I will probably copycat down the line.