QCX Absolute max supply voltage

scot forshaw

Hi Hans,

Hope you are well. My I have just put my QCX in a paraset style case for SOTA which I am putting a reserve battery in also.

My QCX is one of those perfect 5.1W at 13.8V (diode removed). The battery I am hoping to use is a 3A 4x3.7V Li-On battery which nominally will give 14.8 v but like most lions after charging it kicks closer to 16.9v for a while until things settle down. 

Not wanting to hurt my QCX at the moment I was wondering your thoughts on using that as is, or is it better to put a couple of inline diodes in there to reduce it to be safe? 

I'm assuming its the key shaper that gets the stick? I can heat sink that if need be.... Main issue is with only 3A to play with, once they drop voltage, the diodes would possibly prevent getting the best out of it. Didn't want the extra weight of building a regulator, but if thats what to takes I would.

What do you think?

2E0WWV ... oh her she is her new case :) 

Torbjorn Skauli

I run mine on a 4-cell LiPo, but with small heatsinks added to the 5V regulator and the PA transistors. Can't recall if I also changed the input electrolytic, check its rating. Have been running WSPR a lot, and it has survived fine so far.

Torbjorn, LA4ZCA