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I have a first-run uBITX with the matching case.? I pre-ordered my kit before they were shipping.? The PCB says V3.? I've been very busy for the past year with work. I have some time now and plan to pull it off the shelf and bring it to my bench for updates.? Searching through the various threads related to mods is daunting. The only change I had time to make is a gain change to the mic input.? I'd like information please on bringing my board up to the current hardware release.? As a minimum, I want to flatten the output power across the upper bands.? I've also seen threads about reducing IMD but don't know if this is really necessary.? Can someone please point me in the right direction?

Also, I have aVU3SUA case that I purchased from HF-Signals over a year ago.? It includes a USB jack on the back and a TX/RX led on the front panel but I have no information as to how these might be used. Does anyone have information on a digital interface card that might connect here?

Rich KE1EV

Hi Rich,

You shouldn't go through the threads for the mods.? Go to the wiki here and check on the ones there.? I'd recommend this one first:

/g/BITX20/wiki/RF-power-and-gain

For harmonics, there are more options so it gets a bit harder.? There is the one on the wiki, but also others are doing external filters.? ubitx.net has more information on that.? They have organized information on flattening the band too, but it should be similar to what's in the wiki.

They might have info on wiring the LED and installing the USB cable on the case too, but I haven't looked.

73,


Mark

Rich

Hardware is more cumbersome to update than software. Also, the differences between v3 and v4 aren't huge. Mainly a different audio amp, I think. If your v3 is working, that is great.

All v3 and v4 boards tend to have spurious out of compliance, maybe v5 might also. Our local club kitted a relay board and a filter to address spurious, other possible solutions are out there.

Folk are experimenting with power flatness. For ssb it might lead to more trouble to try it. My v4isn't to bad in its behavior from more than 10w on 160m to around 4w on 10m. I think effort is better spent elsewhere for getting only a fraction of an S unit.

Enjoy your ubitx journey,? it's a cool rig.

Curt