Stan, one of the reason that IRF fail with a huge current draw is casedby gate being disconnected or bias being too high.. Rv2/3 ground goingopen. On many of my experimental boars provided by

RV4 is the VOLUME control and in the diagram clip what you havehighlighted is RV1 the power lever set preset. RV4 is not shown in your V4 diagram. Raj At 16/11/2021, you wrote:

Rich that is the drive level to amplifier stages it can be adjusted up or down to vary the output. I adjusted it using the 40meter band and set it to get peak out and then backed it off a touch. I

I recently received a uBitx V4 kit that was 99% complete. It didn't take much to get it working, but now to get it working well... If I can get it operating reasonably well, I may pass it to my

Hi, Cw in the stock uBitX was not very good. Farhan has testified that he is NOT a CW op. In my case I installed the CEC software but I don't think that is the root of your problem. I think my

Ok, I see your idea, Sigi. Very good. When I burnt the trace I was using an ordinary 20a 13.8v switching supply. Now I have the radio on my workbench and I’m using an adjustable current limiting

Hi Dave, I could be barking up the wrong tree or even be in wrong forest but I recall something about requiring a 'stereo' plug on the cable from the straight key and it isn't wired like our legacy

But that doesn’t explain why a set of paddles works using the Dah key when the setup is set for “hand key”. It does work, just uses different connections so processor speed must be

wire the pa separate ... use for first smoke (bench) test a current regulated bench psu (either for onlys pa section or just for the complete rig) if current is too high (blown final or

hi Howard, The answer is no, there is not enough room in the KD8CEC firmware to allow for the screen painting that the stock display requires. The KD8CEC firmware works with one of the text displays

On Mon, Nov 15, 2021 at 03:32 PM, David Wilcox K8WPE wrote: Any ideas as to what the cause might be?From memory, this is a software issue combined with a slow processor (Nano). The software reads an

After looking over my new Version 6 uBitx and enjoying it I have discovered an issue regarding using a straight key. As I had mentioned in a previous email to the group when in “hand key” mode and

Thanks for the suggestions, Evan. It’s good to know about the file from VU2ZAP (great call!) and I believe I’m in good shape with the repaired trace. We’ll see… Thanks for comment Sigi.

Can the KD8CEC v1.2 firmware be used with the standard factory display in v6? I guess I can probably download the sketch -I should be able to tell from that - but I'd appreciate any information. I

if you can wire the pa with higher voltage i bet only the 12v rail is over power switch no bias (12v off) no current on 18v (or whatever) rail (voltage yes ... current no) dg9bfc

Stan, Also, I would be sure that you have repaired the short that burned out the trace before you try transmitting again.

Stan, Do a search in the files section of this list server for vu2zap. Raj recorded measurements of the transistors, not the test points. It is for a version 4 uBitx, but other than the first IF

Thanks, Dave. The process you describe is what I found on the HF Signals website. I guess setting up the PA Bias is my next step. I’m still very interested if anyone knows of a listing of what

It's likely not the case but I'd hook a basic DVM up to the load you used and ensure there's not a short or something there. Highly unlikely but why take chances?

Thanks for that info. I personally, would like to see the power to the finals split like in the old days when you could feed the radio with 12 volts and the IRF510 with a higher voltage. I couldn't