About the 12mhz spur, the trap I believe is not that simple. Please let me know a good design without affecting the 30 and 20m bands. Checking it on my SDR receiver is really very low.

The KL203 senses the RF and less than 1w average power is needed. That is why it works as is with a softrock in AM FM and likely in CW. In SSB the average power is far less as in most transceivers unl

The KL203 is a tabu in the ham community. Don't even think to add in parallel or replace C14 with a 500V 1000pf.

The AN762-140 should be a good amplifier, I think it was described so in the ARRL 2010 Handbook. It needs lowpass filters like those Communication Concepts sells. It seems not overly complex to build.

Rechargeable AA batteries are nominally around 1.2-1.25v, 6 of them would provide 7.2-7.5vdc. Would it be too low?

I am looking forward to receiving my Antuino :) I guess I would power it with rechargeable Eneloop AA batteries. I think that keeping the voltage at 8 or 9vdc would keep it without overheating if used

That's very strange you changed so many mic elements. I haven't used that as much as you but I thought an electret could last decades. Are you sure the resistors supplying the elements have the correc

Regarding the spurs in ver3 and 4 I found that the solution by Farhan helped. If it not enough, for the 10m SSB (there is no spur issue for CW) an external high pass (corner frequency at say 27Mhz) fi

I have a 2000ohm headset which I have used in a 4 ohm speaker output of a drake receiver. Using a matching audio transformer indeed the volume increased significantly. In fact I could hear some hum wh

#ubitx

My front and back panels are plastic, all the rest is metal. So all connectors are isolated. I used a small piece of coax for the RF connection from the board to the panel instead of the stock twisted

#ubitx

I guess an audio active filter 200hz wide like the Hipermite by 4SQRP might suffice.

#ubitxcw

I had keying errors when the jack contacts were not clean enough or were not doing a perfect physical contact. Replacing them and keeping clean with isopropyl alcohol solved that issue.

As it was QRP stuff I didn't find inappropriate. If it had been the selling of ordinary flashing brand stuff I would have simply considered it as spam.

That's interesting! Am looking forward to becoming an addicted Antuino user :)

I understand it is meant mainly for HF, but what is its usable frequency range? Is it usable at 6m, 2m and 70cm?

Great news! Would the final production of Antuino embed all the hardware and firmware improvements, tested and calibrated at the factory before shipping?

In the EU as you know we are limited up 7200. Maybe it would be just convenient to use standard qrp frequencies (CW/SSB) to meet other qrpers.

#bitx40

I remember 160m just needed a lowpass filter. I am not sure, maybe it depends on the versions, whether changing (increasing) the values of emitter caps such as C81 might be useful for lower bands. I a

I am happy Yaesu would sell a ton of 2m radio. Maybe to Thales. Look, consumers will take into account the fact that they might eventually loose the 2m band in 2023. There is a risk, there will be a p

Excellent! Inexpensive and fast repair! Thanks for this informative feedback!