Hi Steve, I did once suggest on this forum that all inputs and outputs to the QCX mini should be idiot proof, but I was burnt at the stake for such heresy. So in secret I will tell you I cut the 5v li

2 I adjust power via the WSPR menu in the radio. I can hear it when its in TX mode on another rig. As Julian pointed out,this shows you misunderstand how WSPR works. There is NO variable RF power cont

Hi Steve, no the pin out is not the same. There are some excellent guides on the forum how to do the mod. It seems much more tolerant to abuse as I have done it myself. regards Ken G4APB

Hi Joseph, I presume the connector you were talking about is the one controlling the raised cosine control. You could try a temporary bypass to get the 5w pa transmitting to see if your display is imp

Hi Steve, the tip on the qcx-mini is the 5v supply and the ring is ground. Here is a fatal flaw….as you suspected plugging the jack into the 50w amp while the qcx is powered means a short to ground of

Hi Joseph, you asked this question before, did you try my suggestions below?… Stray rf into the display can cause this, especially if you are feeding the 5w back through the U3S onboard lpf. Are you r

Hi Gary, i’m the one that asks the stupid questions so you can ignore the next if you want… 1) Each is setup using the exact same process… can’t be right, cos they run at different frequencies right?

Hi Daniel, I am always looking for the blindingly obvious but here are some stupid questions… How do you know the qcx mini is even going into transmit mode? I see you have a paddle connected, have you

Hi Alan, The link suggests a resistor should/was adjusted for 50mv on the sources of the driver stage bs170s. I only measure 36mV on mine, that is almost 30% low. Do you think I should change the 33oh

#10W_PA

Thanks Alan, no I did not read it all the way through because it was about matching devices (which can’t do much about now as devices are installed) , and only now do I realise the bias circuit was an

#10W_PA

After all WSPR = Weak Signal Propagation Report.….. all this worry about too much rf out….. so why was wspr specifically designed to cater for up to 1kW coding instead of more levels of sub-mW powers?

Having previously started a similar thread that seems to have close connections...I repeat.. QUESTION 3: Why the first stage amplifier (two BS170s) has a complex biasing circuit while the second stage

#10W_PA

Hi Larry you will need an inverter transistor to convert the 5v high on u3s tx to the low needed to key enable the 10w amp. Small series r to the base of the transistor ( a few kohms). You will also n

Hi Julian, I have done earlier postings on this but just to repeat for you, I ran a wire to permanently monitor rf power with the intention to check rf power out using the battery monitor icon as it i

hmmm, time for some amateur self learning maybe? ….but your suggestion on checking the serial connection is over my History Major head. I presume you have access to a computer? If you have one with th

#clock #gps

Hi Paul, if you set the clock time manually, does it keep good time ? If it is not, that can point to the processor not running at the correct speed, and that could stop it reading the data. I once ha

#clock #gps

Hi GIUSEPPE, There could be several problems here. Stray rf into the display can cause this, especially if you are feeding the 5w back through the U3S onboard lpf. Are you running the U3S at 12v too?

Hi Paul, if swapping the 1pps and data lines produced the ‘incorrect’ 1pps indication, it does show that the DATA line pulsing is reaching at least the 4 connector input input on the clock, so.. you c

#clock #gps

Paul, try swapping the DATA and 1PPS connections. I found that the heartbeat will flash if the DATA line is incorrectly connected to the 1PPS input, giving you a false indication and no data displayed

#clock #gps

Hi Makkaito, thank you for the very informative video. I noted some very interesting points; 1) In one video you show a quite distorted waveform, like a bent over sine wave and also a very distorted t