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I hope that's not too long. You could test the RX on Dial 5.364700 (TX 5.366200+/-) as used in EU. Conditions not been too good X-pond the last few days but usually signals make it OK. 73 Alan

Hi all Just a quick observation. It is indeed VERY difficult to replace components, or to take turns off toroids and get the wire back into the hole when it is filled with solder. Here I do have

Just an update on my 60 metre QCX.? So, I did have to remove 5 turns from T1 to be able to peak the C1 trimmer. Luckily, I have a solder sucker, because trying to poke a 30 AWG wire through a

Chris, Possible but not really necessary. A LPF does not peak, it is not really too critical. I'm not sure I've ever seen an adjustable LPF. I guess if the inductors are too high then the amount of

Hello Peter, I have never built one of these, but is it feasible to build an external LPF with beehive trimmers instead of the fixed caps to bring one spot on? Wednesday, November 8, 2017 -- Best

Has anyone built their QCX's output filter first on a bit of board to "tune up" the turns on the L1,L2,L3 ? PeterO G0DZB

Julian, I think L4 is the key? I think Hans has said it's resonance is what makes the PA (almost) work in class E. And that is is one reason why the QCX is mono-band. 73 Alan G4ZFQ

See also http://qrp-labs.com/faq.html#cal 73 Hans G0UPL http://qrp-labs.com

Ted, As Chris says + Are you sure frequency is right? (And timing) I cannot remember the setting but the GPS compensation default takes a loooong time. No RX in shack? 73 Alan G4ZFQ

I ordered one fom CPC yesterday morning, and it arrived this morning (via UPS) just in time for me to start building my 30m QCX PeterO G0DZB

Hello Ted, God knows, I am no expert, but assuming you do not have an oscilloscope I would start by putting your multimeter on a suitable current scale in series with the PA power

Finally got my U3S attached to a known-good antenna. I configured it for WSPR (on 40m) and let it transmit for a couple hours. No data seen on wsprnet. I know it works; I've been running a wsprlite on

Here is a table of the RMS output voltage/power I'm getting. I've tried tacking 20pf and 50pf capacitors across C30, but that lowers the output at 7.030mhz Julian G4ETS

Hi Joel, Your are same with my result. I have took out 1 turn form L1, L2 and L3. and my output power increase to ~2W @13.8v I plan to experiment with replace MPS751 to Q6 this weekend and see how

To builders who want this device and are not in England I searched the internet and most were over A$25 However HobbyKing? has them for A$8.09 +

Here is the FFT image. I've also put an image with no signal, to give an idea of the noise floor. The signal looks pretty clean to me. It's just that I'm not getting the power peak where I want it,

Hi VK5EEE Are your L1, 2, 3 & 4 now as the table (assuming 20M) i.e. L1 & 3 = 0.77uH, L2 = 0.9uH? L4 = 0.4uH What is your power O/P and transmit current? 73 Mike G0CVZ

I ordered the 20 meter version QCZ on 8 August 2017, order #748,? and it arrived today, 7 November 2017 in Detroit, Michigan!? It was in its own box and not in any other packaging, but was received

If you can measure the inductance on each toroid individually, as in my case I had to remove 1 turn from 1, 2 from another and 3 from another, among L1-L3 if I remember correctly. Otherwise if you

One problem with using the QCX TX to measure the LPF is that the resonant L4+C30 will also be a part of the equation. Best would be to insert a known signal (SNA/VNA) at C29 (removed) and see how the