Paul, Using the T-1, it will step through a lot of settings including those creating a high SWR, which can damage the QDX running at full power. To address this issue, it is wise to reduce the output

George, Thanks for the article on Moon Phase and propagation I have not seen it before. There is also an enhancement at the onset of a geomagnetic storm. Before the Kyoto Dst value drops, indicating a

Hello George, 60 years ago, I was active as SWL chasing DX on 80m. At full moon, propagation was always better. The last 20 years I have been chasing NDB's on long wave and believe it or not, the same

Hello Wolfgang, It was not clear that your example featured a 3/8 wavelength ground plane. This makes it even more interesting. Instead of the T-match tuner, a simple L-network at the base of the ante

Hello Wolfgang, With due respect your example is a bit over the top. Nobody with some basic antenna knowledge will feed a long wire with coax. For reception only, yes, as on HF the additional loss of

Hello Wolfgang, These calculations are not correct as the source impedance (your transmitter antenna port) is not 50 ohm. It must be connected to a 50 ohm load, yet is not 50 ohm itself. If this shoul

Eric, - using my TC-1 Multifunction Tester. It tested good although the HFE was higher than I expected. It was 390 I found the same here. Transistors which tested an HFE of 200 on a cheap DVM, measure

Hello Alan, Some time ago I have measured the sensitivity of my QCX+ for 40 m with old school test gear: Signal generator Marconi TF-2019 20 dB Mini-Circuits attenuator HP-3400A RMS voltmeter First I

#qdx

Hello Mario, Yes, changing to words is a nice step. You are most fortunate that the majority of on-line training material is in English. I am not a native English speaker and so far I have not found r

Mark, The original WB4VVF accu-keyer as published in QST in 1973 does not support the Ultimatic mode, it is a iambic keyer, which comes in two tastes: A and B. 73, Roelof, pa0rdt

Hello Mario, Human brains are different per individual. Some people have a preference for visual input, others are better served with aural input. The latter applies to musicians and this is a bonus w

Dan, Sure, here it is: https://archive.org/details/hamradiomag/ham_radio_magazine/Ham%20Radio%20Magazine%201969/12%20 December%201969/page/n3/mode/2up 73, Roelof, pa0rdt

Jack, Thanks for the information. It is amazing that Morse code still inspires us to try new things. This is still the same as 50 years ago, when I read several articles in Ham Radio Magazine about an

Hello Hans, Thanks for the insight information, which confirms my observations. As decoders go yours is very good indeed. In fact the QCX-decoder is almost too good for monitoring my hand keyed Morse.

Jack, I believe the CW decoder in the QCX is based on the DSP Goertzel decoder: http://skovholm.com/cwdecoder It works very well. I use it to monitor and improve my straight key sending and it is quit

I had a similar issue and it appeared to be a leaky C22, a 1 uF capacitor. If this does not help, you might look at C21, also a 1 uF capacitor. These have been reported to be prone to leakage. 73, Roe

#20m #problem #qsx

Hello Ed, - I rarely operate at higher power anymore because it just seems too easy. Is that not the whole point of using QRP in any mode? 73, Roelof, pa0rdt

Hi, Good question and one I have asked myself. My antenna is a 2 x 16 meter doublet fed with 11 meter open feeder which enters the house in a fixed cupboard in the living room. Don't ask why! The shac

#antenna #tune

Hello Wolfgang, Something is not right. Have you tried a different power supply and current meter? Yours, albeit a lab version, might be sensitive to rf-ingress, which might cause all kind of problems

#qdx

Hello Chris, I found that the lowest range of the BM4070 is 200 uH. This means that measurements in the 1 uH range can't be very accurate. The datasheet gives for the 200 uH range an accuracy of 3% +/