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I was trying to tune the R5 trimmer using 20 vdc. I did start with the pot turned all the way counter clockwise. Turning it slowly as per the directions the current draw never changed, at around 6.08

Guess I need to look at mine again. IIRC, the power reading was ok, but the VSWR was off by more than I expected. Mike WM4B

Many thanks, Bill and others.? Yes, my scope is 200MHz, so should be fine. ? Karl

Here is an explanation of using the uncovered scope probe I just mentioned to make measurements impacted by ground loops in noisy environments.? It is difficult to make a more sensitive measurement

One of the things I love about WSPR is learning about the listening community. Alf, LA1ZM, is also part of the QRP Lab community with his U3s. I like to look up, many of the spots on QRZ, and what an

Here is what I did - at first I inadvertently measured at the left ground end of the power resistor inside the Dummy Load.? Then I measured it at the correct location.? However, to be more exact,

Hi Karl, The answer to your question is that it depends on the power being applied and the voltage rating of the scope.? At 10 watts with a good 50ohm dummy load, you could see 63 volts or so peak to

Hi Karl, Your scope probe goes across the load resistor. Select the appropriate voltage range for the expected RF voltage to display on the screen. I don't know what resistor the other guy was talking

I had a bad IC10 when I had the same symptoms. From new. That was with the original mini version. I removed the capacitors around it and was able to remove and replace it.

Hi, I don’t have a QCX, so I’m not sure of the resistor you speak of.? My question is, though, if I attach a dummy load to my 5W TCVR, is it OK to just put a scope in parallel with the dummy

My QCX+ driving an MFJ 1.5KW Dummy Load and measured with a scope probe inside the box right at the top of internal power resistor yields 9.5W.? The DL was attached with a 3' length of coax. The

While its well designed for HF pushing to VHF is going to be far from optimal. I do 160 to 1296, core radios for that are FT817, Tentec 6n2 plus three monobands for 10 (if radio), 6, and 2 all purpose

Michael, if one searches on-line for "batch 2" (with quotes) there are a lot of relevant hits, including /g/QRPLabs/message/74070 </g/QRPLabs/message/74070>. And in

Hi Hans, Regarding QDX batch 2 I would be curious to know what changes you have implemented in the new PCB revison. I guess the circuit has not changed, or has it? Thank you for letting us know. 73 de

Hans, If there is proof of the WSPR "anomaly" detection then it must already be in the WSPR database. It just needs someone to do the analysis and prove it is. Someone who can show he is not selecting

Hi Trevor, Alan I read all the links in the WSPRnet thread. I read the documents you linked to. I would like to believe. I wish to believe. But I cannot... Some of the documents seemed to start off in

I am like you, I can't see how this could be possible for all the reasons you give, nevertheless incredulity is not a sound basis to refute evidence given by somebody. Assuming that the blind tests

Trevor, Thanks, It does look as if the method has some chance of working although this seems to relate to aircraft close to one end of a path. I started by doubting the possibility, then wondered if

That sounds like a lot. Can you confirm if that is into an antenna or the dummy load? What does the SWR read as? Run thru both meters in series, do they both agree? Do you have another dummy load?

The QRP Guys power meter was one of the most fun quick kits I ever built. It's pretty stinking accurate too compared to real test equipment. I tested it. So it must be. It's nice field test gear