I've used mine for WSPR as well but am not comfortable running the full 5W output for two minutes. Turning the supply voltage down to 9.2V on 40m produces 2 watts out and the QDX runs cooler.

#20m #antenna

I added a 20 dB, 5 W attenuator in series with the antenna line and have been running 17 dBm = 50 mW on 20m and 40m WSPR. Quite amazing how well the receiver works, even with the attenuation and also

#20m #antenna

Ted My God given fingers are my best troubleshooting tool also, well only when the voltage is much lower than 100 volts. Yes technical folk don't like the term counterpoise, but you produced a good on

#40m #antenna

Thanks again all Hilariously whilst fighting off a horsefly I accidently pressed the key and also touched one of the bnc outers. The side tone returned and stays there as long as I hold it. I might ha

#40m #antenna

In my journey as a new amateur radio enthusiast, I find one thing that stands out. A proper understanding, selection, design and implementation of your antenna system is critical if you want to maximi

#40m #antenna

Steve Ellington, N4LQ (Steve Ellington on Youtube) has done quite a bit of EFHW kit building, has a few presentations on the EFHW, and discusses at length the pros and cons of the antenna and differen

#40m #antenna

Very good, thanks!

#40m #antenna

that is easy to check.. For the bridge use a FT37-43 ferrite toroid. The tuned circuit use a larger T50-2 or -6 for QRP ot for higher power I used a T157-6 I had. For high power you need airspaced cap

#40m #antenna

Do you have information on the toroid specification? Thanks.

#40m #antenna

Huge thanks everyone for the responses, much to ponder. I should have posted this earlier to avoid confusion, this is the circuit that the matching unit is based on. 73s Ted

#40m #antenna

I suppose Ted's tuner is not the 49:1 wideband type, but a "Fuchs tuner" (parallel tuned circuit), since it clearly has a tuning knob ... I have the same setup, and yes I experience the sidetone getti

#40m #antenna

FYI: that tuner does work if you use the correct tuning procedure. Firs tune using a resistor I use 2700 ohms for low antenna and 3300 for higher. Then attached the monoband wire and adjust its length

#40m #antenna

Ok A properly tuned (wire length is correct) with match box should not be a RF in the shack issue. Generally is a common thing to blame the cow for soggy cereal when that is expected when you pour on

#40m #antenna

Ok A properly tuned (wire length is correct) with match box should not be a RF in the shack issue. Generally is a common thing to blame the cow for soggy cereal when that is expected when you pour on

#40m #antenna

Hi Ted like others have said the Have wave is a high voltage feed point and the little matching unit you have made will have a 49:1 transformer in there as the impedance on a halfwave will be 1000's o

#40m #antenna

Hi Ted, I have a 20 meter QCX classic and also use an EFHW antenna (~33' length). To match the antenna, I use a Pacific Antenna SOTA tuner that uses has the same circuit design as the QRPGuys tuner. I

#40m #antenna

Forgot to add, nice job on the matcher construction too.

#40m #antenna

Hi Ted, Half wave end fed = voltage feed = max rf voltage at the feedpoint. That can lead to various problems, typically the "rf in the shack" syndrome and can sometimes play havoc with any rig. Bette

#40m #antenna

I've recently built a HWEF matching unit from a circuit diagram I found on the Web which I have subsequently found to be identical to the qrpguys kit and a few others. (I've decided it's time to go ex

#40m #antenna

For the final try without the tuner, I got 1.16:1 @ 7.055MHz, 1.25:1 @7MHz, and 2.01:1 at 7.3Mhz.

#qcx40 #40m #antenna