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My motto is "Always use just a reasonable power". So whenever the conditions are good and I hear the other stations well I often try to call first with the minimum power, usually under 5W.
When I started on 160m back in 1971 the legal limit was 10W input and I did not exceed it, so I was QRP right from the begining.
Later in 1977-78 I got inspired by the G-QRP Club, G4BUE and QRP ARCI articles in the ham magazines and I became very active on real QRP and QRPP (under 1W). I operated in most QRP activities, contests and normal random QSOs around the QRP frequencies, I also did a lot of constructing and antenna experiments, all in the true sense of amateur radio. There were fun projects such as simple portable VXO transceivers, transceivers with 20 components, or more complex projects such as CW/SSB VHF transceiver or transceive adapters for HF bands (see "Equipment").
I took the challenge and started DXing with QRP and achieved DXCC on 3 bands, the DXCC QRPp Trophy Nr.20 in June 1980 and the DXCC Milliwatt Trophy Nr.10 (under one watt) in May 1986.

I made a lot of interesting milliwatt and microwatt experiments which proved that under optimal conditions on HF bands contacts can be made with just hundreds of microwatts.
These experiments resulted in several of QRP ARCI "1000-MILE-PER-WATT" certificates. (The concept of these awards is to achieve over 1000 miles per watt which is calculated as the distance divided by the power, hence one can reach 1000 miles per watt working 2000 miles with 2W as well as 100 miles with 100mW.) One of these certifies my record QSO in 1980 on 15m band with G4FKL with a power of 600 microwatts, hence 1241667 (yes, over 1.2 million) miles per watt. This was later exceeded by more microwatt QSOs on 15 and 20m bands.

In 1987, having built a CW/SSB 144 MHz solid state transceiver I started some milliwatting on VHF as well. This TCVR's output power was 50mW and I built in a separate 2 stage 3W amplifier.

By means of controlling the gate voltage of the dual MOSFET driving stage the output power could be varied in a wide power range. I did some precise calibrating using a laboratory HP digital power meter and made a calibration table that I fixed on the top of the transceiver that helped me to adjust any power output of the "barefoot" TCVR from the maximum of 50mW down to 115uW (microwatts), or with the internal PA from 3Watts down to 2.5mW. This allowed me to play with very low QRPPP levels on 144 MHz CW and SSB.

Hundreds of microwatts did not seem low enough though, because I could achieve QSOs over the distance up to 50km. I found that I could go down to nanowatt level by simply disconnecting power from the two stage PA which then only served as an attenuator and I could set output power from 35 microwatts (0.000035W) down to 160 nanowatts (0.00000016W)! I could talk to my friend OK1DZD on SSB over the distance of some 50km at the 35uW level, 20km at 2.5uW, over 8km at 770nW and finally the record QSO over 22km at 160nanowatts!
(More details about these QRPPP experiments will follow - QRX).
On the other hand these experiments show the importance of a very clean signal on VHF. One can easily radiate spurii at microwatts or nanowatts from a QRO station with unclean signal.

I am a founder member of the OK QRP Club
Nr. 001

Member of G-QRP Club
Nr. 426

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