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Member of GQRP, n. 10529 & SKCC, n. 12762

QRP and CW enthusiast. Builder and user of simple equipment for low power communications on HF, mainly with valves, sometimes with discrete solid state components. Frequently QSX on 3.560 kHz in winter, 7.030 and 14.060 kHz during spring/summer/fall, on QRP. I don't QSL via Buro but I appreciate a lot receiving/sending QSLs directly.

My activity is 'minimalist' in the sense I don't use commercial gear: old receivers with adequate performances and homemade transmitters and receivers are preferred.

I love the Radiotelegrapy: it allows the Radio Operator to get everywhere with simple equipment. It is the Operator that, most of the times, makes the difference. Not the radio set. Radiotelegraphy allows me to keep everything at the simplest level, and for this reason, it allows the greatest satisfaction.

Radiotelegraphy is undeniably a style of living and has a sound technical value in itself, despite the Official Services discarded it since 1998. By it, a Radio Amateur can get the maximum performance and satisfaction with minimal means. It takes a bit to learn it, but the effort is rewarding.

I consider as true Radiotelegraphy masters those former Radio Officers of the Merchant Navy. Sometimes we, Radio Amateurs, exchange velocity for quality. It is not like that. True Radiotelegraphy Operators can copy any sequence of letters and numbers, without missing or mistaking anything. I spent many hours listening to the marine radio traffic on HF and I consider that kind of traffic as my preferred operating style. The shut off of the traditional HF maritime radio stations, in favour of the satellite based communication networks, has been a very sad event. Once more, the technology has swept away a world of professional competence in favour of supposed better systems, that are still quite questionable regarding efficiency and reliability when it comes to the safety of the Maritime world.

So, I like Radiotelegraphy and I like practicing it just for the satisfaction of improving my operating skills by ordinary QSOs. Every QSO on CW reminds undeniably a famous William's of Occum (1290-1350) statement:

"It is a shame to do with more, when less will do"

More technology not necessarily means a better world.

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The main transmitter: a home made MOPA (Master Oscillator - Power Amplifier) built on 2003, by which I made thousands of QSOs. On May 2015, after many years of experiments, I successfully had it covering from 1.6 to 29.0 MHz, on AM/CW, semi break-in and full break-in. The principal feature is that it uses only a single frequency multiplier, which, on the higher HF, triples the VFO frequency. 

 

The 'centre of gravity' of my station: the VFO! Homemade. Alongwith its power supply at the left. This is a REAL PIECE OF JUNK, about 10 kg of machined Aluminum, built around a marvellous BC221 variable capacitor. With 6 bands, goes from 1.6 up to 9.5 MHz. It is very stable and the resulting CW tone is just perfect.

 

The antennas: a 70 mt 'butterfly' dipole, with balanced feeder, up on a 20 mt tower. 140 mt of wire up over the ground. And a self-sustaining 20 mt long dipole, made with fishing poles and fed through a balanced feeder too. No rotor, neither high gain directional antenna. Those are more than sufficient to reach any part of the world on QRP. 

 

My son 'JACK' (year 2013), playing with the radios at the operating position of that time. He seems to be rather promising, eh? Time will tell it.

 

In the background of the above picture, a few 'sins' of the past: two Rhode Schwarz EK56/4 receivers, not own anymore, and a double conversion valve transmitter, covering from 2 to 22 MHz, AM/CW, 200 W out. The EK56 were solid state: really excellent radios, but too complicated to fix and becoming critical regarding spare parts. Better to part with ...

The big black transmitter looks as this:

 

... its PWR Supply/VFO/1st Mixer/Modulator module interior .. 

 

.. and the 2nd Mixer/Drive/PA module interior:

 

I designed everything and made almost everything, apart from the black 'wrinkle' box. I needed to touch at least once the edge of extreme complexity to come back to a reasonably sized reality. It took one year and a half to put all this stuff together. And I will never ever do that anymore. Stay assured.

 

On August 2016 I was ready to make a huge step back to make a huge step forward: I built a Hull-Hartley CW-only transmitter, using a single triode, a RK34 - VT224 (dated 1944), by replicating the same schematic from the early Radio Amateur stations in the 20's. Fed by an electronically stabilized plate voltage supply, using a series regulating pentode, it puts out from 5 to 7 W on a wide range (1.7 up to 5.5 Mhz).

Recently (Oct. 2016) the main coil has been replaced by a similar one, salvaged from a demolished BC-191, but having thicker conductor: up to 15 W or more can be loaded with only a tiny worsening of the tone quality, but with a much greater frequency coverage (3.2 up to more than 12.0 MHz !). By properly setting the number of turns in the resonating tank, the feedback tap and the number of turns on the antenna link, almost the same tone quality has been achieved on 7 MHz and improvements are also possible to reproduce it even on 10 & 14 MHz. The secret for such results are both mechanical and voltages stability.

A 'step back' because the schematic/technology is from the 20's. A 'step forward' because by using only 10 components a CW tone quality is achieved such I couldn't believe ... This TX feeds one of the two available dipoles, and one of my receivers is fed by the other one. Full break-in.

The strange effect of this 'wireless set' is that ... I'm loosing interest in doing traffic with my 'sophisticated' MOPA and my old, but still good, big receivers ... I have experimentally coupled the Hull-Hartley TX to a regenerodyne ('super-gainer') receiver, and more than plenty of performances were noticed to make day-by-day traffic on the lower bands.

Perhaps the day in which most of my radios will leave the shack is not that far. My Hull-Hartley reproduction, with sligthly more recent components, allowed me to be minimalist but not suffering from unacceptable limitations. The frequency it generates is pretty stable (wind permitting ...) and chirpless, so that often is not easy to distinguish this transmitter from modern stuff, when on the air.

 

On June 2017 the main trasmitter, the MOPA, has been sent to retirement and put on the shelf, and I've decided to go on air with the following setup only:

 

These are now the only two radios at the operating position. At the extreme right, the stabilized anode voltage power supply, made by a series-regulating pentode (6BG6) driven by a high amplification tube (EF184). On 7 MHz the Transmitter is still somewhat critical, being quite sensitive to the antenna wires swinging in the wind, and for this reason the tone results sometimes a bit unstable. Though, generally, the quality is acceptable and I've collected about 150 QSOs in total so far.

A still not ideal behavior of the transmitter on 7 MHz is a continuous stimulus to refine and improve it. On 3.5 Mhz, on the other side, the performance is actually excellent: almost digital.

The toroids at the right match the unbalanced output of the transmitter and the unbalanced input of the receiver (EK07, this one not minimalist at all, but ...), with the balanced lines of the dipoles.

The above set up will be kept up the end of 2017: let's see what I can do with this ...

And here the 'regenerodyne, that's a semi-serious homemade receiver, built with valves only too. A personal interpretation of the 'super gainer', to which a RF preamplifier has been added ahead of the mixer. The detector after the mixer is a regenerative stage. The 'tuning eye' is wired to show the audio level for simplicity, but helps somewhat to make a fine tuning at the antenna preselector.

 

73, Cris

8241359 Last modified: 2017-07-28 09:30:35, 14847 bytes

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