giovedì 20 novembre 2014

Ham Radio, my life!






A friend of mine, Cris IZ3CQI, some days ago wrote this sentence, speaking about Ham radio peoples:

"People that deeply enjoy surfing the shortwaves, that cannot live without hearing 
each day the typical shortwave noise from a loudspeaker..."
and  it fully a truely describes my Radio mood .

It's something without any explaination, but it is a deep feeling. Really true.
Thanks to my friends so able to put in words our feeling!

mercoledì 12 novembre 2014

Rocky Tube QRP tx

Got from several circuit and then modified as I did not have components needed.
This is a first attempt to make a simple XTAL rocky TX with low power. Using some xtals on 40 m, and thinking to modify the frequency pulling of the xtals in future as suggests F6HCC in his nice webpage.
The original circuit was taken by an ECL82 single valve QRP TX from  G0UPL & c., but by the way I broke the valve (first time in 40 Ham carrer...:-( ) and so I had to modify as I have not yet any ECL82 for spare (Murphy law alway valid!).
A really good suggestion and link came from my friend Enrico IW3FZQ

So the choice has been for a 6N7 double triode as I have three of this: first is a XTAL Pierce oscillator and the second triode stage is a driver and the PA is made by a 6L6 old fashion tube (what I used on my Geloso VFO G4 102 in 1974 at the beginning).
The schematic are quite all the same and seems a really simpleto put together the component and in a couple of hours to be on the air.
    
Not for me!
     
First of all I don't have a lot of components in my actual lab, as when I moved from old house in Rome I left a lot of them in the boxes in a wharehouse and they are there yet. So I had to carefully choose also resistors I had from an old Oscilloscope I dismounted and also the tube socket was a spare without one pin and so on...
Then all was assembled and oscillator and driver were ok but no so strong signal. I mounted the 6L6 amplifier and so discovered that power was just less than one Watt!

Checked all voltages and circuit no reason to have so QRPpp signal, but after dinner I had an idea to make the signal growing with a resonant LC tank. In fact I remembered a simple "75watter" article on some handbook and between the 12BY7 oscillator and PA was inserted a simple parallel LC circuit.
I made it and connected and magically the power raised a little bit less 5 W!




 The Bird says about 5 W!

 

The complete TX now :-)....  no cosmetic 
(in the middle the new tuning capacitor for the driver stage)

 
So now the TX is functioning althoug is really just a prototype, but it's ok and it's mine and is nice to view in the dark evening with the two tubes lightning and the hot from them and from the dummy load (just a couple of paralleled 100 Ohm 2 W resistor).

PI-Tank


Power supply




Tomorrow I'll do the key circuit on the cathodes and I'll make a try for at least one QSO, but this evening I'll go happy to bed for this my first valve TX in the new Ham era for I5SKK.....hi

The new LC tuning for drive


2nd harmonic at 14 MHz is 32 dB down


Yes, the home construction is really a doping for Hams...hi


"New" next VFO

It's ok!
This morning I received the BC221, without the power supply,  I got from an OM in North Italy and I have here on my shack.


I had in my beginning another BC221 I used it as a frequency meter and then I missed any record about it, I sincerely don't remember anything and it's a pity!
It was a nice VFO I rememeber, but a those times I did not appreciate it in the same manner as I do today and so here I am with another BC221, AH model, in order to use it as a future Master VFO for my tubes station..
I donwloaded the manual and the schematic of course, and I just planned as I'll use it in a big, but not too much box with his so nice tuning knob at the centre and when I'll use ti to tune and spot I'll enjoy more than if a frequency meter that we don't use so much in any staion.

The tubes have a fashion to me now: the lights and the heat I receive from them, and when I look at  the window and I see the clouds behind my house valley, I enjoy to be at home, with hot from tubes and by signals coming from every places in that sound that's the CW peak.

Nice Passion the Radio, so true!


Viaggiare "sulle" Onde....



Non a caso le hanno chiamate “onde”, tanto tempo fa: waves in lingua Inglese, e rendono l'idea.”onde” perché fanno parte di un fenomeno ondulatorio, di sicuro, ma anche perché le onde, del mare, e del vento (se mi si consente questo “traslato”), viaggiano, vagano, senza fine, senza limite e senza possibilità di essere incanalate. Tant'è che l'acqua ogni volta che vien incanalata, prima o poi, come si dice oggi, “esonda”, insomma esce fuori, non ci sta, dove l'uomo vuole ingabbiarla.

E così la nostra anima, il nostro spirito!

Ma cosa c'entra con la Radio? C'entra e me ne sono reso conto ieri sera.
Alla cabina ENEL di fronte casa, era saltato, con gran dovizia di fumo, un trasformatore che serve evidentemente a dare corrente a tutta la zona: luce alle abitazioni e alle strade.
Eravamo al buio, in casa e fuori. Un nero incredibile, raramente vissuto, specie in casa.
Avevo sì la mia luce a LED, ma la sua autonomia è limitata da una batteria, e volevo tenerla, non si sa mai quanto durano questi guasti.
Stavo lavorando al laboratorio: un TX a valvole, roba d'altri tempi; senza corrente alla spina sia il saldatore che l'oscilloscopio erano morti. E così anche il ricevitore fisso su frequenze attorno a 7.025-7.030 kHz.
Poi mi è venuto in mente che ho una batteria da 7 Ah e che uso nell'attività portatile in montagna e quindi l'ho attaccata e mi sono messo alla radio, non distrattamente come quando lavoro, ma con l'intenzione di collegare qualcuno.
1W output la mia potenza che uso in questo periodo, poi se serve uso anche l'hig... ben 5 W, ma voglio provare, giocare, con 1 W in generale.

Su 7.030 kHz c'è un CQ: F6FTB che chiama QRP.
Rispondo, completamente al buio, unica luce quella del display blu dell'apparato.
Chris, così si chiama, usa 4 W, TX homemade, ed un'antenna dipolo, io 1 W ed una windom, caduta in terra da 10 gg sotto l'impeto del vento lunigianese, un bel DX!
Eppure io passo 589, un segnale ben stabile e forte, e ricevo 549/559. Andiamo avanti per 20 minuti! Ci si descrive la stazione, le condizioni del tempo, cosa facciamo col saldatore, insomma chiacchieriamo ed i segnali restano stabili: alla faccia di chi dice che in QRP, e specie in QRPp non si possa far altro che QSO rapidi!

Attorno a me il buio resta unico padrone. Nessuno esce di casa dei mie compaesani, nessuno in strada tranne gli operai dell'ENEL al lavoro, io in casa, eppure con l'animo che corre sulle ali delle onde, delle onde della mia Radio, fino in Francia, a Digione.
Un QSO che vale mille DX, una chiacchierata che vale una chat su FB.
Un piacere durato e non flebile, che si esaurisce dietro un sms, o dietro un banale gesto in strada.
Un Essere Umano che ha incrociato la sua strada con la mia.

E quando chiudo, ripenso a tanti altri QSO del genere, fatti con poca potenza, ai miei albori, anni '70/'80, forse 10 W, collegamenti anche esotici, ricordo la prima volta che cercai dov'era “Tuvalu” o quando andavo di corsa a misurare la distanza con la stazione che collegavo, ed ero uno studente, prima di liceo, e poi di università, ma di sicuro senza i soldi necessari per andarci in quei posti lontani.
Eppure mi sentivo e mi sono sentito libero, felice, libero come il Gabbiano Jonathan, felice come forse mai più è stato.

E le stesse sensazioni non le provai quando un amico mi prestò un lineare, Viking modificato, che dava fino a 800/1000 W. Non era la stessa cosa, era come se...fosse troppo facile, non c'era gusto... era come oggi viaggiare vedendo la TV. E difatti durò due o tre mesi, poi tornai alla 807 ed ai suoi quasi 25 W o al VFO Geloso con i suoi forse 3 o 4 W!

Viaggiai e volai, per tanto tempo ed oggi ancora lo ricordo bene e lo rivivo quando appunto, come ieri, ho la fortuna di poter fare certi QSO. Non serve arrivare oltreoceano, basta andare anche da un DJ o da un OK, ma la potenza piccola rende tutto questo, magico, diverso, affascinante, e unico!

Questo è il QRP o anche il QRPp per me, il resto, il DXCC, i contest, o tutte le altre forme di competizione, non mi provocano queste emozioni, passano, vanno via e rimane un ricordo, alle volte, altre nemmeno quello.
Queste emozioni rimangono, stampate col fuoco nell'animo, nella memoria e nel cuore.

Per me, la Radio, la potenza ridotta è questo: viaggiare con le “onde”, o meglio sulle “Onde”



domenica 9 novembre 2014

Back to tubes after a long time

A long time was spent in my Ham life and after beginning when tubes were the only way to be on the air, slowly I left for solid state equipment, as obviously.

My beginning was using a Geloso G4-102 free running VFO and 6L6 tube as a PA, really QRP (2 W I think), and later adding an 807 PA, really a QRO for me.... hi

In the times I left tubes as when I was young and then an electronic engineer the state of the art was about solid state, as it was (and still  it is so) compact, portable and less dangeorus obviously.

But fashion and feeling that you have looking at the red light inside the tube, and the blue light you see in the PA when key is down is something not equal to anything in tech, and so after 40 years, now that I'm living in a countryside I've a little bit time to spend in doing my tubes equipment once again.

So last afternoon I put together the power supply and the the ONE TUBE TX with an EC82 I had in the junk.





The transformer is from a IK0BDO gift and the components are from and old FL101 I dismounted some time ago as it was out of function.

Then it was the time of the tube itself and so the ECL82 found a place on an old pcb I made for a project by IW0BZD, Pino, in the LF reception.
After a while the circuit wa running and a clean note was on the FT817 I use as a monitor and on the spectrum analyzer screen.





But it was just the oscillator part of the double tube, as ECL82 has a triode and a pentode part. SO the amplifier was done accordin various project I found on the web. The main was from Hans Summesr G0UPL.

So at the end I was able to put together the whole TX: oscillator, and PA and PI-Tank using the old FL101 tank and a couple of capacitor I had .
The result is very rugged and so I have to put in a cosmetic form and to do it better, but anyway the first tube TX after a long time was made I this is what I like. Mybe in the winter I'll be able to be in the QRP MAS contest I like so much. Who know...?