My First-Ever QSO -- 50 Years After Passing Ham Test

Discussion in 'Ham Radio Discussions' started by G3EDM, Aug 27, 2021.

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  1. G3EDM

    G3EDM Ham Member QRZ Page

    So it finally happened, with the usual Novice screw-up, namely, that although we did converse usefully, I must have mangled my caller's callsign because I cannot find it in QRZ. He answered my CQ but the QSO ended abruptly after a couple of exchanges. QSB was a major issue (see below).

    What I have is DF6YFD (which apparently does not exist). I thought that suffix was correct because he repeated the suffix (and only the suffix) several times, but in retrospect, it may be that I kept mangling the suffix (hence his several repetitions of it!) and maybe I never did get it right.

    His name is Bernhardt. His QTH is near Bremerhaven. He did me the great courtesy of slowing down his Morse to a crawl, and repeating the long words, such as the QTH. The frequency was 7030 (not 7035 as I initially posted here), the time was very roughly 0620G (I was too excited to check!) and he gave me an RST of 599.

    At my end, on my little three-transistor regenerative RX, I could hear him 569 but with heavy QSB.

    I got as far as giving him my QTH location and my name, but he never came back, probably because of QSB and the band gradually drying up after dawn.

    Bremerhaven is due east of my QTH and on the North Sea, and I am also not far from the North Sea. Edited to add: As the crow flies, the distance to Bremerhaven is 590 kilometers (370 miles).

    Anyway, clearly the rig is working, and I am thrilled that my very first QSO was with another country, albeit not even remotely DX! I don't suppose there's some high-tech way to track down Bernhardt's real callsign....

    (Edited to add: For those new to this topic, I first passed the UK Radio Amateur's Examination in December 1971, but it has taken me until now to get on the air for the first time....)

    73 de Martin, G3EDM
    Last edited: Aug 27, 2021
    MW0IHW, KO4ESA, G0CIQ and 18 others like this.
  2. SM0AOM

    SM0AOM Ham Member QRZ Page

    Heard part of your QSO with a German station and a CQ on 7030.47 kc about an hour ago.

    A lot of QSB here but signals easily copyable at the peaks on my two-tube RX using some audio selectivity.

    However, there was some instability; "yoop" on the signal, which points to a crystal oscillator with too much feedback which shifts the frequency somewhat due to crystal heating.

    As the oscillator used is a triode Pierce, it uses a feedback capacitor from grid to ground. A larger value means more feedback.

    Try reducing the capacitor to a value that sustains oscillations but no more.

    Anyway, congratulations and 73/

    SA6CKE, KO4ESA, G0CIQ and 6 others like this.
  3. G3EDM

    G3EDM Ham Member QRZ Page

    Hi Karl-Arne,

    Looks like I need to adjust C1 (see schematic below), which fortunately is a small trimmer and easily adjustable.


    Here's a photo. It was taken while the TX was under construction, which is why you will see that some of the connections have not been soldered yet.


    By the way, there's about 240V on the plate of the PA and the meter is showing a combined plate and screen current of 60ma. Does that really mean the TX has a plate input power of 240 x .060 which would be 14W?

    73 de Martin, G3EDM
    KO4ESA, G0CIQ, KN4PUY and 5 others like this.
  4. SM0AOM

    SM0AOM Ham Member QRZ Page

    You have to subtract the screen current
    before the plate input is calculated.

    A reasonable estimate is 5 - 10 mA, so the plate input would be around 12 or 13 W.

    W7UUU, N2EY and G3EDM like this.
  5. G3EDM

    G3EDM Ham Member QRZ Page

    Wow. For some reason I thought my TX was QRP but that is rather more (if you use the standard QRP definition of 5W on CW).

    When I have the "hood off" later today I will double-check the voltage on the plate at key-down. It says 240V on the schematic, but it would be good to know the real value.

    When I was building the TX, the initial version (identical to ARRL schematic) had noticeable chirp, which I could hear even on my completely overloaded RX. This was troubleshooted, at a distance, by N2EY who suggested improving the stability of the B+ power supply by using a resistive voltage divider. This was done, and the chirp went away. IIRC, I also changed the value of a resistor to make sure that the plate voltage was within spec for the 5763 (in my initial "ARRL" build, the B+ was too high, in comparison to the value given in the RCA tube manual).

    73 de Martin, G3EDM
    KO4ESA, G0CIQ, W7UUU and 2 others like this.
  6. K5ABB

    K5ABB Ham Member QRZ Page

    Well done Simon! Time to pop a cork in celebration, you've been waiting 50 years for this.
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  7. W4KYR

    W4KYR Ham Member QRZ Page

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  8. G3EDM

    G3EDM Ham Member QRZ Page

    OK I have found Bernhardt, with a bit of detective work from my notes. I had added a random letter "D" to the end of his callsign. So his call is actually DF6YF. I will send him a QRZ message and apologize for the mangling ... and explain that it was my first QSO.

    73 de Martin, G3EDM
    W1TRY, G0CIQ and N2EY like this.
  9. G3EDM

    G3EDM Ham Member QRZ Page

    Another defect in my transmitter, which is not crucial but causes operator discomfort, is that the transistorized sidetone oscillator is producing loud clicks in the headphones. I suspect it is because the voltage it is drawing from the cathode circuit of the PA is too high; or perhaps I need to add a capacitor or change a capacitor value in the oscillator circuit to get extra smoothing. Time to investigate.

    I know that this circuit does not usually "click" because it is identical to the outboard code oscillator that I use when practicing CW sending. That outboard oscillator is battery-powered (9V) and has a clean tone.

    73 de Martin, G3EDM
    G0CIQ likes this.
  10. WZ7U

    WZ7U Ham Member QRZ Page

    Glad to see you getting it all sorted out Martin. 50 years is quite the wait and I'm honored to be around to see it with you.

    KC7JNJ and G3EDM like this.

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