Rockmite 40 Chinese Clone

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  • Опубліковано 27 лис 2024

КОМЕНТАРІ • 23

  • @graememorgan6120
    @graememorgan6120 Рік тому +1

    Great work George

    • @TheArtofEngineering
      @TheArtofEngineering  Рік тому +1

      Thanks Graeme…. Might work u on it?? You will need to turn up the gain!! 😝😝73

  • @MarkPaile
    @MarkPaile Рік тому +1

    Got the same kit built and working; receiving well and around 5 watts output. Being honest, I think the gods of kit-building were smiling on me.
    I'd echo the suggestion that this kit is not for the faint-hearted. in my opinion, builders without an L, C, and R meter to weed out the 'off' components will be lucky to get the kit operational. As noted below, some of the components off by 20% or more.
    What was a bit of head-scratching were the 'spare' components left over! Why do I have two 51 ohm resistors? (To make a couple of dummy loads?) I can cope with missing components better!
    The Chinglese 'instructions' for setting up the keyer are virtually incomprehensible, but eventually I got the iambic keyer to play ball. ... Bruce.

    • @TheArtofEngineering
      @TheArtofEngineering  Рік тому

      Thanks fer the comment. I guess the uncertainty is part of the fun! 😃 73 de VK2AOE.

  • @johnc3403
    @johnc3403 Рік тому +1

    Really looking forward to the microwave oven derived CW transmitter. I have a transformer myself, just waiting for a project . John EI5JS

    • @TheArtofEngineering
      @TheArtofEngineering  Рік тому

      I have never built with tubes…. But it is on my bucket list! How hard can it be?? 🥹⚡️⚡️⚡️I did build my PSU using 2 of them!
      Linear 20A 13.8v DC HAM SHACK PSU - Made with rewound microwave transformers@TheArtofEngineering
      ua-cam.com/video/uV5gD_t0V6w/v-deo.html
      73 de VK2AOE

  • @keithflesser1533
    @keithflesser1533 Рік тому +1

    Good luck with it mate, those kits are probably not a good idea for the faint hearted.

    • @TheArtofEngineering
      @TheArtofEngineering  Рік тому +1

      Yes…. The original kits were usually good…. Clones ?? Parts often dodgy! 73 and thanks for the comment de VK2AOE

  • @JensGrigull-ij6fd
    @JensGrigull-ij6fd 11 місяців тому

    Hi I have the same problem. Only about 0.5 Watt output.
    There is a transformer in the circuit 1:4. This means the two windings are primary and the eight windings secondary.
    Otherwise it would be a 4:1 transformer with eight windings primary and two windings secondary.
    Is this correct?
    The fault is in the power amplifier for sure.

    • @TheArtofEngineering
      @TheArtofEngineering  11 місяців тому

      The Toroids in the LPF are also 💩😜. Lossy and just plain bad ! Happy new year!

  • @michaltulach7151
    @michaltulach7151 Місяць тому

    May I ask you what type antenna is best for this kit? Is any 49:1 transformer needed?

    • @TheArtofEngineering
      @TheArtofEngineering  Місяць тому

      It is designed to operate into a 50 ohm load (like most modern ham and other comm gear). So if you used a decent Center fed resonant dipole fed with 50 ohm coax it would work well. A 49:1 would be used for an end fed half wave as the feedpoint impedance at the end is high. May I suggest if you want a GREAT kit look at QRP Labs and buy one there! The instructions are awesome, the rigs are too! CARTENNA QRP portable @TheArtofEngineering
      ua-cam.com/video/9WEV6Hr6o7A/v-deo.html
      QCX mini - Say hello to my little friend.
      ua-cam.com/video/cx-Qng-ySu0/v-deo.html

    • @michaltulach7151
      @michaltulach7151 Місяць тому

      @@TheArtofEngineeringThanks for reply, I just bought Super Rock Mite from Aliexpress. It has the 50 ohm output and around 5W of output power. So you think the classic half wave dipole would be the best option for the maximum range? The coaxial has 50 ohm but the dipole has 75 ohm which is not the same value. It doesn't have to be adjusted? Sorry if I have dumb questions, I'm new to RF.

    • @TheArtofEngineering
      @TheArtofEngineering  Місяць тому +1

      @@michaltulach7151 Not a dumb question! There is no “best” antenna only “next” antenna! 😂 The fun is in the experimenting. Usually higher is better and you want a low angle of radiation. So a vertical is a simple antenna with a good takeoff (shallow) angle. As for impedance you are correct but it varies with height and ground conductivity. Some people use a 1:1 balun (but not a necessity). Many fuss about trying for 1:1 SWR (just get it below 2!). Get a nano VNA and use that to get a good SWR. Here is a simple vertical I made for 40/20m (there are heaps of dipole making vids). 73 and welcome to the ham madness!!! 😂
      DX Vertical L Antenna for 20m and 40m
      ua-cam.com/video/YEFuJkD_uLg/v-deo.html

    • @michaltulach7151
      @michaltulach7151 Місяць тому

      @@TheArtofEngineering Yeah I experienced a lot of experimenting while I was building a simple aircraft band receiver a few months ago. But the experimenting is fun. At first I wanted to build the vertical antenna but when I discovered It will need to be really long I changed my mind and I want to build horizontal such as dipole. I do not have much space for vertical antenna and I wanted it to fit in my attic (which is around 13 meters above ground) so it would not be exposed by UV. But thanks for recommendation maybe one day I will get to build vertical antenna which should be more efficient (if I know that correctly). I will probably build a simple dipole. But both of the arms have to be around 10 or 11 meters long. Since I have only a rectangular space of 3×15 meters and the feed point has to be in the middle of the 3m long wall, I think I will just bend the arms in U shape to fit there. Do you think It is a good idea or I should not do it?

    • @TheArtofEngineering
      @TheArtofEngineering  Місяць тому +1

      @@michaltulach7151Nothing to lose! You could load it with a small coil in each arm to shorten it a little? Or if you want to really go down a rabbit hole investigate magnetic loop antennas 😂😂 73 fun antenna play !

  • @MidlifeRenaissanceMan
    @MidlifeRenaissanceMan Рік тому +1

    [Edit] I told a lie. The $8.74 was for the Forty-9er. These Rockmites were about $16 each and they are meant to put out 8W !!!!…..like that Beofeng thing
    I only have one of the Forty-9er kits….
    ----
    I had a look and that kit was $8.74 plus $1.19 shipping in aussie roubles.
    The toroids are known to be less than optimal in these kits and are responsible for low output power and / or bad mismatches. Then again, the components could be fake / rejects.
    I’ve got the other one. I might have a go at putting it together and see how it performs.
    I need to build a 40m poke-out-the-window-tenna so I can test it on the bench
    What happened to the -spiciest- Pixie I gave you ???

    • @TheArtofEngineering
      @TheArtofEngineering  Рік тому +1

      Yes we can do uDX Kogs to the inner West😆🤣🤣dit dit

    • @MidlifeRenaissanceMan
      @MidlifeRenaissanceMan Рік тому

      @@TheArtofEngineering I've dug it out, along with the Pixie I grabbed for you. Also found some old school larger style crystals for 7005, 7010 and 7015 I found online and purchased. Not the ancient ones with the removable covers you can sand down, but the larger ones they used in the 60s.
      Depending on my day today, i might give it a go. Had the charge on my iPhone fall off a cliff. Died during my second coffee, so I'll fix that before anything else. Got the last battery from WES
      Some quick calculations put the 5m circumference loop poke-out-the-window-tenna at around 18%, so more than 1 S point down operating from my work bench
      The VK2RH RBN isn't too far away so I can get an idea of how effective it is...
      But I have work to do first.
      I'll keep yo in the loop.....so to speak
      73 dit dit

  • @DonzLockz
    @DonzLockz Рік тому +2

    Atleast it works, albeit a tad extra low qrp. You have the power and technology... and patience to fix it though. Lol
    On a side note, the audio levels jump around alot, especially the intro music on headphones. Maybe you can attenuate it a bit. :)

    • @TheArtofEngineering
      @TheArtofEngineering  Рік тому +1

      Thanks Don…. Yes I was a bit worried about the levels! Thanks for letting me know. I’m waiting on some transistors to maybe up the transmit power. 73

  • @G0NMY
    @G0NMY Рік тому

    I built one a while back and the component quality was rubbish, most caps were of poor quality.
    Also the red ferites did not seem to tune very well suggesting that they were cheap and not good quality material.
    Your Milage May Vary.
    Again you get what you pay for I suppose. But hey BD139 are ok and will get you on the air.
    72 Mark G0NMY

    • @TheArtofEngineering
      @TheArtofEngineering  Рік тому

      Yes…. Always hit and miss with the cheap stuff…. Fun to play and see if you can get a QSO though. I wanted something to test the progrock from QRP Labs on (I have no rockbound rigs). 73 de VK2AOE