Discussion in 'Amateur Radio News' started by K9EID, Jul 16, 2017.

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  1. K9EID

    K9EID Ham Member QRZ Page

    The students only "get the heck" scared of them if we fail to teach them about the HV circuits. Solve that by teaching the
    circuits and where NOT to stick your fingers ! Thanks for teaching..
  2. KE0GHU

    KE0GHU Premium Subscriber QRZ Page

    thanks Bob, this has been a great learning experience for me. I recently fixed up a old U-Test-M tester (see photo) like the one that my dad wb6hny used to work on when my grandfather owned a business in So Cal called Ettco Distribution that places, maintained and stocked these testers in the southwest. So this gives me a excuse to use the tester...also I am looking to restore some of old USSAF radio sets (see photo for the collection) so all this is helping understand how they all come together!

    Attached Files:

  3. JP7MBO

    JP7MBO Ham Member QRZ Page

    Finished the power supply and working on the preamp. Tomorrow going to get the rest of the parts. Can't wait to build the transmitter!!! Can I mod it to make it a 10m transmitter?
  4. KB9EGI

    KB9EGI Ham Member QRZ Page

    Been working with high voltage since my very first BC-312 receiver. I was 12. Had my first high voltage mistake whilst holding on to the ground clip of the second anode probe on an RCA color set. That was exciting, and at 60 years old - something I will never forget. Remember, "Other hand in the pocket" working with any live power. Period. Teach personal responsibility again in the schools so that fear won't be the ruler. Bob, you're right! Teach where not to touch, AND WHY!
  5. W9YAC

    W9YAC Ham Member QRZ Page

    Based on the PS schematic I saw on Ham Nation, and since this is meant as a learning experience, I have two suggestions.

    Move the power switch from the neutral side of the transformer primary to the line side by the fuse. The neutral should not be switched.

    Add a 3-wire power cord and ground the frame of the transformer.

    The danger is that the transformer could fail with an internal short. With the neutral open at the switch, and with no equipment grounding conductor, you could become the return path.

    Rich W9YAC
  6. N4JGO

    N4JGO Ham Member QRZ Page

    This has been a fun project for new builders as well as old timers. I totally agree with what you are suggesting. That is exactly what I did on the one I am building, plus I added terminal covers to boot. I added pictures to my QRZ page.
  7. W6MQI

    W6MQI Ham Member QRZ Page

    I'm not presently building this project, but I too agree switch the hot side not the neutral.

    Bob is Ham Nation going to have a on air gathering of all the pine board transmitters or a mini pine board contest with each transmitter listed with a special PB# work 10 pine board transmitters get certificate? Maybe that will spur some interest in people to get started in home brewing.
    Last edited: Jul 21, 2017
  8. K4ACS

    K4ACS Ham Member QRZ Page

    I took a liking to technology when I was about two. My Dad built a "New for 1969" Heathkit GR-180 color TV as our Christmas present in 1968 and I couldn't wait for the magic glow to happen. Later he built an SB-401/303 (SS receiver) set with the SB-600 and SB-630 accessories I now have and am restoring. From his teachings on electricity to my own education and experiences with current based technology that solid state uses, I'd much rather use high voltage tube equipment. Remember, ignorance and current are what kills, not voltage. Learn how to handle high voltage rather than avoid it. It just might save a life.

    I look at it this way, the state of solid state is so fragile that if you see mushroom clouds on the horizon, tube radios will most likely be the only radios working if there's anyone left to communicate with. By the very nature of discreet electronic design, they were naturally hardened against Alpha particles and flew on every space mission and every satellite launched and still do. Tube finals are used on every broadcast satellite in orbit because of their durability and reliability. When all else fails, vacuum tubes can be relied upon.

    Keep up the good work Mr. Heil. Teaching younger generations how to respect and use electricity through experimentation and working examples is a big plus!

  9. JP7MBO

    JP7MBO Ham Member QRZ Page

    I got my power supply working!! Thanks Bob!

    Attached Files:

  10. OH2FFY

    OH2FFY Ham Member QRZ Page

    Easy question to answer.
    Back in the old days , most Hams knew something about radio electronics and electricity.

    Now days most Hams know about contesting , prepping , storm spotting , SOTA , repeaders , boy scouts , compewders - - almost everything EXCEPT for radio.


    With more than half of the US Hams being at Tech class level , with essentially no knowledge of electronics ,, I think it is GOOD that they don't play with high voltages.

    gregW:) OH2FFY

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