Using FT8 to demonstrate Antenna Orientations

Discussion in 'Amateur Radio News' started by KM9G, Oct 6, 2021.

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  1. 2E0TWD

    2E0TWD Platinum Subscriber Platinum Subscriber QRZ Page

    I see nothing here that has caused the outrageous response from Mr. Chip.
    M1WML and KC7ZXY like this.
  2. W1YW

    W1YW Ham Member QRZ Page

    Stop trolling. Part 97 applies to US amateurs.

    For us, our Part 97-defined mission to 'enhance the radio art' means we should pursue the multitudinous resources we have available to us --most are FREE!--to understand the basics of antennas and ionospheric effects--and then take it further. Indeed, many of these basics are part of the test question base we use in order to obtain our licenses. That body of resources makes us a 'pool of those skilled in the radio art'--when we take advantage of it. The scientific method is a basis by which one 'enhances the radio art' as an applied science.

    In this case we have an OBSERVATION which is confused with an EXPERIMENT--and a lack of sufficient basis to claim the outcome so posed.

    THAT is: 'what's the fuss?' That's why KO0U, for example post 22, made his comment.

    Look--if a US ham (for EXAMPLE) wants to stick a shopping cart in a tree and make it an antenna and then boast about how they used FT8 to 'talk' to Lower Slobovia, that's a personal anecdote of limited interest (yes someone did this 'cartenna' a decade ago) . But we never saw a video on a prominent link about it.

    KM9G is going in the right direction to do a relevant antenna comparison. But this video, IMO didn't fly.

    Have a great day.

    Chip W1YW
    Last edited: Oct 9, 2021
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  3. WA6VVC

    WA6VVC Ham Member QRZ Page

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  4. WA6VVC

    WA6VVC Ham Member QRZ Page

    WOW... Wasn't looking to push that that button. Just wanted to get a better understanding with my limited knowldge and felt I had a little handle on some of the antennas tested.
    Then share the a really BIG test chamber near by. Maybe I did read it right and somebody else missed my point. Have a hamming good day.

    M1WML and KC7ZXY like this.
  5. W1YW

    W1YW Ham Member QRZ Page

    The best one can do at HF is have the three antennae separated by many wavelengths, on the same ground and topography, same coax length and do real-time switching : A/B, A/C comparisons (in this case) . That will tell you the best antenna AT A SPECIFIC ionospheric condition at a SPECIFIC time for a SPECIFIC path.

    In fact, to get precise gain differentials you need to set one antenna--the 'strongest'-- and then use a precision attenuator on RX to measure the differential for the others. This does not work with FT8, and likewise does not work with merely looking at an S meter, for example. Why? because the RSSI roundoffs leads to huge 1-2 dB+ measurement uncertainties, when the typical antenna gain differentials or only a few dB (if that)... Just think about the poor accuracy of the 'bars' on your phone as an extreme example.

    Never trust an RSSI measurement (if at all) without a differential and a precision attenuator in line. And never measure at different times (beyond real time switching).

    Chip W1YW
    Last edited: Oct 9, 2021
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  6. KO4CES

    KO4CES Ham Member QRZ Page

    Interesting question, and without engaging in all the technical mumbo-jumbo, my 40 meter pattern appears as a teardrop, similar to what you show -- resulting in the same area of the United States.

    I'm in Daytona Beach, Florida, and my EFHW matchbox begins in the south (Miami) and points towards the north (New York). On average, I also have a few reports behind me, in South America, and a few to the right, in Europe; additionally to the left, in California and Washington.

    20 meter shape is a solid 180 degrees across the United States and into Europe -- similar to a Japanese fan. Occasionally, reports come from Hawaii and Australia.

    Antenna: Homebrew 40' 40/20 EFHW
    Comparison Antenna: Bushcomm SWE-100
    Radios: FT-991A at 10-25 watts; IC-705 at 5-10 watts
    ALC: Always below red
    FT8 Transmit Power Level: Varies between radios, -16dB to -20dB

    I hope the information helps you. Your videos are always appreciated.
    M1WML, KC7ZXY and 2E0TWD like this.
  7. DO1FER

    DO1FER Ham Member QRZ Page

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  8. W1YW

    W1YW Ham Member QRZ Page


    Please do not put YOUR comments inside MY quote.

    That is not what I said at all. You should not attribute your comments to me.

    Again, there is no value whatsoever in comparing the three antennas as KM9G asserts. I just went into detail why. I even told you (a way) how to do it (see post #55) properly (albeit with uncertainty in the data values).

    Measurements are not a basis for 'what I feel'.

    Spock - How Do You Feel? - YouTube

    There are not fifty different way to measure properly in this case. And we learn nothing by pretending a wrong way is 'ok' as an 'experiment'. If you want to use that as an incentive to learn way(s) to do it correctly, well, that's a very different story.

    That isn't how the video presented the objective. And THAT is 'what is the fuss'...

    Jeez, can we do something right on this thread:0)?
    Last edited: Oct 9, 2021
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  9. 2E0TWD

    2E0TWD Platinum Subscriber Platinum Subscriber QRZ Page

    My comment was regarding your “Trolling” of WA6VVC, you should apologise for your outright rude response. I have no interest in whether you liked the video or not. Apologise for your hateful rant.
    M1WML and KC7ZXY like this.
  10. W1YW

    W1YW Ham Member QRZ Page

    No apology needed. No trolling done.

    After he clarified his query I fully answered it accurately and cordially in post #55.

    Now stop trolling... please read before you lead.
    M1WML likes this.

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