Non-Friendly / Non-Permissive Environment: HF Operation

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KI5QMP, Sep 14, 2021.

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  1. WB5YUZ

    WB5YUZ Ham Member QRZ Page

    2X
     
  2. AK5B

    AK5B Ham Member QRZ Page

    Not to further veer off course here but I must mention that I have often suspected the same---I live in #30 zone (best) on the FCC map---but my "soil" is really 99% sand! When I drive several miles inland, though, I can easily see the agricultural fields of freshly tilled blackland clay that is so conductive. ;)

    I won't complain, though, as I'm a little more than a mile to the nearest saltwater, the best soil on earth! :D
     
    M0AGP and WB5YUZ like this.
  3. AK5B

    AK5B Ham Member QRZ Page

    Good points, John---Only I will add that the "best antenna" is actually a system of various types of antennas along with a good switch---in an ideal situation, of course.

    73,

    Jeff
     
  4. KA4WJA

    KA4WJA Ham Member QRZ Page

    In regards to reducing noise levels, etc....just some personal data here.

    In my temporary locale, with just an 80m dipole at 12' - 18' high, I have a local / neighborhood noise source (not in my house), centered on 3775-3780khz, and approx. 100khz wide....daytime this is at about -95dbm to -97dbm (roughly S-5 max) in my normal SSB bandwidth, and is reducible down to below S-3, with noise blanker....at first I was frustrated that it's not further reducible, as the TR-7 noise blanker took an S-8 / S-9 impulse noise down to just below S-3 (-108 to -109dbm), this spring....but, oh well, different noise -- different noise signature -- different result...then, of course I realized that the daytime natural noise level even here in quite residential area, with a salt-water inlet / river estuary in the backyard, isn't much lower...(I do find my daytime noise level at the very top of the 75m band and just above 4mhz to be about -112 to -113 on average)...so, no worries...but, I digress.

    Of course, my operating is at night....and here, it is usually good ole' mother nature that governs my noise levels....on a good "quiet night" earlier this year, I might have a noise floor of S-3 to S-4, which isn't bad for a residential locale (actually pretty close to the "ITU quiet rural" level)! But...

    But, typical nighttime 80m noise floors here in Florida are quite high...in wintertime, the occasional lightning static crashes even in winter and early spring can be S-7+, and distant noise (natural and man-made) can make your noise level hover around S-3 to S-4, up to S-5 or so....

    And summertime....well, summertime 80m static crashes here in Florida, start at about S-8 to S-9, giving you an almost constant noise floor of about that, S-8 to S-9...with crashes every second or two 20db over S-9, and every 5 to 15 seconds 30db over S-9....so...So, operating 80m, summertime in Florida usually means either suffering with crashes or running an amp (usually both!)!

    {fyi, my noise level here at my temp location (using the 80m dipole, on other bands, as receive antenna) is actually quite good....when listening to 20m signals of S-9 to 10-over S-9, my noise level is S-0 to S-1....and, when listening to some locals on 40m daytime, with signals of S-9 or so, my noise level is S-1 or less....and, fyi, I don't have exact calibration numbers of my S-meter below S-3, but I suspect it's pretty close (see my QRZ page, https://www.qrz.com/db/KA4WJA for details and pics of my S-meter readings).}

    The reason I'm relating this personal receive noise level data / anecdotal info (along with my repeatably good results in barefoot/65 watt operations), is to show that if you can control your QTH's receive noise floor / noise level, you can have good results from residential areas on 80m, even in summertime. Just need to keep the noise levels in check. :)

    I hope Tyler finds this useful....if not, well I'm keeping my mind occupied while in surgical waiting room. (older brother)

    73,
    John, KA4WJA
     
  5. K0DUC

    K0DUC Ham Member QRZ Page

    My temporary setup for 80 meters is a center fed dipole only 16 feet off the ground. Hammering the ND and SD nets with good signal, and tonight I checked into a net in Missouri.

    Waiting for the grass to go dormant to re lay the radials for the Hustler, and figuring out a permanent place for this center fed dipole. But until then, I'll work what I can. Not a great setup, but it isn't exactly dead.
     
  6. WA7F

    WA7F Premium Subscriber QRZ Page

    Wow, I just Googled your address. Your neighborhood seriously needs some trees, bushes or at least privacy fences. Given the lack of cover I suggest that you look into a flag pole vertical antenna. Maybe add a BOG receive antenna once the flagpole is up and running.
     

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