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Thread: Noise? active antenna for 200 Kc to 200 MHz

  1. #1
    Orca Whisperer PA5COR's Avatar
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    Noise? active antenna for 200 Kc to 200 MHz

    Since i'm mostly active on 160 or low bands and live on the edge of the town, the 77 feet high inverted L with 3000+ feet of radials doesn't make it difficult to put out a decent signal on 160 - 20 meter with the MFJ 998 autotuner fed at the bottom of the L.

    Most of us not blessed with a shack in the woods far from civilisation, and have the problem to recieve, and no place to put up beverages or even a K9AY loop.

    I made a amplified magnetic loop with a long tailed pair of BFW16A ( 1.1 GHz Ft ) transisters, and found the next building project to get even less noise and more usable signal.

    http://pa0fri.home.xs4all.nl/Ant/Act...enna%20eng.htm

    Description there, including schematic diagram, the ina 02186 MMIC can be had on the internutz cheap.
    Rest is junkbox material, for the loop you can also use a 13 feet section of RG 213 if coppertube is too expensive.

    Í oredered 10 of the MMIC's if they arrive the next building project is on the table.
    Last edited by PA5COR; 02-17-2014 at 09:28 AM.
    "If the Republicans will stop telling lies about the Democrats, we will stop
    telling the truth about them." - Adlai Stevenson (1900-1965)
    “I’m not liberal/conservative, I’m anti-idiotarian.”
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  2. #2
    Orca Whisperer PA5COR's Avatar
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    Nobody interested?

    hmmm, maybe i better trot back to the politics section ;)
    "If the Republicans will stop telling lies about the Democrats, we will stop
    telling the truth about them." - Adlai Stevenson (1900-1965)
    “I’m not liberal/conservative, I’m anti-idiotarian.”
    At some point in the last 20 years, the left moved to the center, and the right moved into a mental institution

  3. #3
    Orca Whisperer
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    I could bitch about you posting this, but I thought it was a good link, with a decent project :)
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    http://www.coreyreichle.com

  4. #4
    Orca Whisperer PA5COR's Avatar
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    Waiting for the MMIC's to arrive from my supplier, till them making the pcb, get the parts from the junkue box ;)
    Remembered i'm a ham as well, soldering iron(s) were cold too long.
    "If the Republicans will stop telling lies about the Democrats, we will stop
    telling the truth about them." - Adlai Stevenson (1900-1965)
    “I’m not liberal/conservative, I’m anti-idiotarian.”
    At some point in the last 20 years, the left moved to the center, and the right moved into a mental institution

  5. #5
    'Grumpy old bastid' kb2vxa's Avatar
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    Some years ago I made a couple of preamps with those bad boys. Two in cascade was WAY too much gain for 2M weak signal work, one was quite enough.

    Your garden loop rather does stand out... like a tree in a forest.
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  6. #6
    Mystical Drummer NY4Q's Avatar
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    Quote Originally Posted by PA5COR View Post
    Nobody interested?
    Easy now, calm yeself. I (and many others) may not have seen this yet. I'm interested because I'm setting up a SDR and need a good low-noise active system. I'll check it out.
    أبدا ستعمل تعطيك ما يصل

  7. #7
    Mystical Drummer NY4Q's Avatar
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    Very good. I just read and listened to the MP3s. I built one of these years ago for my summertime 160m activity and it was fabulous, although mine was not an active antenna and I used CATV cable from the cable company (75 ohm hardline).

    I have a recording somewhere that I'll post for you to hear the difference. I switched from a full-size 160m dipole to the RX loop in the recording and it is scary how great that thing cleaned up the noise.

    So, I think I'll build up the same system that I had before except I'll add that amp design. Veddy nice. Thanks.
    Last edited by NY4Q; 02-18-2014 at 08:21 PM.
    أبدا ستعمل تعطيك ما يصل

  8. #8
    Orca Whisperer PA5COR's Avatar
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    Cheers, always pleasing to b able to help.
    Running a amplifid loop now of own design, i just wanted to try this one out.
    Have several pieces coax left 15 millimeter thick ( Ecoflex 15) that i can use for the loop.

    For 2/70 i used the MGF 1300 series GaAs fets as pre amps, well build you got an incredible low noise and good gain.
    If i turned my beams towards the sun i could hear the noise come up.
    Last edited by PA5COR; 02-19-2014 at 03:53 AM.
    "If the Republicans will stop telling lies about the Democrats, we will stop
    telling the truth about them." - Adlai Stevenson (1900-1965)
    “I’m not liberal/conservative, I’m anti-idiotarian.”
    At some point in the last 20 years, the left moved to the center, and the right moved into a mental institution

  9. #9
    Mystical Drummer NY4Q's Avatar
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    I just snatched up 5 INA01286's on eBay for $7 shipped.
    أبدا ستعمل تعطيك ما يصل

  10. #10
    Orca Whisperer PA5COR's Avatar
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    I got 10 from Israel ( of all places) for 10 dollars, 4 bucks to send them over, waiting to see them arrive....
    "If the Republicans will stop telling lies about the Democrats, we will stop
    telling the truth about them." - Adlai Stevenson (1900-1965)
    “I’m not liberal/conservative, I’m anti-idiotarian.”
    At some point in the last 20 years, the left moved to the center, and the right moved into a mental institution

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