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

  1. #11
    Mystical Drummer NY4Q's Avatar
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    Quote Originally Posted by PA5COR View Post
    I got 10 from Israel ( of all places) for 10 dollars, 4 bucks to send them over, waiting to see them arrive....
    Nice! I'm gonna start on the loop after work today. Here's the file I mentioned earlier. The first three seconds is on a full-size 160m dipole, the last three are on the RX loop. It's a short clip, but you can hear the noise vaporize. This was recorded in the afternoon and in Summer and my buddy (WA4GEG) is about 130 miles from me.

    http://168.8.96.100/~pheaton/wa4geg.mp3
    Last edited by NY4Q; 02-19-2014 at 05:42 PM.
    أبدا ستعمل تعطيك ما يصل

  2. #12
    Orca Whisperer PA5COR's Avatar
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    That is indeed a remarkable difference.


    My current homebrew amplified loop can do the same under difficult circumstances, but not always.
    Other parts are collected, will cut out the pcb tomorrow and put the other parts already on it, till the MMIC arrives.
    Loop from the coax will be made in the weekend.
    "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. #13
    Pope Carlo l NQ6U's Avatar
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    Quote Originally Posted by PA5COR View Post
    I got 10 from Israel ( of all places)
    I tried one of those in a AM BCB radio I built. It worked okay until I tried to listen to KPIG in Santa Cruz (California). It just wouldn't let me tune in for some reason.
    All the world’s a stage, but obviously the play is unrehearsed and everybody is ad-libbing his lines. Maybe that’s why it’s hard to tell if we’re living in a tragedy or a farce.

  4. #14
    Mystical Drummer NY4Q's Avatar
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    The MMIC data sheet has some good tips on the build plus a board layout if you want to etch it.

    http://www.datasheetcatalog.com/data...NA-02186.shtml
    أبدا ستعمل تعطيك ما يصل

  5. #15
    Orca Whisperer PA5COR's Avatar
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    As usual the first thing read about the MMIC, building if in H.F. type building wise is mandatory.
    Short connections, good grounding of both planes etc...;)
    "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

  6. #16
    Mystical Drummer NY4Q's Avatar
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    I received the MMICs on Saturday. Now to get to etching. One thing on the schematic, the "15" cap on the output of the MMIC box. I'm gonna assume that's a mistake on the drawing?

    Or is it meant to be 15pF?
    Last edited by NY4Q; 02-23-2014 at 08:49 AM.
    أبدا ستعمل تعطيك ما يصل

  7. #17
    Orca Whisperer PA5COR's Avatar
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    15 PF it is, meant to keep very high frequency oscillations away, has no effect on the HF amplification, just stabilising the MMIC.

    You will find that 15 PF back in the decoupling of the + rail before the 470 micro Henry inductor.
    Planning to replace that by a torroid and teflon coax wound around it for decoupling as further up at the bottom of the article is described.
    In stead of the torroid you can also use a small section of a ferrite bar.
    Last edited by PA5COR; 02-23-2014 at 09:54 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

  8. #18
    Mystical Drummer NY4Q's Avatar
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    Cool; yep anything that wide (BW wise) will need anything above HF shorted to ground. I've drilled my board and am now administering the finger polish (yep, I"m high tech - haha).
    أبدا ستعمل تعطيك ما يصل

  9. #19
    Orca Whisperer PA5COR's Avatar
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    RFC1: Mantelstroom filter, ringkern 4C4, 14mmØ, 9 windingen

    http://pa0fri.home.xs4all.nl/Ant/Act...enna/rfc-s.gif

    Last edited by PA5COR; 02-23-2014 at 03:58 PM.
    "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

  10. #20
    La Rata Del Desierto K7SGJ's Avatar
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    Quote Originally Posted by N4BBQ View Post
    I received the MMICs on Saturday. Now to get to etching. One thing on the schematic, the "15" cap on the output of the MMIC box. I'm gonna assume that's a mistake on the drawing?

    Or is it meant to be 15pF?
    How do you make your boards?
    A clear conscience is usually a sign of a bad memory

    RIP ALBI-W3MIV RIP RUSS-W5RB RIP BOB-VK3ZL





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