Lopsided signal reports

Discussion in 'Straight Keys - CW Enthusiasts' started by N0MAP, Feb 9, 2018.

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  1. WB5YUZ

    WB5YUZ Ham Member QRZ Page

    Are you renting, or do you have a condo association? If you were free to remodel (I would remove the bricks, put the radials under them, and put them back), you could put an adequate radial field in at that location! I don't think I'd try an inverted "L," because you don't have much linear room for the horizontal portion; but I would definitely put in a trap vertical, fan vertical, or similar, to supplement your loop.

    About that noise level: if you can get the vertical away from the house, and feed it with a good choke (don't just wind up a few turns of coax and expect it to work well on 40 or 80m!), there is a good chance that you will see a perhaps one or two S-unit drop in noise level compared to a very low horizontal loop with the house inside the circumference of the loop, or one leg of the loop passing very low over the house.

    Well, in that case it has to be admitted that this antenna is working about as well as its going to. If you can be satisfied with it, then so be it. But you can do better if you want.
     
    Last edited: Feb 20, 2018
  2. N0MAP

    N0MAP Ham Member QRZ Page

    I own it, but the porch and walkway are concrete. I could bust them up and redo, but my backyard is alley side. So my row house of 2.5 stories on one side, back yard, alley, back yard, another rowhouse. It's basically a brick canyon filled with all the utility lines for the rowhouses. Sub optimal for a ground mounted vertical at best. Remodeling my back yard for the possibility of an S or 2 noise reduction doesn't sound like a good idea.

    I have been toying with the idea of throwing a thin end fed wire over the top of the length of my whole house and running it all the way to the other end of my back yard. That would get me a ~115ish' line, the radiating portion of which would be up 40' (and out of the brick canyon). I am sure I'd have to replace it 3x a year, but that wouldn't be so bad.

    Anyway, thanks for the thoughts. I'm also an avid astronomer -- another pursuit which is best practiced outside of the broad spectrum radiation pollution that is the Chicago metro area :D
     
  3. AA4OO

    AA4OO XML Subscriber QRZ Page

    Magnetic loops are a pain to operate but would probably answer your noise problem.
     
  4. N0MAP

    N0MAP Ham Member QRZ Page

    Right. I've heard they deal much better with noise. This was actually the route I considered when I was freshly ticketed and still thinking I could make a decent shack at home (i.e. 6 months ago :D). One thing that has changed since then is that I am QRP almost 100% of the time these days (most of the time 5W for CW ops). I wouldn't have used an indoor loop up running 100W, but I need to rethink that given QRP. My shack is on the 2nd floor, so it would a little elevation too (enough to get it out of the brick canyon).

    Thanks for reminding about that. I am going to do some research on making one. I had a plan before, but it was for a 100w one. I suspect it'll be easier (and cheaper) for a tuning capacitor that only needs to handle 10w max.
     
  5. N0MAP

    N0MAP Ham Member QRZ Page

    whoops double post
     
  6. N0MAP

    N0MAP Ham Member QRZ Page

    Wow, I must have angered the ether gods with my hubris. A large chunk of falling ice took out my horizontal loop last night. I guess I am going to be investigating qrp mag loops quicker than I thought!
     
  7. AA4OO

    AA4OO XML Subscriber QRZ Page

    If you have a gutter with a downspout you may already have a inverted L at your disposal. I worked a ham in Colorado sporting a rain gutter antenna. You just need to bond all the joints and put a small radial field at the end of the downspout. SWR varies a bit with the weather but it's certainly a stealth antenna.
     
  8. G0IIK

    G0IIK Premium Subscriber QRZ Page

    Hi, I can operate my Begali Intrepid at around 12 wpm or less, but the down side is that the Intrepid cost me about $700, I usually like to run about 24 wpm whan rag chewing.
    The thing that annoys me most is the guy who puts out a cq call at 18/20 wpm then when answered immediately goes off at 28/30 wpm. I don't get the point. Maybe it's the "I can send faster than you" thing. So often more speed means more errors!
     
  9. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    First, 100W into an indoor loop isn't hazardous at all.

    I've done this too many times to count, not at my home but at hotels, motels, campgrounds, almost anywhere away from home. If you do the calculations per the FCC formula, on 40m you'd have to be within a couple of feet of the antenna; on 80m, you'd need to be touching it; on 20m, a couple of feet more. Doesn't start to become nearly "hazardous" until you get up in the VHF spectrum. And of course the list of those who died from RF exposure at the 100W level is such a short list it doesn't exist.

    So, I certainly wouldn't fret about that for even one second.

    However, another point to ponder: STLs for transmitting require adjustment and are very high-Q if made well, so they require a lot of adjustment; however, "receiving" loops are way more forgiving and can be broadbanded so they require no tuning at all, but can still null noise sources very well. You just need a separate transmitting antenna, which can be whatever you can manage.

    I use a "separate receiving loop" on 40-80-160m quite often (maybe almost all the time). Signals are not nearly as strong as on my bigger antennas used for transmitting, but S/N ratios can be much better. An S1 signal over an S0 noise level is really easy to copy on CW. An S9+20 dB signal over an S9+19 dB noise level may be impossible to copy.

    Transmitting is all about e.r.p., but receiving is all about S/N, and small receiving loops are very directional and allow noise nulling really well, unless the noise is coming from "all directions," which would be unusual.
     
  10. N0MAP

    N0MAP Ham Member QRZ Page

    Very interesting. So what sort of gear arrangement do you use to allow listening via one antenna and transmitting on another?
     

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