Announcement

Collapse
No announcement yet.

best antenna

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • aesoprrp
    replied
    Originally posted by abcd567 View Post
    Not necessay that every install gets 250+ nm. Only if no high rise building is obstructing the view of horizon, and antenna can "see" the horizon. .
    Totally understand. My maximum theoretical range is about 220nm depending on the direction. I live in a city very close to some mountains on two sides. So I get great range to the South and West (so far up to ~190nm with the various antennas I've tested, including the FA antenna), but less than 50nm to the North and East (unless the contact is very high, then maybe up to 80nm).

    I'll give that design a try this coming weekend!

    Leave a comment:


  • abcd567
    replied
    Originally posted by aesoprrp View Post
    250+ nm?! Consider it done.
    Not necessay that every install gets 250+ nm. Only if no high rise building is obstructing the view of horizon, and antenna can "see" the horizon. Also the length of coax between antenna and DVB-T should not be long.

    My apartment (inside which Quick Spider is located) is about 60 feet / 20 meters above road, and I get 250+ nm only in unobstructed directions. In directions where there are high rise buildings, I get much less max range.

    The length of RG6 coax between my Quick Spider and the DVB-T/RPi is about 12 feet / 4 meters.

    It is worth trying Quick Spider. Whatever your location and height, the Quick Spider performs NOT LESS than the SO239 Spider at same location and height.
    Last edited by abcd567; 2019-02-25, 22:45.

    Leave a comment:


  • aesoprrp
    replied
    250+ nm?! Consider it done.

    Leave a comment:


  • abcd567
    replied
    .
    .

    QUICK SPIDER - No Soldering, No Connector

    .
    .
    Last edited by abcd567; 2019-02-25, 20:37.

    Leave a comment:


  • aesoprrp
    replied
    Two more questions for you hardware experts...
    • How much of a difference does RG8 coax make over the more commonly available RG6? I know the technical difference of 75ohms vs 50ohms, but I don't know how that difference is seen for ADS-B frequencies.
    • I've had limited success with soldering copper wire to a SO-239 connector. The solder doesn't take very well. Do I need additional flux? Maybe some cleaning solution on the connector first?


    Setup is coming along great... lots of planes so far. Just perfecting and building a second site.

    Leave a comment:


  • Rooster
    replied
    1/4 wave antenna is very small and light... mount it on a bit of plastic conduit (or whatever you can find)
    Maybe hot glue would attach it to the brickwork in a few places ?
    Or maybe you could simply stand a "spider" in the guttering... even on a window sill would capture some aircraft.
    I have in the past used aluminium security tape to make antenna for amateur radio - this is self adhesive, and just sticks to the glass (its used in burglar alarms systems to detects a broken window)
    If theres a down pipe nearby, construct a coco and waterproof it, then simply wedge it into the top of a down pipe !

    There are dozens of ways to skin this cat ! LOL

    Leave a comment:


  • aesoprrp
    replied
    Originally posted by 1090 MHz View Post
    This is the one I use, Silicone Self-sealing Tape: https://www.homedepot.ca/en/home/p.t...00104039.html#
    It's in the electrical section.
    Thanks!

    Also, I’m looking for input on mounting solutions. Basically I need to figure out how to securely attach my antenna mast to the side of my building without drilling any holes (renting an apartment).

    The outside of my building is brick, and the brick protrudes about 1/4” from the mortar. I found some “brick clips” (like this: 4 Metal Brick Clip Fastener Hooks ) meant for hanging pictures, so my first idea is to somehow attach a PVC pipe to the brick clip, and then attach the mast to the PVC with either an elbow joint or something similar. The idea here is to get the antenna out away from the side of the building, ideally about 8” or so. However, I’m not sure that the brick clips are sturdy enough to support the weight of the mast + antenna.

    Option 2 would be to attach the mast to the fire escape railing outside one of my windows. The fire escape is of a fairly rudimentary style - just a ladder surrounded by a cage, not one of the (safer) stairway varieties. This option would be my first choice, but the closest window to the fire escape is also farthest from any interior power supply, so I’d have to run the coax cable quite a distance along the outside of the building to feed it through a different window where I can easily attach it to my RPi.

    So: has anyone successfully made an antenna mast that can:

    • attach to a window without drilling holes?
    • Attach to a brick facade without drilling holes?
    • Cleverly use gravity to “pin” the mast against the building?

    I've looked into using some kind of flag pole mounting solution, but so far it looks like I’ll have to Macgyver my way to a stable solution.

    Thanks for any help!

    Leave a comment:


  • 1090 MHz
    replied
    This is the one I use, Silicone Self-sealing Tape: https://www.homedepot.ca/en/home/p.t...00104039.html#
    It's in the electrical section.

    Leave a comment:


  • abcd567
    replied
    How-to Protect Outdoor Connectors and Cable From Ingress of Moisture (Due to Rain & Snow) and Resulting Short circuit, Corrosion, and Drop in Performance.

    The simplest way to protect your connectors and cable from ingress of moisture is to wrap self-amalgamating / self-fusing / self-bonding tape over the connectors. Please do NOT use ordinary electrical PVC tape as it wont protect properly, and soon deteriorate.

    An additional step in case of RG6 cable is to use Water Resistant type F-connectors which have built-in O-rings.

    Examples of applying self-fusing tape on antenna and coax connectors are given below:




    .
    .




    .

    .

    https://www.amazon.co.uk/gp/aw/s/ref...lgamating+tape
    .



    .

    .

    Last edited by abcd567; 2019-01-22, 04:13.

    Leave a comment:


  • Rooster
    replied
    Weather proofing makes ALL the difference, moisture is drawn into the coaxial cable like a sponge... even a night out with dew will draw in water - doesnt need to rain !!!
    Ive seen many a cable ruined this way, and theres no recovery... ALWAYS seal the end of the cable - beeswax, self amalgamating tape etc.
    Once moisture enters the cable the losses mount up exponentially...

    Leave a comment:


  • aesoprrp
    replied
    Originally posted by abcd567 View Post
    First you should try improving the antenna.
    After antenna improvement is done, then add an amplifier.
    Good advice, thanks! Just straightened out my radials, added 4 more to make it an 8-legged spider, and I'm already seeing an improvement. I'll post back with results after a few days.

    Leave a comment:


  • abcd567
    replied
    Originally posted by aesoprrp View Post
    1. For someone who's new to antenna design and theory, how important is it that I seal/weatherproof the connection between the center wire and the SO-239 core element? I've seen mention of sealing, weatherproofing, and enclosing these antennas, but how important is it really?
    It is not very essential. Lot of people use it without any sealing, weatherproofing, and enclosing.

    It works ok without sealing / water proofing. However after some period (say 1 to 3 years, depending on local weather conditions), rust & moisture set-in, and performance drops, or fails altogether.

    Applying water sealing increases the span of trouble free service.

    Originally posted by aesoprrp View Post
    2. Would a more accurate measurement and completely straight wires help the antenna perform much better, or is that a nominal difference?
    Depends how inaccurate it is initially. These antennas are very tolerant to dimensional errors, and will work OK even when built with an average skill. Making wire length, straightness of wires, and angle of bend more accurate may give an improvement of say 5% ~ 10% if it was originally build with an average skill.


    Originally posted by aesoprrp View Post
    3. Would soldering more wires on (say, 4 more to make it an 8-legged spider) make a big enough difference?
    It does make an appreciable difference, say 10% to 20%, but not a BIG difference.

    Originally posted by aesoprrp View Post
    4. Compared to those options above (improvements), would the better choice be to add an in-line amp?
    First you should try improving the antenna.
    After antenna improvement is done, then add an amplifier.
    Last edited by abcd567; 2019-01-19, 18:30.

    Leave a comment:


  • aesoprrp
    replied
    Delved into this thread a few weeks ago, and started out with a cantenna for my first DIY antenna build. Surprisingly good results! Got about 160nm range from my south-facing apartment window.

    So, naturally I want to see how far I can take this project, so I tracked down some SO-239 connectors, and this past week I soldered together a 4-legged spider antenna (see attached photo - no idea how to rotate it, sorry!). Measured roughly, bent the wires haphazardly, and mounted it in PVC piping with tape on the brick outside the window. Seeing about a 10% increase in data from this antenna over the cantenna. Pretty cool! I have a few questions for anyone who cares to chime in:


    1. For someone who's new to antenna design and theory, how important is it that I seal/weatherproof the connection between the center wire and the SO-239 core element? I've seen mention of sealing, weatherproofing, and enclosing these antennas, but how important is it really?

    2. Would a more accurate measurement and completely straight wires help the antenna perform much better, or is that a nominal difference?

    3. Would soldering more wires on (say, 4 more to make it an 8-legged spider) make a big enough difference?

    4. Compared to those options above (improvements), would the better choice be to add an in-line amp?

    My apartment is up pretty high, but the antenna can only see South, East, and West. Almost zero north coverage due to the building and the mountains directly to my north.

    Thanks for the help!
    Attached Files

    Leave a comment:


  • abcd567
    replied
    IMPEDANCE MATCHING STUB ADDED TO HORSESHOE ANTENNA

    Untested proposal. Expected to bring down SWR from 3.5 down to < 1.5

    Leave a comment:


  • abcd567
    replied
    SIMULATION OF HORSESHOE ANTENNA


    Gain = 3.2
    SWR = 3.5






    Leave a comment:

Working...
X