Antenna Optimization?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KC3IYV, Aug 28, 2021.

ad: L-HROutlet
ad: l-rl
ad: L-MFJ
ad: Left-2
ad: HRDLLC-2
ad: abrind-2
ad: L-Geochron
ad: Left-3
ad: MessiPaoloni-1
  1. KC3IYV

    KC3IYV Premium Subscriber QRZ Page

    Hey guys! This is the first time posting to the forum!

    I come here as a relatively new ham with a very very basic knowledge of all the science. Having been generally self taught to pass my exams through books and internet info, I'm starting to really second guess some of my knowledge specifically regarding antenna placement efficacy and optimization. Moreover, I think it might be good to get some advice before I start doing anything too dramatic with climbing around my house and putting up anything permanent.

    I run a 100w Yaesu FT-450d with a multiband endfed that I've tried a few different ways. Always had great SWR but I'm starting to think that it's not only about SWR.

    I've never been able to do much on Phone beyond 2m FM. All my work for DX has been on FT8. Given this space limitation and current solar cycle, is there anyway I can make the best of a not so optimal situation? Is there any antenna config/placement here that'll give me a fighting chance to DX on phone? Most importantly, how wrong am I doing this?

    Would love you guys to take a look at some photos of my setup and see what you think. You'll see from the pictures there's a lot of factors and safety considerations I have to deal with given this space:

    1. Overhead powerlines and Utilities (propane tank, heating oil tank.)
    2. Relatively tight space between two houses. (I'm the gray house)
    3. The sudden appearance of my neighbors RV
    4. My wife (not pictured.... )

    At the moment I've got an endfed antenna wrapped around PVC and erected in a vertical position. It receives pretty well but tx isn't any better or worse than other antennas or positions. This particular antenna I've tried as a sloper as well. The main trouble is that I want something that isn't taking up a lot of room and doesn't requirea lot of acrobatic feats for install. I def want to get more height and work towards a rooftop install, but I don't want to risk accident for something that isn't ideal. In other words, trial and error on something like this makes me a little uneasy. So getting some second opinions on this would be a HUGE help!

    THANKS!!!

    DJ - KC3IYV


    IMG_1794.JPG


    IMG_1795.JPG IMG_1796.JPG IMG_1797.JPG
    IMG_1798.JPG IMG_1799.JPG fccc IMG_1799.JPG
     
  2. WA7ARK

    WA7ARK Ham Member QRZ Page

    Can you utilize the tree on the lake side of your house?

    You will make more SSB contacts, especially on 40m with a wire that is mostly horizontal, and as high as you can get it, ideally at least 35ft. An EFHW designed for 40m to 10m, fed from the house top, running toward that tree might be your best bet.

    FT8 has about a 25db advantage over SSB, so it is not surprising that you need a better antenna.

    I just had a SSB QSO from Alberta to CA,AZ and UT on 40m about an hour ago. I use a ZS6BKW multi-band dipole antenna (in the shape of an inverted-V) from here at our Summer house. My friends are using a variety of antennas. The guy using a vertical (from AZ) had the worst signal. The others are using horizontal wires.
     
    Last edited: Aug 28, 2021
  3. W9IQ

    W9IQ Ham Member QRZ Page

    The low position of the antenna doesn't help at all. Helically wound antennas tend to be very inefficient as well.

    It looks like a dipole strung between the peak of your roof over your garage to one of the trees in your back yard may be an option. That orientation would do well for Europe and Asia contacts. You would risk some RFI pickup from your house but it you are not having that problem with your current antenna, that may not be much of an issue. Use a good common mode choke at the feedpoint of the dipole and one before the coax enters your house. That will help keep household RFI out of your antenna/receiver and keep your transmit power out of the house.

    - Glenn W9IQ
     
  4. KC3IYV

    KC3IYV Premium Subscriber QRZ Page

    Sadly the tree isn’t ours. I fear I’ll need to stretch out a wire across the top of the roof. We have a very long house (90ft). Can I lay the antenna on the shingles?
     
  5. W4HWD

    W4HWD Premium Subscriber QRZ Page

    A dipole that low, amongst all those obstacles is going to have a dipole pattern, thus "favoring" certain directions?

    I have a doublet with a flat-top (actual dipole, not inverted-vee) that's 57' above the house and oriented like a runway 040-220 degrees; that puts Europe off the northeast end of the wire and I work Europe all the time; ditto my other doublet oriented 080-260 degrees at 48 feet.

    This broadside pattern dipole stuff only applies in more ideal situations; in most installations the ends aren't really "down" from the sides, making most dipoles (and just about all inverted-vee's) omnidirectional antennas. In other words, most hams can't get dipoles high enough up in the clear to realize true dipole patterns, so dipole "orientation" doesn't matter most of the time; and the closer it is to the ground relative to frequency (particularly the ends) the more omnidirectional it becomes.
     
    Last edited: Aug 28, 2021
  6. K1LKP

    K1LKP Platinum Subscriber Platinum Subscriber QRZ Page

    HELLO DJ,

    GREAT FIRST POST AND SUPER PICTURES.

    IS ANY OF THE LAKE FRONT PROPERTY YOURS
    OR DOES UR PROPERTY LINE END AT THE
    FENCE ???

    73 ES WELCOME TO THE FUN FILLED WORLD
    OF THE QRZ FORUMS.

    K1LKP
     
  7. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    The pictures all seem to be "one side" of the house.

    What's the other side like? What's the back side facing the river like?
     
  8. KK4OBI

    KK4OBI Ham Member QRZ Page

    Oh boy! Do you have potential! I look at the fence at the dock and think maybe it would support a 35 t0 40 foot push-up pole with a marine grade block on top. The block would give an easy way to lower the antenna before storms and be just the right height for DX on 20 meters. It would be away from the electronic noise of you house. With the Chesapeake Bay at the shore the water table provides a terrific ground. The Bay is only brackish that far North so not much help from sea water.

    I look at the moderate pitch of your roof and think it would be no problem to go up there to mount a pole with a block at the peak on the back of the house. This would make it the same height as the pole at the dock and antenna easy up, easy down.

    As for what antenna to use, you research that. Listen to the experts like WA7ARK. Just having good height over water with easy up-down will catapult you into learning about and effectively using HF antennas.
     
    Last edited: Aug 28, 2021
  9. KC3IYV

    KC3IYV Premium Subscriber QRZ Page

    We have all the river frontage - you go down some stairs and we have a pier. setting up any antenna at sea level would kinda go against the idea of getting your antenna up high?
     
  10. K7GQ

    K7GQ Subscriber QRZ Page

    You have a sweet QTH there! Though I'm generally not much of a fan of vertical antennas, I'd put a 4BTV/5BTV in your back yard with as many radials of various lengths as you could do buried in the lawn. That would be quite an improvement over your current situation.
     
    WA9FZB and WB5YUZ like this.

Share This Page