ad: elecraft

New Antenna Mast on an old C-Band Antenna?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KG5NNA, Nov 17, 2016.

ad: L-HROutlet
ad: l-rl
ad: L-Geochron
ad: abrind-2
ad: Left-2
ad: HRDLLC-2
ad: L-MFJ
ad: MessiPaoloni-1
ad: Left-3
  1. KG5NNA

    KG5NNA Ham Member QRZ Page

    Greetings!

    I need a little advice to see if my plan will be ok.

    I recently got my licenses for both General and Tech, and have purchased a Yaesu FT-991 along with a 40-foot telescoping, galvanized mast. I have a hand-me-down UHF/VHF antenna and bought an Alpha-Delta multiband sloper for my HF.

    I'm a little up in years, over 60, but not yet to retirement, so my days of climbing around nimbly on ladders and rooftops are very close to being behind me. When my wife and I moved into our home in a suburban neighborhood in 1985, the only "cable TV" available was via a C-Band antenna that rotated. So, there is a mast in our side yard about 5-6" in diameter, in concrete deep in the ground, and at the top is a big ol' C-Band antenna dish. Now the whole thing has been completely inoperable for many years so basically it's really a hunk of metal sitting on a pole.

    What I think would be a good, easy solution for me, would be to bolt in some manner, my new galvanized 40' mast to the pole of that C-Band antenna using some clamps. I would attach the 2m/70cm antenna on the ground, mount the Alpha-Delta and just raise the thing up flush against that pole. then find me some reasonably heavy duty clamps or other hardware to secure it. I might not be able to get up to the 40', but I could put guy wires on it from the top and tie those off to ground augers.

    My biggest question is whether either antenna is going to be drastically affected by the big C-band dish that's just sitting there. The 2m/70cm theoretically should have an antenna field that's a figure-8 I believe and if I orient that antenna where the figure-8 isn't pointing toward the dish, I think that will be OK. The HF sloper antenna, however may need away from the pole, too. I dont have any trees on the property sans a crêpe myrtle that is roof high, and could be used if i can find a place to tie it off.

    Is this a good plan? Getting that dish down would be expensive as I'd have to hire someone with a cherry picker of some sort to come and remove it, so I'm hoping it won't interfere.

    Thank you in advance for your thoughts!

    73,
    Korky Kathman
    Coppell, TX
    KG5NNA
     
  2. KA9JLM

    KA9JLM Ham Member QRZ Page

    If you are not using the dish, Someone that uses C-Band may take it down for free.

    Good Luck.
     
  3. K9STH

    K9STH Ham Member QRZ Page

    Several things:

    First of all, you don't have licenses for both Technician Class and General Class! The General Class license replaces the Technician Class license and, as such, you only have a single license. The General Class license has all of the privileges of the Technician Class license and a LOT more privileges on HF and MF (the 160-meter band is MF).

    Next, a sloper antenna is not going to have a "figure 8" pattern especially on the lower frequency bands even without the old dish antenna coming into play. The actual pattern will be, primarily, omni-directional (works over the full 360-degrees of the compass) but it will, probably, not be a true circle. That is, there will be a slightly better signal in some directions when compared with other directions.

    What is the VHF / UHF antenna? If a vertical, it is going to have, basically, an omni-directional pattern and, again, not a "figure 8". There are vertically polarized antennas that do have a "figure 8" pattern. However, they are certainly NOT common!

    The "dish" may, or may not, have some effect on the sloper and that will not be easy to predict. Basically, if you don't want to remove the dish, then you are just going to have to install the antennas and see what happens. I expect that the effect of the dish will be minimal and that you won't be able to tell that it is even there. The dish won't have any effect on the VHF / UHF antenna mounted on the top of the mast.

    According to the map, here on QRZ.com, I am 15.3-miles almost exactly east of you over in the Collin County portion of Richardson.

    Glen, K9STH
     
    AK5B likes this.

Share This Page