43 Foot Vertical and 10 80 OCF Dipole

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KI5KEE, Feb 24, 2021.

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  1. KI5KEE

    KI5KEE Premium Subscriber QRZ Page

    I am a fairly new ham and have limited room to put up Antenna's

    I currently have a Yaesu DX 3000, ATR-30 tuner, AL80B amp with two HF antenna's used to transmit.

    These two antenna's are a Buckmaster 3kw 10-80 OCF at 30 feet on vertex and 10 feet on the ends in an inverted V configuration

    I also have a zero five 43 foot vertical with 30 radials of various lengths. Close to 800 feet of wire for the radials. I am using the standard UnNun supplied with the antenna.

    I use two receive W6LVP loops with a NCC 2 for receiving.

    I am in particular interested in 80 meters and the performance of both of these antennas

    What I have noticed is the 43 foot vertical outperforms the dipole. This is by observation in using the Northern Utah Websdr site to do comparisons and by feedback from other ham radio operators.

    The vertical gets good signal reports from other operators all over the country. I am able to do DX very well getting 5 -9 reports consistantly on 80 meters and other bands

    Both antennas are tuned using the ATR-30 tuner. I have never had any issues with SWR "creeping" or raising during the use of these antennas.. I typically run between 800 and 1000 watts on 80 meters

    On the 43 foot vertical the untuned SWR is around 7 to 7.5 untuned. The dipole is 1.5 to 2.1 untuned.

    I am able to tune the 43 foot vertical on 160 m and can run around 400 watts through it. I have made several contacts. I know this is not a best case to use on 160 meters. But the ATR 30 will tune the antenna on

    I was looking at the MFJ 2910 unit to add base loading to the 80 and 160 meter bands in order to allow a greater tuning bandwidth. Currently the tuning bandwidth is very narrow as everyone knows.

    Also I am looking at the MFJ 2910 to allow a better untuned SWR.

    I really do not want to add a remote antenna tuner since I have the ATR-30 and a MFJ 998 that I can use.

    I run about 90 feet of LMR400 with a My Antenna's Common Mode Choke.

    So given this back ground does anyone have any comments on the MFJ 2910? Am I better off just keeping what I have? Is there other options?

    My main concern is how much power the MFJ 2910 will handle. It is rated for 1.5wk PEP and 750 watts CW.

    Or should I just bite the bullet and get a remote tuner?

    Thanks in advance for any feedback
     
    AK5B likes this.
  2. K0UO

    K0UO Platinum Subscriber Platinum Subscriber QRZ Page

    I would highly recommend a remote outside tuner on the 43ft.
    But you can use your other tuners use high quality feed line to take the losses and SWR lmr 400 is great for this on HF..
    Congratulations you've accomplished a whole lot/ as a new amateur. A great job/ but Don't Take the Off Center fed down they'll be times it will work better.
    I hope to be able to work you sometime on the air. Antennas are the most important thing for a good amateur station and you're working on that/ it's always good to have multiple sntennas it's also great that you're experimenting that's what amateur radio is all about, there will be some good ideas post it for you here on QRZ
     
    Last edited: Feb 24, 2021
    M0AGP, KU3X and AK5B like this.
  3. AK5B

    AK5B Ham Member QRZ Page

    If you want a top quality automatic remote tuner, this is probably one of the very best on the market:

    https://www.eham.net/reviews/view-product?id=11853

    (While the reviews above are for the JC-4 the slightly revised current model is the JC-4S and runs about $670 with the shipping from Holland)

    I was about to purchase an LDG RT600 but after reading and comparing all the reviews I felt better about spending more to get the best.

    Hope this helps!

    73,

    Jeff
     
  4. KH6AQ

    KH6AQ Ham Member QRZ Page

    Not counting antenna tuner loss (which will further decrease the non-MFJ-2910 gain) the MFJ-2910 improves the 3.5MHz performance by ~1dB and the 1.8MHz performance by ~5dB. This simulation does not exactly model your installation and is intended only to get an idea of what the improvement may be.

    I believe the MFJ-2910 has less loss than a remote antenna tuner. How much I don't know.


    EZNEC, antenna as it presently is configured:
    3.5MHz
    43' vertical
    0.005/13 GND
    4 x 32' radials
    10 ohm loss placed in the vertical
    90' LMR-400 coax, VF = 0.85, loss = 0.20dB matched
    Coax loss = 1.7dB

    1.8MHz

    Coax loss = 5.6dB

    EZNEC, added MFJ-2910 to resonate and match the antenna
    Inductor Q = 300.
    3.5MHz improvement, 0.9dB
    1.8MHz improvement, 4.5dB


    MFJ-2910 https://www.dxengineering.com/parts/mfj-2910
    Instructions https://static.dxengineering.com/global/images/instructions/mfj-2910.pdf
     
  5. WB5YUZ

    WB5YUZ Ham Member QRZ Page

    I don't have any advice about the tuner, but...

    Get the ends of the OCF higher off the ground. You can build two little 20 ft. masts out of cheap top rail from a big-box store and guy them off with dacron rope. A weekend project that will cut back considerably on your ground losses. (Sometimes, when you cut losses, SWR will go up a little. But remember that SWR is only one indicator of antenna performance and don't be too concerned, especially if you are using a tuner.)

    But I wouldn't try to go much higher than that with cheap top rail.
     
  6. KI5KEE

    KI5KEE Premium Subscriber QRZ Page

    Thanks for all the replies. Has anyone used the MFJ 2910. Any reviews?
     
  7. AK5B

    AK5B Ham Member QRZ Page

    I just searched eham's reviews and none so far that I could find; I would be curious to see any, too.

    73,

    Jeff
     
  8. KR2C

    KR2C Platinum Subscriber Platinum Subscriber QRZ Page

    Man, I use an MRJ remote tuner on my 43' vertical and even though it tunes, it almost useless on 80m. A low dipole outperforms it consistantly.
     
  9. WA7ARK

    WA7ARK Ham Member QRZ Page

    Smart ass comment deleted...
     
  10. KR2C

    KR2C Platinum Subscriber Platinum Subscriber QRZ Page

    Yea, I get that. I only remark because the OP states the opposite at his shack.
     

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