ad: ProAudio-1

MFJ-1835H Cobweb antenna review (high power version 1.5kW)

Discussion in 'Amateur Radio News' started by VA2PV, Jun 19, 2017.

ad: L-HROutlet
ad: l-rl
ad: Left-3
ad: abrind-2
ad: Left-2
ad: Radclub22-2
ad: L-MFJ
  1. VA2PV

    VA2PV XML Subscriber QRZ Page

    This video includes the unboxing, assembly, testing and review of the Cobweb MFJ-1835H antenna (H for the 1.5kW high power version). Too bad the condition of the bands were not good that day, I will make another video when we have better conditions.

    73 Pascal VA2PV

     

    Attached Files:

    W4AAX, K4MJF and NU4R like this.
  2. VA2PV

    VA2PV XML Subscriber QRZ Page

    I noticed after I posted the video online that at 7:31 my shack radio (TS-990) is in USB not in AM like the Elad QRP outside. The TS-990 would have read a better signal in AM but not much (2 to 3dB max, just tested on the same frequency), so the signals are still similar. Sorry, my mistake.
     
    W4AAX and NU4R like this.
  3. WC2Y

    WC2Y QRZ Lifetime Member #185 Platinum Subscriber Life Member QRZ Page

    ALWAYS ENJOY YOUR VIDEOS......IM GLAD YOU WERE ABLE TO TEST THE ANTENNA OUT, EVEN THOUGH CONDITIONS WERE HORRIBLE....I HAVE THIS ANTENNA ON MY LIST OF PURCHASES...GOOD LUCK WITH IT, AND MAY YOU HAVE MANY DX AND SUCCESS WITH THE ANTENNA...73, GIL K2YNY
     
    W4AAX and VA2PV like this.
  4. W6GMT

    W6GMT Ham Member QRZ Page

    Just bought one from DX Engineering Project for tomorrow is to unbox put together and get it up for field day. I will try for 25 feet. I will add comments after assembly
     
    W4AAX, NU4R and VA2PV like this.
  5. VA2PV

    VA2PV XML Subscriber QRZ Page

    True this antenna is perfect for field day. Don't tight the screws too much if you are dismantling it after, otherwise you can damage the wire (I did on the first band, 10M) and keep the wire bags as they are identified. 73 and have fun, hope the conditions will be better than now!
     
    NU4R likes this.
  6. NU4R

    NU4R XML Subscriber QRZ Page

    Thank you sir and 73!
     
    VA2PV likes this.
  7. NU4R

    NU4R XML Subscriber QRZ Page

    Be sure to keep us up-to-date Brock and how well it does @25 ft! 73 sir!
     
    W4AAX, K4MJF and VA2PV like this.
  8. KA4VNM

    KA4VNM Premium Subscriber QRZ Page

    Awesome video, excellent quality. Visiting your fine city this year sometime. What is your full time gig?

    Pat KA4VNM
     
    VA2PV likes this.
  9. VA2PV

    VA2PV XML Subscriber QRZ Page

    Thanks for the feedback. I work for a telecommunication company, I had no experience in video production when I started making ham radio videos in 2015. I discover a new hobby. I still makes a lot of mistakes, sometimes I able to correct it in post-production and sometimes I can't, hihi. All my videos are in 4k resolution, this represent a technical challenge, that's the whole purpose ;-) I made my first documentary in fall and posted online this winter, in 4K. Check it out and let me know what you think. By the way I’m located nearby Montreal. 73 Pascal VA2PV



    73
     
    K3SX likes this.
  10. BG3IQB

    BG3IQB Ham Member QRZ Page

    I do not have such a good condition to set up a large antenna system, only use MFJ-1788X, so very envious of you!
     
    W4AAX and VA2PV like this.
  11. KF5UMC

    KF5UMC Ham Member QRZ Page

    Well I watched/listened to the video...personally not sure what the antenna costs but the time involved to put the contraption together seems too much. I would be on the Air in a fraction of the time and many contacts later with the (Newtronics 50+ year old design) Hustler 7 band trap vertical. I can assembly the Hustler antenna in 10 minutes including mount on the back of my motor coach and coax into my rig and 1500 watts all day long 80/75, 40, 30, 20, 17, 15, 10m Also, I am very suspect of ANY antenna that tunes to 1:1.0...the impedance match with a unbalanced feedline is NEVER 50 ohms.

    73
    John KF5UMC/portable= living full- time in a 41ft motor coach.
     
    K3RW likes this.
  12. WA2LXB

    WA2LXB XML Subscriber QRZ Page

    Built one back in February with a friend on Long Island. Used a RigExpertA600 to analyze.

    Pros:
    -Simple to assemble
    -Worked 6 countries on 20, 17 and 15 first two hours on the air with Icom IC7300 barefoot. Didn't test 12 or 10.
    -Signal reports from Greenland, France, Guatemala, Louisiana, Malta, etc. all good.

    Cons:
    -Narrow banded but usable with a good autotuner on all bands...10M very narrow banded
    -Feedpoint box is a cheezy mount...single bolt, and it's easy to crack the fiberglass pole if you over torque the nut. Recommend adding zip ties to box to help to secure it.
    -SWR is very touchy to adjust with wire length. Simple things such as wrapping the spare wire tightly or loosely at the ends can greatly effect the peak SWR and the location of the lowest SWR point in the band.
    -SWR jumps around if the wind is blowing. There will inevitably be some slack in the antenna wire, and the vibration caused by the wind causes SWR to vary as the wires shake.
    -Fiberglass spreaders seem like they are too flimsy...time will tell.

    Once again...impressed with the contacts...not impressed with the difficulty in tuning each antenna length nor in the materials of construction.
     
    VA2PV, NF6E and K3RW like this.
  13. K3RW

    K3RW Ham Member QRZ Page

    I have the non-QRO version. I do not recommend it at.

    I replaced the 'screws' on mine with eyes so it maintains an even tension all around. I'm going to replace the wires with insulated flexwoven ones, since the bare galvanized 'silky' ones tend to unravel and fray on the ends, and a tree branch broke all of mine. Yep. It means more headache getting the wire lengths right since the VF of any improved wires could change the geometry of the antenna.

    I suspect a real 1:4 balun would serve better than the junky one it comes with. Maybe the higher wattage one is better, but I suspect mine isn't weatherproof.

    I really do not think MFJ has this 'tuning' part right. Essentially all it does is tension the wire, not change its electrical length. In my case I found no matter what I tried it was resonating out of band on 17. Buried in the instructions it says it is cut for the upper part of the band... which really does me no good when its already too short.

    The fiberglasd poles were good, but I'm basically rebuilding it as a donor skeleton. Very disappointed, albeit not surprised.

    Called MFJ tech support and had a couple of questions... the antenna shop wasn't helpful.

    YMMV, but I say, avoid. Dipoles are cheap and a 20-10 vertical works better anyways. This is an omni antenna not worth the hassle.
     
  14. K0PIR

    K0PIR Ham Member QRZ Page

    Exceptional! Nice video Pascal, but like some others, I don't think I would like setting this up on FD. In windy South Dakota conditions it would be a mess hi hi.
    Take care, keep up the good work. Seeing your videos is about as close as I get to some of this equipment. :)
     
    VA2PV likes this.
  15. KA4VNM

    KA4VNM Premium Subscriber QRZ Page

    The Mosley is actually a small loaded 3 element but does a great job and is light. I also have an end fed 130 foot wire and a dedicated 40 meter OCFD. My dads family is from Collingwood in ON and have friends in Brockville. Flying in to Montreal spending a few days then driving to Quebec City and up to Mont Blanc for a day trip. Wife won't fly over night to Europe so this sort of a trip for her. As close to Europe as she will get. My French is classical so will have listen hard to untangle the Quebecois french. Avoir mon amie.

    Pat
     
    K0PIR likes this.

Share This Page

ad: AbAuRe-1