Moonraker SkyScan 11-533

[etuck]

Does anyone have any experience with this antenna set?
I'm in foothills of nc/ga areas and trying to get better communication mainly in cherokee county 28906 area. I have a Uniden sds200 and would like to be able to move to different places in my home and garage. Both places have metal roofs. Your recommendations is appreciated. Thanks

Moonraker UK Limited 11-533 Moonraker Ltd SkyScan VHF/UHF Receive Antennas | DX Engineering

Free Shipping - Moonraker Ltd SkyScan VHF/UHF Receive Antennas with qualifying orders of $99. Shop VHF/UHF Mobile Monitor Antennas at DX Engineering.

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[etuck]

Tried this 11-533 antenna out, set on my garage metal roof. Noticed some improved coverage in lower bands but still having trouble within the 140-160 MGz. What can I do to target this range? Thanks!

 

[Ubbe]

Try and remove those 6 horisontal elements and all top verticals except the longest one to make it a GP antenna. That should improve VHF. You can then also try a top vertical without a coil that are 50cm long that will be tuned to 150MHz, if you manage to fit it on that base.

/Ubbe

 

[etuck]

Try and remove those 6 horisontal elements and all top verticals except the longest one to make it a GP antenna. That should improve VHF. You can then also try a top vertical without a coil that are 50cm long that will be tuned to 150MHz, if you manage to fit it on that base.

/Ubbe

It only has 4 horizontal elements, and the Longest vertical is 22.5 in /
57.15 cm, and has no coil.

 

[prcguy]

The Moonraker model you have is kind of a circus on wheels and I suspect designed more to look more useful than it actually is. What bands are you interested in most? If its just VHF/UHF then a dual band VHF/UHF mobile whip with wide bandwidth and a little gain on a ground plane mount should easily outperform the Moonraker thing. Maybe a Comet CA-2X4SR and a Larsen style ground plane NMO with four radials. To do any better than that would require a much larger dual band base antenna.

I've run a number of small multiband mag mount and NMO ground plane type antennas in my garage and when I stick on a larger Comet CA-2X4SR or Larsen NMO 2/70B the signals go up noticeably, although the Larsen is tuned for only the amateur bands.

 

[Ubbe]

It only has 4 horizontal elements, and the Longest vertical is 22.5 in /
57.15 cm, and has no coil.

OK, then it's cut for 130MHz, probably in an attempt to cover VHF-AIR as well as VHF-HI. It probably has a threaded end that screws into the base. You can buy threaded steel rods, could that be a metric M3, and cut that to 50cm. Or buy a thinner threaded steel rod and secure with nuts on both sides of the base, if the hole goes all they way through. Remove those 4 horisontal pieces as those just makes things worse for VHF, and also remove all other verticals.

To test performance you can use 50cm of stiff electrical wire, or perhaps straighten out a metal wire coat hanger, and set in the old hole and secure with a match stick or paperclip to make it have electrical contact.

If that works then try adding the old vertical stuff one by one to increase performance of other frequency bands and check that VHF isn't affected too much. But those 4 horisontal elements are useless as they are intended for a discone operation but that are ruined by the vertical elements that are not isolated by impedance coils and interacts between each other in a negative way as they are out of phase with the horisontals and cancel out each other.

A proper way to use that antenna could be to remove all verticals and only leave the one with the coil. I don't know what that coiled vertical are tuned to, perhaps UHF 400MHz, then you'll have UHF as a GP and the discone works for 700MHz and up. Or remove those 4 horisontal elements and use all verticals as a compromised multiband GP antenna for 500MHz and lower, but it will still receive 700MHz and up and not be totally dead. But that's for general use and will not improve your VHF 150MHz performance.

/Ubbe

 

[etuck]

The Moonraker model you have is kind of a circus on wheels and I suspect designed more to look more useful than it actually is. What bands are you interested in most? If its just VHF/UHF then a dual band VHF/UHF mobile whip with wide bandwidth and a little gain on a ground plane mount should easily outperform the Moonraker thing. Maybe a Comet CA-2X4SR and a Larsen style ground plane NMO with four radials. To do any better than that would require a much larger dual band base antenna.

I've run a number of small multiband mag mount and NMO ground plane type antennas in my garage and when I stick on a larger Comet CA-2X4SR or Larsen NMO 2/70B the signals go up noticeably, although the Larsen is tuned for only the amateur bands.

The Moonraker model you have is kind of a circus on wheels and I suspect designed more to look more useful than it actually is. What bands are you interested in most? If its just VHF/UHF then a dual band VHF/UHF mobile whip with wide bandwidth and a little gain on a ground plane mount should easily outperform the Moonraker thing. Maybe a Comet CA-2X4SR and a Larsen style ground plane NMO with four radials. To do any better than that would require a much larger dual band base antenna.

I've run a number of small multiband mag mount and NMO ground plane type antennas in my garage and when I stick on a larger Comet CA-2X4SR or Larsen NMO 2/70B the signals go up noticeably, although the Larsen is tuned for only the amateur bands.

I'm new at all this ( as a hobby ). I Was hoping to get as much as I can out of my SDS200, but as stated, and would like to have a mobile antenna a setup to move from house to garage areas, both with metal roofs. I'm getting great NC State Patrol, (Viper I assume ) but only partial local 140 - 160 communication. I purchased the 11-533 hoping to gain this coverage, although not working much better, if any, than the stock antenna. If too many issues with mobile, I may just try a Omni X as a few others have suggested, although would have to mount only on a mast I assume. If that's the best option I'll go that route. ???

 

[Ubbe]

I may just try a Omni X as a few others have suggested, although would have to mount only on a mast I assume. If that's the best option I'll go that route. ???

Omni-X are three dipoles connected in parallel and will interact between each other and the two VHF dipoles are tilted to point up in the sky and down in ground and are between vertical and horizontal polarisations, I.E. a compromise. You could try to use two 50cm lengths of electrical wire, one connected to the center lead of a coax and pointing straight up and the other to the shield hanging straight down. Tape that to a broom handle or other non conducting material and place in a window. It will probably receive enough at UHF and 800MHz band to work satisfactory.

/Ubbe