December 10, 2011

Portable Rotatable Dipole

For our portable operations, we have been using a portable rotatable HF dipole from EmComm-Products (model RADS 9-11/A) since 2008.  This antenna is rated for up to 200W UHF/VHF / 250W PEP HF.  In our setup we run no more than 50W on UHF/VHF and 100W on HF.

One particularly useful feature of the antenna is that it provides HF and a second VHF/UHF antenna on top of the dipole which is fed by a separate cable.  This allows the operator to run both a HF radio and VHF/UHF radio concurrently on one mast.

The mast is sectional fiberglass, guyed, and goes up very easily with two people (takes about 15 minutes).  The Velcro cable ties used to neatly store the cable double as ties between the mast and cable.

To rotate the antenna we simply give the mast a twist.  This is usually enough to cause the dipole to turn in the in the desired direction.  We have also used a light line tied to one end of the dipole to guide the rotation.
Dipole that can be rotated manually
NJ2X's Rotatable HF Dipole Antenna on the beach in Hattaras Island, NC

The dipole sections can be changed out and manually "tuned" for all HF bands from 160m to 10m and also VHF on 6m.  Tuning is accomplished by adjusting the telescopic sections.  A roll up tape measure and guidebook in the bag helps with the adjustment for specific bands and frequencies.

The entire antenna system packs up neatly into a heavy duty military green water resistant bag.  This makes it our preferred field day antenna.  We have also used it for mini-DX expeditions.  Pictured above is the antenna setup overlooking the beach on Hatteras Island, NC.

Emergency communication rotatable dipole antenna packed up in its go-bag

This antenna system has been a real pleasure to use and we look forward to breaking it out again for Field Day 2012.  Now only to decide where we will take it...



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© Michael W. Maher and NJ2X.COM, 2012. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Michael W. Maher and NJ2X.COM with appropriate and specific direction to the original content.