Tuesday, August 6, 2019

N6BT V8 Vertical Dipole Installation

I just installed an N6BT.com V8 vertical antenna in my backyard. I had not settled on a home antenna since Hurricane Michael took my trees and the storage building. Unfortunately, I still have high voltage power lines across the back of the lot. I am not in an HOA neighborhood. A tower and a beam would be effective but that would be a significant investment.

N6BT V8 installed in the backyard.
 I have had good experience with N6BT antennas. I use the N6BT Bravo 7K when activating parks. It is a remarkable performer on the saltwater shore. However, it has also done the job over the ground in the parks. The N6BT vertical antennas evolve. Instead of using coils and adjusting element lengths like the Bravo 7K, The V8 uses a remote tuner, in this case, the MFJ 993BRT. Tom Schiller N6BT calls this antenna a vertical dipole. The ancestor to this antenna was a vertical dipole with a horizontal section at both ends for capacitive loading. As Tom says, the top element was extended, and the top flat section was removed. On the lower element, it was shortened and extended horizontally. So there you have it. This is very asymmetric vertical dipole indeed. The good news is that the antenna is complete and does not require ground radials.

Please watch my YouTube video that covers the details of the installation. The biggest issue was the tuner, which is from MFJ. The one I received was DOA. It did not do anything. I supplied the 12-volt power via a bias T on the transmitter end of the coax. Yet, I did not hear any relay clicks when RF was applied, so tuning never started. I did get lucky after removing the cover, there were some switches hidden under a circuit board. This board would be for the desktop version of this tuner. One of the switches is labeled power. I pushed that switch, and the relays clicked when 12 volts was applied. I left it like that and put the cover back on, and now the tuner works as intended.

The MFJ 993BRT remote tuner mounted.
Initially, the antenna did not tune on 40 CW. After playing around with the hairpin coil, it finds a match on 40 CW. So it tunes quickly from 60 meters and up. On 80 meters the tuner struggles. It will quit trying after a while. Strangely if a reapply RF, the SWR is good. In any case, 80 meters will be the exception for my operating. Since I now have a remote tuner in the middle of the yard, I could experiment with some wires to make a doublet or maybe turn the V8 into an inverted L for the low bands. I do have a tree on each side fence line to run a wire to. I think I will find out what the stock antenna will do first.

The hair-pin coil
I have consistent noise from those powerlines. It sounds like arcing, and I should call the power company. Short of that, I have a W6LVP broadband loop mounted on a short post with a rotator in the front of the house. This antenna is much quieter, and I can null the noise to some degree. Therefore the V8 is mainly a transmit antenna. I am delighted with the W6LVP loop.

The antenna slips into a PVC pipe buried 18 inches.
I have had several rag-chew QSOs on 40 CW for a start. If the solar cycle gets cranking, I will be ready for the high bands. I am a little nervous about lightening. However, I can lift off the vertical section of the antenna and lay it on the ground. Then the antenna is much less of a target.

The N6BT Bravo 7K predecessor to the V8
The bottom line, I am going to enjoy this antenna. I can now get on the HF bands from the house. Thanks to Tom N6BT for an antenna solution that works for my situation. This antenna is available exclusively from Ham Radio Outlet. The tuner is a separate purchase.