Once the Hustler 4BTV was up it was time to see if laying the radials, burying the coax and putting the antenna mount in concrete was all worth it. The SWR checks are next, kinda the "where the rubber meets the road" In the Hustler manual as well as the DX Engineering manual basic setup measurements are given to get you started with the antenna. In the DX Engineering manual, you are informed that these measurements are based on a no radial setup. For this reason, don't be alarmed at the resonant frequency most likely will be where you don't want it.
This is not an issue as you can adjust the traps to remedy this situation. The Hustler manual informs owners that trap adjustment voids the warranty with Hustler, BUT if you purchase your Hustler vertical from DX Engineering they will still honour the warranty. I purchased my antenna in Canada and I decided to adjust the traps and take my chances. I did read the manual very carefully regarding trap adjustment and it's no big deal to do.
One BIG advantage in regards to checking and adjusting the SWR is to have an antenna analyzer. It will save you time and frustration. I have the MFJ 259B an older unit but it works great, it does not give me a sweep graphical view but I can easily plot the SWR by checking the SWR at certain frequencies. I do have the Funk Amateur FA-VA4 but for the life of me I just can't figure out how to work it.
With the antenna analyzer connected I was pleased with the rough results, below are the rough readings:
28.000 1.1 to 28.900 SWR 1.2
For this reason, 10m was not touched.
21.897 SWR 2.0
21.426 SWR 1:3
21.116 SWR 2.0
From the above SWR numbers, the 15m trap has to be lengthened.
13.711 SWR 2.0
13.997 SWR 1.3
14.222 SWR 2.0
From the above SWR, the 20m trap also has to be lengthened. Before this is done the manual advises that first double check the 20m SWR after adjusting the 15m trap.
6.982 SWR 2.0
7.050 SWR 1.8
7.168 SWR 2.0
With the 4BTV there is no 40m trap to adjust but I can in this case make the final section of the antenna longer. Again I have to recheck this SWR when the 15m trap is adjusted and if the 20m trap still needs adjusting I have to check 40m again before any section adjustment is made.
Before any adjustments are made to any trap it is advised to mark on the tubing the factor position of the trap just in case you have to start all over again. With each of the 3 traps marked to the factor position, I proceeded to adjust the 15meter trap and make it longer. Longer meaning between 1/16 to 1/8 longer (or shorter if needed) I had to make 2 adjustments to the 15m trap to get my desired results. I mainly use CW and and now and again FT8, therefore I wanted my best SWR results between 21.000-21.100.
Below is the final results.
21.060 SWR 1.3
21.100 SWR 1.4
I then looked at 10 meters and it had not changed at all.
28.000 1.1 SWR
28.150 1.1 SWR
28.190 1.1 SWR
I then checked the 20m section of the band with the antenna analyzer and was very pleased to see that now no trap adjustment was needed. Below are the final results for 20 meters.
14.000 SWR 1.1
14.030 SWR 1.3
14.100 SWR 1.4
I was not as fortunate with 40 meters the new SWR after adjusting the 15m trap was:
6.976 SWR 2.0
7.013 SWR 1.8
7.219 SWR 2.0
The final section of the mast has to be made longer and one of my concerns was, is this going to mess around with the 10,15 and 20m SWR? I did not have too much extra length to play with in the final section. I ended up stopping when I had about 1.5 inches of tubing inside the lower mast section. I did not want to take any more out. Below are my final results for 40 meters.
7.000 SWR 2.0
7.025 SWR 1.9
7.073 SWR 1.8
7.106 SWR 1.9
After the final 40m mast adjustment I was pleased to see the SWR for 10,15 and 20m was unchanged. Now 40m is not the best result but the Icom 7610 tuner handles the SWR without issues. My property is small and the longest radial I could put out was 20 feet. I could have put out some longer ones but it would have zig-zagged all over the place. There are a total of 30 radials and about 8 are 20 feet.
Coming up in the next post...how does the Hustler 4 BTV stack up against the EndFed antenna?