Description:

This is a comparison between the three different JBX antennas recently tested. Results are based on 36" spacing between stacked antennas. Results and comments below.

Conclusion:

• The shape of the waveforms are very similar, the main difference being gain. The level of gain can be seen in the height of the signal waveform, the large graduation lines represent 10dB. The JBX14WB has similar gain to the JBX08WB on the lower channels, the upper channels show a increase in gain on the JBX14WB. The JBX21WB has higher gain than both on all channels.
• As you can see, the difference in measured gain between the JBX21WB and the JBX14WB is only 2-3dB. This proves how important it is not to lose gain due to poor quality coax cable or loose connections. With RG-11 cable at 100', you can save an extra 2dB of noise free gain compared to RG-6 cable that would have otherwise been lost in the cable.
• I found the multipath reduction from stacking to be about the same on all three antennas. Antenna selection should be based on your location and potential strength of signal, see below for my recommendations on antenna selection.
• The JBX08WB stacked should work well in areas where signal gain is high (line of site at 15-30 miles), but severe multipath is preventing reliable reception. If surrounding building are the cause of multipath, this setup should work well.
• The JBX14WB stacked should work well in areas where signal gain is average (line of site at 30-60 miles), but severe multipath is preventing reliable reception. If line of site is being blocked by small rolling hills in the distance causing multipath or long line of sight distances are involved, this antenna should provide a good signal.
• The JBX21WB stacked should work well in areas where signal gain is very low and no line of sight with transmitters. It will also work well for picking up very distant weak signals. If a large mountain range is in your signal path or you are trying to get signals from over 60 miles away, this antenna setup is going to be your best bet.

Quad Stacked?

Well, I did not have four identical antennas, so I decided to try a quad using two 14's and two 08's. I just connected all four antennas to a 4-way splitter with equal length coax and it worked great! I would say it is just about equal to two JBX21WB's. This is not really a practical setup though, since the cost and weight are more than using two 21's, but since I had these antennas laying around, I just had to give it a try. It would be a option for someone looking to put something powerful in a attic. The turning radius for stacked JBX14WB's is 48". You could do a quad stack with the 08's and get the turning radius down to 36". Certainly worth thinking about to get around the "wife acceptance factor" compared to a roof antenna.