DTV Receive Antenna Height Comparison

[WHJ]

Around a year ago I added a second Winegard HD7698P DTV receive antenna at a higher level on a different tower. Since then, I have slightly changed their heights and added to the antennas around them. The preamps used with them have changed as well. I most always have them pointed in different directions. With the Es and prime tropo seasons over I decided finally to begin a more formal receive comparison.

The two HD7698P's are mounted at 63 and 85 feed above ground level. The lower one has a home built 14 dB preamplifier using a TQP3M9028 IC while the higher one has a 17 dB preamplifier using a MAAMSS IC. Both preamps are mounted near the antenna. The higher one has greater gain due to the larger loss in its longer feedline.

The reception difference is shown in the attachment for three low power TV stations. I chose those expecting mostly ground wave receptions with less tropo influence.

As you would expect the reception was better on the higher antenna. You can also see the effects of a higher transmit antenna. K33AC was received better due to its 49% higher transmit antenna than KWBE ever though KWBE had 76% higher power at 78% of K33AC's distance.

For tropo DX either antenna might be better due to many of the elevation lobes on the lower antenna being near the elevation nulls for the higher antenna. This is true for both UHF and high band VHF reception.

[K4LY]

Interesting comparisons WHJ. For FM, my 14 el InnoVantenna is on the chimney at 24' and my Stellar is at 72' on my tower. The more directive, higher gain InnoV on the chimney has been better for both tropo and Es. I have seeral VHF and UHF antennas on my roof and on my two 66' towers. Before the repack, the higher VHF antennas were better for both tropo and Es. The higher antennas were better on UHF. Now, post repack I think very directional antennas will work best on the crowded band, and in my case, on a hilltop, maybe a lower antenna will receie less co-channel interference. As for dB comparisons between varous antennas and preamps on a specific channel, it's possible to isolate and calculate the many variables except for ground gain which changes at every height, and in every different direction, and for every different station! I do lots of A/B testing, but think it tells me as much about the path, ground gain, and multipath as about the hardware.

[WHJ]

I just summarized my antennas used this year at https://forums.wtfda.org/forum/dx-eq...nnas-equipment

When conditions are enhanced the antenna choice and height are less important. Lower antennas can even be better for some paths. But when conditions are minimal and for most longer distance reception, higher is generally better...