When I retired last June I moved to the Highlands of Arizona, a community known as Prescott (pronounced "preskit" rhymes with "biscuit"), grid square DM34un. I was excited to start over again on 2-Meter VUCC (#237 4/1988), but understood that this one would be more challenging.
I set up an antenna to monitor the FM broadcast band to help me find potential 2-Meter Es and Meteor scatter paths in the future. To my surprise, on a few occasions I would pick up FM broadcast stations from Tuscon, 175 miles away. So something is enhancing it. I asked for volunteers and luckily Ron Herring, W7HD just north and west of Tuscon volunteered to operate 2-Meter PropNET and see if we could capture each other.
Ron is running 25 watts into a Diamond X50 vertical @ 50 feet and I am running 10-15 watts into a 4-Element F9FT Tonna Yagi @ 25 feet. On occasions I switched to a Cushcraft Ringo Ranger II without the radials (base at 18 feet).
Here are our results for the week-ending 10/18:
Weather was not very cooperative this week.
They were a few low pressure disturbances that passed through the area.
They were a few low pressure disturbances that passed through the area.
Tx Call
|
Tx Grid
|
Rx Call
|
Rx Grid
|
Distance (km)
|
Band
|
Path Score
|
Freq Δ
|
IMD
|
UTC Time
|
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-092
|
60%
|
2014-10-18 14:47:20
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
33%
|
-093
|
80%
|
2014-10-18 12:57:21
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
33%
|
-094
|
-07
|
2014-10-18 12:37:21
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
33%
|
-115
|
99%
|
2014-10-18 11:57:21
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-097
|
-08
|
2014-10-18 11:27:21
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
50%
|
-121
|
99%
|
2014-10-18 10:17:20
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
33%
|
-120
|
40%
|
2014-10-18 10:07:21
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
33%
|
-116
|
80%
|
2014-10-18 09:17:21
| ||
DM34UN
|
DM42JI
|
265
|
2 meters
|
17%
|
+296
|
60%
|
2014-10-18 08:55:29
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
67%
|
-119
|
40%
|
2014-10-18 08:27:21
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
67%
|
-119
|
50%
|
2014-10-18 08:07:21
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
50%
|
-119
|
60%
|
2014-10-18 07:57:21
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
33%
|
-122
|
80%
|
2014-10-18 07:37:21
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-122
|
-14
|
2014-10-18 07:17:21
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-103
|
80%
|
2014-10-17 12:37:22
| ||
DM34UN
|
DM42JI
|
265
|
2 meters
|
17%
|
+184
|
80%
|
2014-10-17 11:25:45
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-109
|
40%
|
2014-10-17 11:17:23
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-109
|
-14
|
2014-10-17 10:17:22
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-113
|
-04
|
2014-10-17 08:57:12
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-115
|
+00
|
2014-10-17 07:37:12
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
67%
|
-121
|
80%
|
2014-10-17 06:07:12
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
50%
|
-124
|
60%
|
2014-10-17 05:47:13
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
33%
|
-124
|
90%
|
2014-10-17 05:37:13
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-126
|
-03
|
2014-10-17 05:27:12
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-124
|
40%
|
2014-10-17 04:17:13
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
50%
|
-088
|
80%
|
2014-10-16 11:27:15
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
33%
|
-083
|
-06
|
2014-10-16 11:17:15
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-086
|
+00
|
2014-10-16 10:47:15
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-113
|
-16
|
2014-10-16 06:37:14
| ||
DM42JI
|
DM34UN
|
265
|
2 meters
|
17%
|
-069
|
80%
|
2014-10-14 06:17:19
| ||
DM34UN
|
DM42JI
|
265
|
2 meters
|
17%
|
-282
|
40%
|
2014-10-12 14:03:07
|
Several times I saw Ron's signal on the waterfall, but the software failed to sync with it. All captures this week was using the Yagi.
What Provides the Enhancement.
My Station
 |
| A Yaesu FT290R driving a THP 30 watt Amp, Janel QSA5 MosFET preamp into a rebuilt Tonna F9FT 4-Element Yagi. All of the equipment is 32 years old! Ron's W7HD signal is being captured in the pic. |
Path
.png) |
| I am located in Prescott Valley. Verde Valley and Black Canyon are to my Southeast. Phoenix is located in a valley and continues as San Tan Valley towards Tucson. |
.png) |
| There are very few obstructions between us. |
.png) |
| The vertical line marks to the direction to W7HD from my QTH. As noted, it is straight down the valley. Only one mountain is in the downward view and it is low on my horizon. |
.png) |
| The view to my station (KA5DWI) from Ron's QTH is noted by the vertical line. He has no obstructions to my QTH |
Weather Conditions Promoting an Opportunity
Week-Ending 10/11/14
First Captures
.png) |
| NWS Radar Mosaic Afternoon of 10/07/14. Tropical Storm Simon was entering the Gulf of California. |
.png) |
| As it approached, the counter-clockwise wind from the low pushed warm air along the eastern border of the valleys. The false echoes (light blue) shows the inversion in the valleys. This provides the conditions for ducting of VHF signals. |
Second Opportunity
 |
| The next opportunity was a surprise on 10/10. The line of very strong thunderstorms formed in the northern Chino Valley. The storms produced hail and started to break up once the sun set. |
 |
| Once the storms died out, the air cleared, the atmosphere stabilized, and winds were fairly light. |
 |
| Upper air winds were also light. That is odd for Thunderstorm formation. The storms had tremendous uplift as observed at my QTH. The result was hail. |
 |
| Upper-Air Soundings-Flagstaff AZ the following morning. Line on left: Dewpoint Line on right:Air Temperature Vertical Axis: Height An inversion occurs when both measurement lines go in opposite directions. Inversion at: 3,100 m, 5,100 m, & 10,000 m. |
 |
| No strong inversions over Tucson, but small ones at 1,500 m and 2,500 m. |
Third Opportunity
 |
| Still wedged between two surface low pressure troughs, little to no wind on the surface. Notice the heat island temperature in Phoenix are 10-20 degrees warmer than the surrounding areas.. |
.gif) |
| Upper level winds are light over Arizona. |
 |
| High pressure is centered over Arizona at mid-levels. |
.gif) |
| There are three inversions over Flagstaff. 4,700 m, 6,700 m, & 10,000 m. |
.gif) |
| Over Tucson, there are well-defined inversions at 1,500 m and 4,700 m. |
Week-Ending 10/18/14 Opportunity
 |
| The NWS Radar Mosiac show once again good temperature inversions in the valleys. |
 |
| Arizona is located this day between 2 surface lines of low pressure (trough and warm front). |
 |
| Very little to no surface winds provide good radiation cooling |
 |
| In the Upper Air, Arizona is located on the backside (left) of high pressure centers. Winds again are light. |
 |
| At both Flagstaff and Tucson there are at least 2 levels of temperature inversions. Air-Temperature increases, Dew Point rapidly decreases |
Tropospheric enhancement and ducting of VHF signals are a matter of having temperature inversions at levels visible to your RF path. The opportunities are there more than you think. Once identified, it is a matter of having someone on the other end.
I hope this can guide you in experiencing the joys of working VHF/UHF weak signal.
73s
Art Jackson KA5DWI/7 DM34un
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