Geographic location & UHF Satcom

[zguy1243]

Is it me or do stations on the west coast of the United States have better signal quality from the UHF Satcom CONUS satellite? I notice Brandon's recordings at solarix.net have full quieting great signal strength. I have similar antennas to him and top of the line feedline and preamps and cannot duplicate that kind of full quieting signal here in north Georgia. The way I see it the satellite is at a similar elevation also. What could be contributing to the better signal strength beyond ground receiving station performance?

Jody

 

[jsoergel]

Is it me or do stations on the west coast of the United States have better signal quality from the UHF Satcom CONUS satellite? I notice Brandon's recordings at solarix.net have full quieting great signal strength. I have similar antennas to him and top of the line feedline and preamps and cannot duplicate that kind of full quieting signal here in north Georgia. The way I see it the satellite is at a similar elevation also. What could be contributing to the better signal strength beyond ground receiving station performance?

Jody

What's your antenna position like? Is it an omni or a yagi? If the equipment is about the same, I would question the placement.

I'm still new to satcom, but it's a tricky little devil. I still haven't gotten anything besides pirates and a few quick green comms.

 

[zguy1243]

What's your antenna position like? Is it an omni or a yagi? If the equipment is about the same, I would question the placement.

I'm still new to satcom, but it's a tricky little devil. I still haven't gotten anything besides pirates and a few quick green comms.

Thing is there isn't much to it. As long as you have a unobstructed view of the satellites spot in the sky not much can be screwed up. Where we are in relation to the satellite even a good omni will work great. I have a M2 eggbeater made for UHF satcom 250-270 Mhz antenna and a few different Trivec military RHCP military directional models. Without better information, as I am only going on sound his signal strengths just "sounds" better. I thought maybe he was cleaning the audio up with a editing program also.

Another thing on your particular situation being new at satcom listening, There are a few hot freqs that yield a little more activity than others. One of my favorites is 261.85. This freq has all kinds of accidental relays in AM mode. Late at night i have heard GCI stations and unknown fighters with thick accent doing intercepts, some really neat stuff. I do not think that 261.85 relays are coming from the CONUS satellite though. Another to plug is 260.475, this is the Barksdale B-52's satcom freq. They are active very often with clear com checks. Watch Brandons logs, he reports many of the more active freqs. Another neat thing to do is load all the input freqs, you will be surprised to hear how many aircraft passing the your area are talking on satcom. This can also clue you in to their frequency assignments based on cross referencing thier uplink with the downlink. If you have known aircraft in the area most of the time you can make a good guess who is talking even when the comms are green.

Here is a poor video of some of the 261.85 AM relays...

declaredhostile's Channel - YouTube

 

[kf4vhk]

satcom

Hello Jody; where is a list of the input freq. for these birds. Really starting to enjoy this satcom stuff. Got a preamp on the way this week.Not doing bad with the Comet Discone at 30ft. Let me know Thanks

 

[jsoergel]

Hello Jody; where is a list of the input freq. for these birds. Really starting to enjoy this satcom stuff. Got a preamp on the way this week.Not doing bad with the Comet Discone at 30ft. Let me know Thanks

(# - up - down)
1 SHF 250.350
2 SHF 250.400
3 SHF 250.450
4 SHF 250.500
5 SHF 250.550
6 SHF 250.600
7 SHF 250.650
8 SHF 250.700
9 292.850 251.850
10 292.950 251.950
11 293.050 252.050
12 293.150 252.150
13 294.550 253.550
14 294.650 253.650
15 294.750 253.750
16 294.850 253.850
17 296.250 255.250
18 296.350 255.350
19 296.450 255.450
20 296.550 255.550
21 297.850 256.850
22 297.950 256.950
23 298.050 257.050
24 298.150 257.150
25 299.350 258.350
26 299.450 258.450
27 299.550 258.550
28 299.650 258.650
29 306.250 265.250
30 306.350 265.350
31 306.450 265.450
32 306.550 265.550
33 307.750 266.750
34 307.850 266.850
35 307.950 266.950
36 308.050 267.050
37 309.150 268.150
38 309.250 268.250
39 309.350 268.350
40 309.450 268.450
41 310.650 269.650
42 310.750 269.750
43 310.850 269.850
44 310.950 269.950
45 293.950 260.350
46 293.975 260.375
47 294.000 260.400
48 294.025 260.425
49 294.050 260.450
50 294.075 260.475
51 294.100 260.500
52 294.125 260.525
53 294.150 260.550
54 294.175 260.575
55 294.200 260.600
56 294.225 260.625
57 294.250 260.650
58 294.275 260.675
59 294.300 260.700
60 294.325 260.725
61 294.350 260.750
62 294.375 260.775
63 294.400 260.800
64 294.425 260.825
65 294.450 260.850
66 295.050 261.450
67 295.075 261.475
68 295.100 261.500
69 295.125 261.525
70 295.150 261.550
71 295.175 261.575
72 295.200 261.600
73 295.225 261.625
74 295.250 261.650
75 295.275 261.675
76 295.300 261.700
77 295.325 261.725
78 295.350 261.750
79 295.375 261.775
80 295.400 261.800
81 295.425 261.825
82 295.450 261.850
83 295.475 261.875
84 295.500 261.900
85 295.525 261.925
86 295.550 261.950
87 295.650 262.050
88 295.675 262.075
89 295.700 262.100
90 295.725 262.125
91 295.750 262.150
92 295.775 262.175
93 295.800 262.200
94 295.825 262.225
95 295.850 262.250
96 295.875 262.275
97 295.900 262.300
98 295.925 262.325
99 295.950 262.350
100 295.975 262.375
101 296.000 262.400
102 296.025 262.425
103 296.050 262.450
104 296.075 262.475
105 296.100 262.500
106 296.125 262.525
107 296.150 262.550
108 297.150 263.550
109 297.175 263.575
110 297.200 263.600
111 297.225 263.625
112 297.250 263.650
113 297.275 263.675
114 297.300 263.700
115 297.325 263.725
116 297.350 263.750
117 297.375 263.775
118 297.400 263.800
119 297.425 263.825
120 297.450 263.850
121 297.475 263.875
122 297.500 263.900
123 297.525 263.925
124 297.550 263.950
125 297.575 263.975
126 297.600 264.000
127 297.625 264.025
128 297.650 264.050
129 302.445 248.845
130 302.450 248.850
131 302.455 248.855
132 302.465 248.865
133 302.475 248.875
134 302.485 248.885
135 302.495 248.895
136 302.500 248.900
137 302.505 248.905
138 302.515 248.915
139 302.525 248.925
140 302.535 248.935
141 302.545 248.945
142 302.550 248.950
143 302.555 248.955
144 302.565 248.965
145 302.575 248.975
146 302.585 248.985
147 302.595 248.995
148 302.600 249.000
149 302.605 249.005
150 302.615 249.015
151 302.625 249.025
152 302.635 249.035
153 302.645 249.045
154 302.650 249.050
155 302.655 249.055
156 302.665 249.065
157 302.675 249.075
158 302.685 249.085
159 302.695 249.095
160 302.700 249.100
161 302.705 249.105
162 302.715 249.115
163 302.725 249.125
164 302.735 249.135
165 302.745 249.145
166 302.750 249.150
167 302.755 249.155
168 302.765 249.165
169 302.775 249.175
170 302.785 249.185
171 302.795 249.195
172 302.800 249.200
173 302.805 249.205
174 302.815 249.215
175 302.825 249.225
176 302.835 249.235
177 302.845 249.245
178 302.850 249.250
179 302.855 249.255
180 302.865 249.265
181 302.875 249.275
182 302.885 249.285
183 302.895 249.295
184 302.900 249.300
185 302.905 249.305
186 302.915 249.315
187 302.925 249.325
188 302.935 249.335
189 302.945 249.345
190 302.950 249.350
191 302.955 249.355
192 307.750 254.150
193 311.150 257.550
194 316.955 243.855
195 316.960 243.860
196 316.975 243.875
197 317.000 243.900
198 317.010 243.910
199 317.015 243.915
200 317.025 243.925
201 317.035 243.935
202 317.045 243.945
203 317.055 243.955
204 317.065 243.965
205 317.075 243.975
206 317.085 243.985
207 317.090 243.990
208 317.095 243.995
209 317.100 244.000
210 317.105 244.005
211 317.110 244.010
212 317.115 244.015
213 317.125 244.025
214 317.135 244.035
215 317.145 244.045
216 317.155 244.055
217 317.165 244.065
218 317.175 244.075
219 317.185 244.085
220 317.190 244.090
221 317.195 244.095
222 317.200 244.100
223 317.205 244.105
224 317.210 244.110
225 317.215 244.115
226 317.225 244.125
227 317.235 244.135
228 317.245 244.145
229 317.255 244.155
230 317.265 244.165
231 317.275 244.175
232 317.285 244.185
233 317.290 244.190
234 317.295 244.195
235 317.300 244.200
236 317.305 244.205
237 317.310 244.210
238 317.315 244.215
239 317.325 244.225
240 307.550 253.950
241 307.700 254.100
242 311.050 257.450
243 311.200 257.600
244 307.750 254.150
245 311.250 257.650
246 307.650 254.050
247 311.150 257.550
248 294.800-314.800 253.650-254.350
249 298.300-313.300 257.150-257.850

 

[jack103]

Sorry but is this info still good

Is this info for sat freqs AM mode. ?

 

[mancow]

They are FM.

 

[prcguy]

It could be the actual satellite at the particular orbital slot that is giving better downlink signal strength. From the west coast we can hear the sats over Hawaii and I can usually pick them up inside my house with a rubber duck on a Yupi 7100 just fine. That particular satellite is a newer Hughes/Boeing UHF Follow On and I'm not sure how many UHF sats have been replaced with newer and seemingly hotter birds.

Also, at a high look angle from your antennas perspective you can pretty much work the link budget if you know the satellite EIRP, your antenna gain and receiver characteristics. But at a very low look angle you have ground noise added to the link budget and possibly some ground bounce that can sometimes reinforce or degrade reception, although with circular pol the pol swaps with a single bounce and should not cause much trouble.
prcguy

 

[jlh]

jody, i'm in central north carolina so i'm not far from you. when i did satcom, maybe 10 years ago?, i used a homebuilt yagi and had good signal strength and quiet audio. of course, over time i guess the satellites/equipment may have changed but i don't think we are geographically-challenged in dixie.

 

[KR0SIV]

Hello Jody; where is a list of the input freq. for these birds. Really starting to enjoy this satcom stuff. Got a preamp on the way this week.Not doing bad with the Comet Discone at 30ft. Let me know Thanks

Glad your having fun, don't be playing on those up-links now XD

 

[krokus]

I didn't see anyone mention the footprint of the birds, and how that affects the available signal in an area.

Most US military UHF birds are focused on oceans, with some coverage on various land masses. Thusly, the bird(s) covering the Pacific Ocean will not provide a good signal to mid-CONUS and east of there.