TEP VHF DX at Broome, Western Australia

Tony Mann



During a brief stay in Broome, Western Australia (18 S, 122 E), about 1000 miles north of my usual QTH, I logged some evening TEP VHF DX up to 85.25 MHz, mostly from China (channels C1, C2, C3, C4, C5). There were also, as yet unidentified, system M signals as high as chA5 (77.25/81.75) and chA6 video (83.25), and Thailand on channels E2, E3 and E4.

Below is my log for 17-20 Sept. All times UTC (local minus 8 hours).

Equipment, hand-held Yupiteru MVT-7100 scanner with 1.5 meter loaded whip antenna (Diamond RH-205) a few meters above sea level. chA6 audio (87.75) was rendered inaudible by a local FM station on 88.0 MHz

17 Sept

0750- up to 37.5 Asian communications.
0930 49.75 C1 video

Evening TEP

1100- 49.75 C1 video (strong!)
50.018 CW beacon, JA6YBR
1109- 57.75 C2 video (2nd strongest)
1120- 55.249 A2 video (60 Hz)
1155- 65.752 C3 video
65.750 C3 video
(after 1155 UTC all signals with rapid fade, "sleigh-bell" sound)
1200 56.25 C1 audio
48.250 E2 video
1206 64.25 C2 audio
1208- 1245 77.250 C4 video
1222- 48.2499 E2 video
1222- 1318 85.2507 C5 video (weak)
1227 61.250 A3 video (60 Hz)
1245- 1318 77.25 A5 video (60 Hz) overriding C4!
81.75 A5 audio: Chinese! (Taiwan? Korea ??)
1252 83.2498 A6 video (60 Hz) (?)
55.2396 E3 video
55.2495 E3 video
55.2499 E3 video (main tx)
55.2604 E3 video
1300 48.2512 E2 video, Limbang, E. Malaysia
48.2396 E2 video
48.2604 E2 video
1318 67.250 A3 video (60 Hz)
72.25 C3 audio
1415 only 49.75, 57.75 and 65.75 still in.
(also 33.00 continuous data tx, JA)

18 Sept

0100 33.00 continuous data tx, JA
35.58 AM, BBC harmonic Thailand
0340 49.75 C1 video (gone by 0540)
48.2500 E2 video (main tx)
48.2396 E2 video
48.2604 E2 video
0820, 0930 49.75 C1 video (gone by 0945)
1100 no DX - some magnetic disturbance
evening TEP
1415 -1450 49.75 C1 video back
with rapid fade, "sleigh-bell" sound

19 Sept

0030 37.4 MUF to Asia
0137 -0941 49.75 C1 video (in all day and strong!)
0137 35.58 AM, BBC WS
0250 36.68 FM, "2 tone" Costa Rican pager
0500 49.750 very unstable tx in mess of C1 video
50.010 CW beacon, JA2IGY
50.018 CW beacon, JA6YBR
0510 49.75 briefly faded out but JA beacons still in.
0713 34.505 AM?, OM EE accent (Indian?)"...alpha...over"
0727- 35-39MHz wall-to-wall Asian comms.
0739 46.172 RTQ0 video, weak (F2 b/s)
0811 55.249 video, weak
0823 50.010 CW beacon, JA2IGY
50.018 CW beacon, JA6YBR
50.024 CW beacon, JA1ZYK, weak
50.027 CW beacon, JE7YNQ, weak

Evening TEP (all signals with rapid fade, "sleigh-bell" sound)
1059- 49.75 C1 video, strong
55.2492 ? video
55.2498 ? video
56.25 C1 audio
57.75 C2 video (2nd strongest)
61.250 A3 video (60 Hz)
64.25 C2 audio
67.25 A3 video (60 Hz)
77.250 C4 video
85.25 C5 video (very weak)
1107 59.2500 R2 video (very weak)
48.2396 E2 video
48.2604 E2 video
67.2502 A3 video (60 Hz)
67.2600 A3 video (60 Hz)
1116 71.75 A3 audio
1119- 1354 77.250 C4 video (also 77.240, 77.246, but no 77.260)
1125 -1304 85.250 C5 video (very weak) - also 85.2507
1127 55.2501 A2 video (60 Hz), main tx, strong
55.2486 A2 video
1131 65.75 C3 video (may have been in earlier):
65.7431, 65.7439, 65.7459 ,65.7476, 65.750 (mess),
65.7524, 65.7598.
1145 72.25 C3 audio
48.250 E2 video, slow fade
55.2498 A2 video (60 Hz) main,55.2506,55.2483,55.2511
59.75 A2 audio: drama in Asian language; at
1158 two programs, one in US EE.
61.2498 A3 video
55.73 FM STL in JA, OM in JJ
1206 48.2512 E2 video, Limbang, E. Malaysia
48.2498 E2 video, strong
1215 62.2499 E4 video
53.75 E2 audio
50.010 CW beacon, JA2IGY
50.018 CW beacon, JA6YBR
1239 55.2395, 55.2484, 55.2604, video
1245 53.75 E2 audio: Thai
62.2392,62.2488, 62.2498,62.2598 & 62.2601 strong, E4 video
60.75 E3 audio
67.75 E4 audio
1258 60.75 E3 audio: Thai, 2 programs
1301 one parallel to 53.75.
1304 55.73 FM STL in JA, OM in JJ
57.47 FM STL in JA, weak
1307 59.2559 ? R2, weak
1354 -1409 77.25 A5 video (60Hz)
81.75 A5 audio
60.75 E3 audio: drama, Thai
62.2392, 62.2399, 62.2489, 62.2497 E4 video
1404 55.250 (2 txs) E3 video, strong, also 55.2395, 55.2603.
1409 still 48.25, 49.75 strong!,55.25, 57.75, 64.25, 65.75
1520 only 48.25, 49.75, 55.25, 57.75, 65.75
1555 49.75 still in

20 Sept

0100 36.68 FM, "2 tone" Costa Rican pager
MUF to Asia 38 MHz
0220 -0250 49.75 C1 video
0250 36.68 FM, "2 tone" Costa Rican pager, strong.

Relative signal strengths of evening TEP DX, at the base of the scanner antenna:

48.25 E2, Thailand   32 dB
49.75  C1   32 dB
55.25  A2/E3   20 dB
57.75   C2 20 dB
65.75  C3   10 dB
67.25  A4   3 dB
77.25   C4/A5   10 dB
85.25 C5    0 dB

I think it's a reasonable bet that, except for large magnetic disturbances (A index > 40), evening TEP MUFs near 80 MHz are a nightly occurrence in northern Australia during the equinoxes when the solar flux reaches 170-200. So rather than wait for that rare intense Es link-up in October or November, I would encourage other interested Australian DXers to take a short vacation to the tropics during the equinox to sample this otherwise rare phenomenon.

I also logged an FM station in Denpasar, Bali on 99.15 MHz via tropo at 1345 UTC on 19 Sept, at a distance of 800 miles. The receiver was a Panasonic RF-B65 PLL portable with just its own whip antenna 1.5 meters above ground.

73,

Dr. Tony Mann,

Department of Physics,
University of Western Australia,
Perth, Western Australia.
(32 S, 116 E)

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