2024-12-15

SOTA W7W/KG-113 Rattlesnake Mtn

Overview

Summit

• W7W/KG-113 Rattlesnake Mountain, WA

Elevation and temperature data

Parking at 930', 34 degrees
Snow at 2000', ~30 degrees
Summit at 3400', ~26 degrees

Plan of Operation

Activation details:

• Operator 1: KF7RQ Doug
• Operator 2: AA6EI Shane
• SOTAWatch alert submitted day prior
• SOTAWatch self-spot via ‘SOTA Goat’ at activation site
• locator: CN97CK38NH (latitude: 47.45183696749011 longitude: -121.80413042893635)
• 2m LOS mapping
• GPS track — Strava

Antennas:

• 2m roll-up J-pole (homemade by KF7RQ)
• EFHW Bugout Mini Antenna 40-10m, great SWR, no tuner
• SOTABeams Tactical Mini holding EFHW 18’ sloping to 5’ tied off to a tall trail sign post, broadside SW/NE.

Log

20m very crowded.

10m fairly crowded but found a quiet spot on 28.630.

28.630 USB

Callsign  PST   UTC   Recvd
WW7D      1136  1936  4-2
WA7BEN    1138  1938  3-9
KF6HI     1141  1941  4-2
WA7OOO    1142  1942  3-9

Signal Report Analysis

Operating a shared transceiver. I didn’t log sent signal reports. All stations where strong and easy to copy, 5-7 to 5-9+. The received signal reports of 3-9 on 10m SSB I suspect is an issue with local ground-wave propagation from Rattlesnake Mtn to Seattle. Got a 4-2 report from Indiana using 2.5 Watts!

Antenna System Analysis

EFHW oriented at 320/140 degrees, running along the axis between North Bend and Whidbey Island. Broadside (perpendicular) to the antenna would be 230/50 degrees. That orients Auburn and Olympia to the Southwest, and Glacier Peak to the Northeast. Initially I thought the orientation was 90 degrees to what we had. The combination of near-field obstructions (mountains), strong nearby stations (QRM), and less than ideal antenna orientation may have all played a role in lower than expected readability reports. Next outing I would like to request feedback on audio levels and signal quality to understand if adjusting mic gain might also help.

Conclusion

Had a great time on the mountain and it was fun hiking through the snow. This was my first deployment of the Reliance EFHW antenna. It worked very well in sloper configuration (top-fed at 18’).

Hiking party

• Doug (KF7RQ)
• Sam the SOTA dog
• Miguel
• Dave
• Shane (AA6EI)

After 30 minutes of setup, finding an open spot on the band, and making some contacts, we packed up and got moving down the mountain. On the way home we stopped at Huxdotter Coffee in North Bend for coffee and snacks.