Dorm room antenna

It's a challenge to deploy an HF antenna on campus. Build and tune this simple 20-m dipole!

Updated 2-12-20

---geometry of installation---

---bill of material---

1:1 voltage balun $15

https://qrpguys.com/qrpguys-11-41-voltage-baluns

Transmission Line 10-feet 50-ohm RG-58u coax $10

https://www.amazon.com/TNP-BNC-Cable-Professional-Oscilloscope/dp/B01IEFMHB2/ref=sr_1_6?keywords=rg-58+coax+cable+BNC&qid=1581564904&sr=8-6

Antenna wire. Silicon insulation should be nicely flexible. 50-ft should suffice $12

https://www.amazon.com/BNTECHGO-Silicone-Flexible-Stranded-Impedance/dp/B01K4QVW1K/ref=sr_1_11?keywords=20+gauge+wire&qid=1581564996&sr=8-11

Clips to Hold Wire Antenna wire is held aloft, high on the inside walls, by "Command Clips" $9

https://www.homedepot.com/p/Command-Clear-Decorating-Clips-Value-Pack-40-Clips-48-Strips-Pack-17026CLRVPES/203431559

Total cost around $50, depends on shipping and tax charged.

---installation process---

The circumference of this sample room is 14' 6" + 10 + = 14' 6" + 10 = 49 feet. The antenna will be held at the junction of the walls and ceiling using "Command Clips" types of fasteners.

Suggest starting with 20 ft of antenna wire on each side of the voltage balun. Using the K7UAZ RigExpert antenna analyzer, measure the resonant frequency... it should be significantly lower than the 20-meter band. Perform a series of

MEASURE resonant freq, low freq at 3:1 SWR, high freq at 3:1 SWR

RECORD RESULTS

CALCULATE how much wire to cut next

CUT WIRE

In this manner you can build an antenna that performs to YOUR needs and wants.