1. Alpha Antenna 10-80m Loop Antenna
Roger Reini, KD8CSE
May 2018

2. Where have I seen this antenna before?
Alpha Antenna have had a presence at local hamfests
This shows the loop antenna set up at the Livonia (LARC) swap in 2017

3. How the antenna arrived
Duffel bag contains all of the antenna components
Optional tripod for mounting the antenna

4. How the antenna arrived
Components of the antenna
Clockwise from upper left: main outer loop for 10-40m; the match box; 3-way SO-239 adapter; expansion loop segment for 40-80m; inner loop for coupling to transceiver; instructions and clips; selfie stick for mounting antenna

5. Shots of the Antenna
Here is the loop antenna set up in 40m configuration, mounted on the tripod (not visible)

6. Shots of the Antenna (continued)
Tuning or Match Box
Closeup of Coupling Loop

7. Shots of the Antenna (continued)
Closeup of mounting clip
Antenna seen in 80m configuration

8. Original Specifications
Frequency Coverage: 7 to 29.7 MHz (3.5 MHz with 80m booster cable)
Maximum Power Rating: 30 W PEP (SSB), 15 W CW, 10 W Digital (20 W PEP SSB on m when booster cable used)
Diameter of loop: approximately 3 feet
Antenna weight: 1.5 lb; tripod, 1 lb; bag, 0.6 lb

9. Upgraded Specifications!
Loops built after Jan. 1, 2018 are rated for up to 100 W PEP SSB, 50 W CW, 25 W Digital for 10-40m (no change for m)
SSB power varies from 98 10m to 59 40m
Older antennas cannot be upgraded

10. Construction
Appears to be simple and quick to set up (but needs practice)
Mount for selfie stick on tuner box did not allow other mounts to face correct direction; had to adjust the orientation of mount (a one-time adjustment)
6 clips and 2 Velcro straps retain the loops to each other (use 2 in 40m configuration

11. Operation Loop antennas have narrow bandwidth, so tuning is critical
Initial tuning: adjust the dial on the matching box for the loudest noise floor
Final tuning for transmitting requires an antenna analyzer or monitoring SWR while tuning with rig
Can use antenna tuner to match, but it will not be ideal

12. Experience
First operated with it April 21, the weekend of Michigan QSO Party
Used 20 W for SSB
Tuned for the loudest noise but did not fine-tune with analyzer: had SWR problems, fixed with antenna tuner but likely at a significant power loss
Did make contacts with stations in IL, MN and MA (the latter a Marconi Day special event station)
Loop seems better suited to camping on a frequency and managing a run as opposed to hunt-and-pounce

13. Experience (continued)
Will want to tune antenna with analyzer for optimum operation
Need to keep antenna remote from operating position, especially at higher power (makes it harder to quickly retune)
Could operate pedestrian mobile by carrying by hand or on backpack
Useful for operating in antenna-challenged locations such as apartments, condos, anyplace with CCR’s

14. Resources Alpha Antenna: http://alphaantenna.com
Page for 10-40/80 loop antenna: s_id=73&zenid=38d9d7668c6bd2cd8c2fd0d69ac8b519
User Guide for loop antenna (May 2018): al_v4.pdf