ACMA Advanced Amateur Radio Theory case studies
ACMA Advanced Amateur Radio Theory · Put your knowledge to work in context.
The Advanced Amateur Operator Certificate of Proficiency (theory) is the Australian qualification that sits above the Standard licence and unlocks the full amateur bands and higher power limits. It suits operators who have outgrown the Foundation and Standard privileges and want access to all HF segments, more modes, and the technical depth needed to build and repair their own equipment. The ACMA Advanced Amateur Radio Theory case studies are 5 cases and about 3,525 words.
1Decibel Budget on a 630 m Experimental Station
An advanced licensee is setting up a low-power station on the 630 m band (472–479 kHz). The exciter delivers 200 mW into a 50 Ω load.
665 words, about 3 min2Oscillator Instability in a 144 MHz Transverter
A homebrew 144 MHz transverter uses a 116 MHz Colpitts oscillator followed by a buffer, a ×2 multiplier, and a 144 MHz amplifier. The builder reports that the local oscillator (LO) frequency drifts 3 kHz over the first 20 minutes after power-on and then wanders ±400 Hz over the next hour.
665 words, about 3 min3Feedline Loss and Antenna Tuner Placement on 80 m
An operator has a 40 m long dipole fed with 45 m of RG-213 coax (loss 1.2 dB/30 m at 3.5 MHz when matched). The antenna is cut for 3.75 MHz but the operator wants to work 3.5–3.8 MHz.
770 words, about 4 min4Digital Mode Interference and Receiver Overload on 20 m
An operator running FT8 on 14.074 MHz with 50 W into a dipole reports that the receiver's AGC pumps heavily and the waterfall shows strong signals across the band. A nearby station 2 km away runs 1 kW on 14.080 MHz.
679 words, about 3 min5RF Exposure Compliance at a Rooftop Vertical
An advanced licensee installs a 5/8 λ vertical for 2 m on a rooftop. The antenna's feedpoint is 3 m above the roof, and the roof is accessible to the licensee and family.
746 words, about 4 min