Tests with 80m magnetic loop antenna
Magnetic ferrite rod antennas are common in portable bc radios. Same principle can be used also for HF communication antennas (without ferrite rod). OH7SV motivated me to replicate and continue his magnetic loop antenna tests. All you need is open mind, beautiful summer evening and few meters copper tubing.
Test loop diameters & other spec.
Main loop total length 10m. Antenna active length is about 9m. Feed loop length 1,8m. Tuning capacitor about 150 pF.
OH2NLT test station at Sipoo
Johannes OH2GSP and material for magnetic loop
Test antenna erected and ready for testing
Fine-tuning. BTW bandwidth of the antenna in single tune point is only about 10 kHZ
Feed loop. Feed loop has been tested also for 2 m loop.
Tuning capacitor. Only problem found during tests was tuning capacitor voltage rating. Across tuning capacitor exist several kilo volt voltages. With normal air insulated capacitor only about 20W power can be used.
In august 80m loop got little brother. Few pictures of 2m test loop.
OH7SV Magnetic loop tests
OH7SV Loop calculator