Happy New Year!
I am currently at my home country during the new-year holiday, and had a chance to test “PBA-MLA4 (rev. 2.0) Mini-Whip” antenna, developed by Hokushin Electronic Service in Japan (their Blog site to show this antenna is here, but only in Japanese).
This looks a modified version of the famous PA0RDT Mini-Whip antenna. It uses an op-amp IC chip instead of transistors. The gain can be controlled by pot. The kit came with a PCB and the IC chip. Other parts were obtained by myself.
In the above photo, the lower one is another Mini-Whip based on the original PA0RDT’s design (also available in Japan as a kit), to use for comparison.
The following videos are all Perseus spectra when compared between 1) PBA-MLA4 Mini-Whip, 2) PA0RDT Mini-Whip, 3) LZ1AQ’s AAA-1 Active Loop, and 4) back to PBA-MLA4 Mini-Whip, switching in this order about every 15 seconds. In most cases, PBA-MLA4 gave stronger signals than the original PA0RDT type.
ABC Northern Territory 4835 kHz
Zanzibar Broadcasting Corporation (Swahili) 11735 kHz
Vatican Radio (French) 9660 kHz
Radio Australia 15415 kHz
In the above videos, the Loop antenna actually performed the best. However, I typically use the Mini-Whip in mobile operation (please see “my antenna” page) and this is the best antenna for the car SWLing as it is very small and covers wide bands, without the effect from engine noise. Because of the better signals, I have switched the circuit board to PBA-MLA4. In the same manner as the original one, this active antenna resists the engine noise, so I can enjoy shortwave listening while I am driving!