Amateur Radio, Meteology and Astronomy website. JO10UX
Antenna splitter for Broadcast and 144 MHz
Driving a car owned by the firm I work, I had the choice of using a magnetic
antenna or finding an other solution. A magnetic antenna has the risk of being
removed somewhere so I started looking for the other solution. In a VHF
Communications of spring 1978 I found a project of an antenna splitter designed
by DK1OF. The Idea is to use a 2mtr. mobile antenna
with a 2 mtr. transceiver and a broadcast radio.
Not only the schematics where described but also the theory and the formula's to compute the components. This made it possible to recalculate the whole thing for my proper use. The original concept used as center frequency of 95 MHz for the FM-Broadcast there where I use to listen to stations centered around 91 MHz. As a center frequency for 2 mtr. I used 145MHz.
R = Input impedance = Output impedance = (50 Ω)
F1 = Cut-Off frequency Broadcast (91 MHz)
F2 = Center Frequency off 2 mtr. (145 MHz)
The theoretical frequency response:
1) The response from the antenna to the 2 Mtr. Transceiver:
2) The response from the antenna to the Broadcast radio:
The next step is to work-out the project in a practical way.
Design of a printed circuit:
Solder-side seen from components
Earth-mask on the component side
Position of the components:
... to be continued.
سُوۡرَةُ حٰمٓ السجدة / فُصّلَت
Surah Fussilat: Thereafter turned He to the heaven and it was as smoke, and said Unto it and Unto the earth: come ye twain, willingly or loth. They said: we come willingly. (11) Then He decreed them as seven heavens in two days, and revealed Unto each heaven the command thereof; and We bedecked the nether heaven with lamps and placed therein a guard. That is the ordinance of the Mighty, the Knower. (12)
De hemelen en aarde (waren) een samenhangende massa. Wij hebben ze toen van elkaar gescheiden… Wij hebben de hemel tot een beschermend dak gemaakt … en de dag en de nacht, de zon en de maan geschapen. (Koran 41 11:12)