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70cm slot antenna


70cm slot antenna

70cm slot antenna

post 10 Sep 2024


Antenna for UHF VHF Links

153



Quadrifilar helicoidal antenna - Photos
Detailed view of the balun J-J used RG-400, too rigid to bend and pass through the tubing

Quadrifilar Antenna to receive 137 MGHz
Creation of a four-wire antenna to receive the 137 MHz signal from NOAA meteorological satellites

Swiss quad for 144Mhz
This antenna can be made for 50 or 28 MHz. The length of the elements is given at the bottom of the description

The 2 Element HB9CV Beam
The Beam is a coax-fed version of the ZL-Special. The reflector is fed 225 out of phase

The 2m/70cm yagi Project

3 elements on 2 meters and 4 elements on 70 centimeters


23cm Yagi Antenna building

23cm Yagi Antenna building Finished antenna at 1275 MHz SWR under 1:1.5 at resonant frequency

50 MHz preamp Gain 26dB with the BFG135

50 MHz preamp Gain 26dB with the BFG135 Preamps for 144 and 430 MHz, for 50 MHz, the BFG135a is a cheap transistor and in my view rather strong. It is not easily damaged by static discharge or RF power. FG connection

30 Volt Computer Power Supply Stack

30 Volt Computer Power Supply Stack A bonus was that i discovered that these did not need a standby load connected to the supply to keep them running just apply mains power and close the Start lead to ground