Half Rhombic antenna with counterpoise
The inverted rhombic antenna boasts a distinctive half-rhombic configuration. Its directivity focuses toward the terminated end, enhancing signal precision. Developed…
Month: January 2022
Circuits – LM386 Audio oscillator
LM386 Audio oscillator This one is excellent application of widely used audio amplifier IC LM386.Its output is square wave at…
Terminated End Fed Vee Antenna (TEFV)
Terminated End Fed Vee Antenna (TEFV) Author : D.Prabakaran VU3DXR Figure1 – Terminated End Fed Vee antenna It is a…
Circuits – Simple Crystal Tester
Simple Crystal tester – The idea for this crystal tester circuit sprung out of the need of testing a large…
Circuits – 40M tag QRP Transmitter
Here is another qrp cw transmitter pulled out from SPRAT back issues, which is simple to build with commonly available…
Antenna – Foldaway Loop antenna
This loop antenna is based on one published in one of back issues of sprat by DL1HCU. It worked well…
Antenna – Rockloop HF Antenna for 10,15,20 metre ham bands
Rockloop HF antenna for 10,15,20 metre ham bands The Rockloop HF Antenna ‘s a tuned loop antenna measuring 33 feet…
Circuits – Pippin QRP Transmitter
This pippin QRP transmitter is basically a conventional colpitts type crystal oscillator with output taken from a low value collector…
Circuit – Battery Low Power Indicator
This is a clever Battery low power indicator circuit designed by G3AGX that provides a visual indication when equipment is…
Circuits – 7 Mhz 5 Watts CW Transmitter
The above 7 Mhz 5 Watts CW Transmitter circuit was found in one of back issues of sprat. Still i…