Martin Ehrenfried (G8JNJ) conducted some interesting experiments on a small transmitting loop.
The loop above is 3.45m perimeter of LDF4-50A Heliax, and uses the full length of the Heliax as a stub for tuning the loop to 5MHz. Continue reading Thermograph of small transmitting loop
This article explores the radiation efficiency of KP4MD’s (Milazzo 2012) small transmitting loop (STL) using a set of NEC-4 models of the loop at varying heights above ‘average’ ground. Continue reading Ground effects on KP4MD’s 0.9m loop on 28MHz
I thought it interesting to compare EMR calc with NEC-4 on my lossless octagonal loop (top tuned), 1m across on 40m in free space radiating 1W. Continue reading Small transmitting loop EMR safety – EMR Calc predictions
This article explores the radiation efficiency of a small transmitting loop (STL) using a set of NEC-4 models of a 3.14m perimeter loop on 7MHz at varying heights above ‘average’ ground. Continue reading Ground effects on small transmitting loop efficiency
Small transmitting loops (STL) are often recommended for use inside buildings, on balconies and even hand held, but are they EMR safe?
Continue reading Small transmitting loops and EMR safety
A common method of feeding a small transmitting loop is to use a small auxiliary input loop. This is sometimes referred to as the “Faraday feed”, implying a shielded feed loop though many so-called shielded loops are not effective (Duffy 2007), but the loop does not need to be shielded nor does there need to be a metallic connection to the main loop.
This article looks at an equivalent circuit. Continue reading Equivalent circuit of small transmitting loop with auxiliary loop feed
One of the feed arrangements used for small transmitting loops (STL) is the so-called gamma match, though it is questionable if these are quite the same as matches of the same name on a linear dipole. Continue reading Small transmitting loop – gamma match
This article describes a linear circuit model for a small transmitting loop with auxiliary loop feed. Continue reading Small transmitting loop – linear circuit analysis
This article describes a NEC-4 model for a small transmitting loop with auxiliary loop feed. Continue reading Small transmitting loop – NEC-4 analysis
I have spoken in several recent articles about antennas that exhibit a simple series resonance with constant or near constant R near resonance.
Sometimes the impedance transformation used may hide that simplicity. Continue reading Simple resonators might not appear as such initially