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Measuring Complex Impedances using the H...

Measuring Complex Impedances using the HP8405A Vector Voltmeter

Measuring Complex Impedances using the HP8405A Vector Voltmeter and a Return Loss Bridge Measuring complex impedances above 1000Ω is usually not possible with the average Antenna analyser however using a return loss bridge and a Vector Voltmeter this becomes possible. With a return loss bridge the amplitude and phase reading of the Vector Voltmeter represent […]

L Network Impedance matching

The tools required for calculating the vales in an L Network come from the following equations that can be found in the ARRL Handbook. XS = QRs and Xp=Rp/Q Q=Xs/Rs and Q=Rp/Xp Rp=Rs(Q^2+1) Rs=Rp/〖(Q〗^2+1) Q=√(RP/Rs-1) The L network is based on a technique known as series to parallel transformations.

Is Reflected Power Lost Power?

Is Reflected Power Lost Power?

After reading a number of articles by the late Walter Maxwell W2DU ARRL technical adviser, I was prompted to carry out some of my own experiments with mismatched loads. I carried out a couple of similar experiments that Walter described in chapter 19A of his book “Reflections”. My experiments were not as comprehensive as those […]

The Slim Jim Antenna

The Slim Jim Antenna

Does the Slim Jim live up to its reputation? There are those that swear by it or those that have serious doubts about its claimed performance. I have to admit I was in the second group. It is my understanding after a reasonable amount of research following many a Google search that the Slim Jim […]

What does your SWR meter tell you?

Probably the first question that should be asked is, what is SWR? Simply put, SWR is the ratio of the maximum voltage (resulting from the interaction of incident and reflected voltages along a transmission line)to the minimum voltage. In a correctly terminated line (that is where the load is equal to the characteristic impedance of […]