ATU or IMU?   September 23rd, 2012

ATU or IMU

We’ve all used an ATU at one time or another and many modern radios have an auto ATU fitted inside. Yet in this world of High Tech this very useful device is actually not an Antenna Tuner at all. It has a most misleading name!

In most cases it has absolutely no affect on the antenna resonance or “tuning.” The so called ATU is actually an impedance matching unit (IM). Does the name matter?

Well it does if you believe an ATU brings your antenna to resonance, lowers it’s VSWR or indeed changes anything about the antenna. We all understand that VSWR represents wasted power that is never radiated, but the VSWR on an antenna feeder cannot be removed on the line between antenna and “tuner. So what can an IMU (ATU) achieve? Well the only thing it can do is to provide a match for the transceiver’s 50 Ohm output. That way the transmitter can deliver full power to the antenna feeder. However, the VSWR remains and the losses that result, still remain. In fact there are many losses that occur on HF systems and some of these we will touch on in a future blog entry.

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ICOM Go the Distance   September 20th, 2012

Icom recently announce the introduction of their RC28 remote controller and matching software. This enables Icom owners to remotely control their transceivers over the Internet. Early tests show this to be a stable and simple system to install. It requires PCs at both ends but the remote setup requires no hardware other than the RC28 which is a heavy weight little unit combining VFO, PTT and two programmable functions. All other controls are va the PC screen.. The unit is available at £275 including software.

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Elecraft KX3 From Stock   September 19th, 2012

At long last we can announce that the amazing KX3 is available for almost immediate delivery. There are still some accessories that are in short supply but by October we anticipate all items will be available. We are currently building stock for the Newark Hamfest but demand may outstrip stock so get your order in now and reserve one

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