Friday, August 12, 2011

The Clifton Labs Z1501 Active Antenna - Pt 1 The Hardware

Conventional wisdom says that MW DX-ers use beverages whenever they can. And if they can't, they use loops of various sizes and properties. So what about whips? Noooo, serious MW DX-ers don't use whips. Whips are for FM or VHF. Only if nothing else works or is possible to erect (including a five cm ferrite bar), will a serious MW DX-er even remotely think about mounting a whip.

Time to think again. Whips with good performance have been around a while. Many NDB DX-ers have successfully used Roelof Bakker's "Mini-Whip", an excellent proof that size doesn't always matter. I've had the Mini-Whip myself a couple of years, and although it has never outperformed my beverages and QDFA, it is an excellent device.

For quite some time I have wondered about purchasing another whip. This summer I finally decided to go for it - not that I really needed it (and I don't think it will outperform my beverages and QDFA), but I was curious if it could perform even better than Roelof's mini antenna.

The Z1501 is sold with either a 1.5 m or a 3 m whip. I chose both, since it was only USD 16 extra.

The Z1501 is an electric field responding “active” antenna, employing a high impedance field effect transistor input stage to efficiently couple electromagnetic field from a physically short antenna to a low impedance (50 ohms) load. The most effective frequency range is 20 kHz to 30 MHz. The size of the weatherproof enclosure is 114x63x25 mm mounted on a larger mounting flange. It has a female BNC connector for 50 ohm coax feedline.

In-house is a DC coupler which delivers 9-24 VDC to the antenna. It can also be used with other active antennas - I have used the Mini-Whip with it with good results.
Enclosure and mounting flange. BNC out to the left.

Telescoped whips, 1.5 and 3 meters

DC Coupler back panel

DC Coupler front panel with green LED

The Z1501 is bought as a kit or assembled. Knowing how soldering limitations, I opted for the assembled version.

So how does it perform? We will soon find out.

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