The EH Antenna
23 cm tall (!)
|
I had already tested the EH Antenna on a portable transceiver and compared the RF radiadion to a 24 cm Helical "Rubber duck" and a 72 cm Glassfiber Whip. This test can be found under " A Comparison between different antennas on a cb portable", AN ERP TEST, which is a PDF document. But how does the EH Antenna perform against a 1/4 wave Ground Plane Antenna? So, said and done. I borrowed a GP from a friend who had one for field operations, and mounted it on a telescopic mast. I placed the GP in the garden 6 meters from the house wall. No doubt, there was increased signals in the receiver and the reports from other stations verified the increased signal from my transmitter. The SWR was measured to 1,3 : 1 for the GP at 27.235 MHz.
Well, then - how much difference is there? I placed the GP on the roof terrace and set it to the same height as the EH Antenna. The tests were made against fixed Packet Radio Nodes, all in line of sight. I decided to record the S-meter readings using an attenuator at the receiver. By doing so I could set the S-meter reading to a point where the readings were in the linear part of the S-meter.
It was possible to connect to three PR Nodes with the EH Antenna. The GP Antenna found another five! The signals were carefully recorded, and after every reading the antenna was substituted with the Stabilock 4040 Signal Generator. The corresponding level from the generator was noted and recorded in the list of nodes.
CONCLUSION:
The EH Antenna works. But it does not work as well as a GP antenna. On the average, the EH Antenna was 12 dB down on the GP. To the EH Antenna's favour is its size - it is about 5% of the GP.
|
The GP Antenna - in all 4,5 meters high from top to the bottom
Half Wave 27 MHz. With SWR 1,2 : 1 it only improved 0.3 ... 0.5 dB compared to the GP. This monster is 6 meters tall!
|
