AMATEUR RADIO FOR THE GREAT OUTDOORS
Antennas including linked dipoles, telescopic poles also ham radio kits - everything you need.
If you are thinking of leaving your ham shack with your radio, take a look. We can help.
Posted by Richard Newstead on 24th Apr 2017
Both beaming at Europe from USA.
Distance between antennas = 64 m (3.2 wavelengths)
N = 277, Average = 2.7, STD=1.9, Minimum distance = 5000 km
Difference lies between 1.1dB and -6.5dB (95% confidence)
Today, April 23rd 2017. I carried out a similar experiment to yesterday but with WSPRlite G33CWI reduced in power by 3dB compared the WSPRlite G31CWI. 57 simultaneous S/N readings from stations all over 500km away were gathered.The results distribution is shown below;X=Number of samples, Y=difference in dBThe mean was 2.5dB, The mode was 3db and the standard deviation was 1.6dB.As the [...]
Radio amateurs making measurement tend to just believe any figures they see. This leads to various wildly incorrect interpretations of the data. Antenna testing in particular is prone to all sorts of errors. To understand what readings mean, the errors must be quantified and investigated. This is an experiment carried out to compare two identical [...]
MethodA Chameleon P-Loop and an Alexloop were erected in an open flat area. The area was clear of any obstructions. The antennas were 30 metres apart and orientated in the same way (approx. 064 mag). they were placed so that they sat in the predicted nulls of each other to reduce interactions. The base of [...]
The Alex Loop is a popular commercial small transmitting loop antenna.Measurements here are simply an aide-memoire for my own experiments. They should be used with caution.Loop conductor Datalink DLC 213 premium (3.1m circumference). Conductor diameter 7.4 mm.12-Mar-2017SWR measuring instrument KVE60C Rev D4.01Antenna in clear area. Centre of loop 3.3 m above ground level. Measurements made at the [...]
Comparing HF antennas is not a straightforward task. Radio amateurs have used a variety of methods over the decades but few stand much in the way of scrutiny when it comes to examining their validity. Most of the problems stem from poor methodology, inadequate validation or insufficient data.This experiment seeks to examine the validity of [...]
WSPRlite is a great little tools for DXpeditioners. Few DXpeditions are on all bands 24/7 so WSPRlite is the perfect way to use your antennas to maintain a presence while you are on other bands, sleeping or sight-seeing. Because it is so small you can take it in your pocket - and still get Worldwide [...]
This is a preliminary experiment to compare the performance of two commercial small transmitting loops on 14 MHz. The loops were set up in a suburban garden, 20 metres apart. They were aligned with their nulls N-S and the loops were positioned N-S of each other to minimise coupling. The loops were approximately the same [...]
DXplorer.net opens up a new way to measure antenna performance. 3dB is the smallest change that is generally considered as being audibly detectable on a standard communications circuit and so I wondered how well DXplorer.net would work at detecting this change under controlled conditions.Two antennas were used for this experiment: a doublet, 43m long and 10m [...]
Small transmitting loop antennas "magnetic loops" have become very popular. There is no doubt that they can provide good performance for their small size. While they are easy to build if you have (or can make) a suitable variable capacitor, many people opt for a commercial product. This usually means that the first opportunity to [...]