VE7BQH publishes a table of Yagi performance data derived from a number of modelling programmes. The table is often used as a definitive reference of the overall merit of an antenna by buyers, makers and students for their own situation.
This article is mainly motivated at better understanding the G/T column of the tables. Continue reading Trying to make sense of the VE7BQH Yagi performance tables
A correspondent is designing a high performance transverter from 144MHz to 28MHz to be used with a Elecraft K3 transceiver.
A question that arises is just how good should the performance of the transverter be, what Noise Figure and Gain should it have without having performance that cannot be fully realised due to external noise. Continue reading High performance 144MHz transverter design workup – noise and gain analysis
NFM has been updated to v1.18.0.
It includes for user convenience, a noise measurement uncertainty calculator based on the discussion of uncertainty of the noise sampling process at (Duffy 2007b) and the calculator at (Duffy 2007c)
An article in a series documenting measurements on an IC-7410.
This focuses on receiver Tx power and SWR meter.
An article in a series documenting measurements on an IC-7410.
This focuses on receiver Noise Figure.
An article in a series documenting measurements on an IC-7410.
This focuses on digital audio output level encoding headroom.
An article in a series documenting measurements on an IC-7410.
A common method of making Noise Figure measurements of a receiver is to use a noise generator of known noise power. The output power of the DUT is measured with the generator off (NoiseLo) and on (NoiseHi), a Y factor calculated, and from that Noise Figure is calculated.
Continue reading Using an attenuator for NoiseLo/NoiseHi in NFM
This series of seven articles has:
Continue reading Designing high performance VHF/UHF receive systems – Part 7
G/T can be measured using celestial noise sources provided the antenna can be pointed to them. The noise source that is most appropriate will depend on expected G/T, frequency, time etc.
Continue reading Designing high performance VHF/UHF receive systems – Part 6
