Quote:
Originally Posted by RobinBirch
I know nothing about noise bridges but am intrigued by this and may have a go at building one. However, reading the paper you reference it says to connect the antenna to one socket on the bridge and tune using the antenna coupler. Won't this just have the effect of transmitting white noise to all and sundry?
|
They are extremely useful bits of gear if you have a receiver around.
They don't radiate anything of significance, certainly several orders of magnitude less than keying down and reading the SWR meter. Mine kicks out less than a couple of mV of noise.
The objective is to get an impedance match so the point at which there is the least noise returned back down the feed at the selected frequency on the receiver then the impedance of the source (receiver) and load (antenna) are matched. You can use them for tuning input and output matching networks to a specific impedance to.
If you ever get your hands on a spectrum analyser they can be used for measuring filter responses as well by injecting the noise in one end and looking at the response on the output (40m LPF here):
That SA is now gone unfortunately. It caused marital problems
