At 1420 MHz (the hydrogen line), the lowest system noise temperature an amateur can realistically achieve depends on the quality of the antenna, feed, low-noise amplifier (LNA), and how much…
For a 1.2 m prime-focus parabolic dish, the beamwidth depends mainly on the operating frequency (or wavelength), not strongly on the F/D ratio. A typical prime-focus dish has an F/D…
With a 1 m dish, observing astronomical masers is challenging but not impossible if you use a low-noise receiver and target the strongest sources. The most practical maser lines are:…
The Norsat 9000LD series is a professional Ka-band DRO LNB used for satellite communications rather than consumer satellite TV. Norsat still lists the 9000L series as a current product. I…
To add three logarithms with the same base: log(a) + log(b) + log(c) = log(abc) Example: log10(2) + log10(3) + log10(5) = log10(2 * 3 * 5) = log10(30) If…
Radio astronomers use temperature because the random electrical noise generated by a resistor is directly proportional to its physical temperature. This creates a natural link between thermal physics and radio…
For the Parkside 12V cordless polisher/sander (the 75 mm model), there is little practical difference between using a PAPK 12 A3 and a PAPK 12 A4 battery. Both are 12…
In radio astronomy, several different “temperatures” are used to describe sources of noise. They are all expressed in Kelvin (K) because radio noise power is conveniently represented as an equivalent…
Tsys = Trx + Tant Where: Tsys = total system noise temperatureTrx = receiver noise temperatureTant = antenna temperature (everything seen by the antenna) Expanded form: Tsys = Trx +…
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