Sun Fire
Low noise, high gain voltage (signal) amplifier (preamplifier).
I call it "Sun Fire' because "Star Fire" was already used when I built the companion piece which is a power inserter or a so-called "bias tee." Okay, so what do the Sun Fire do? Well, here's what it do -- read 'bout this thing, below.
Closeups of the controls
1. It amplifies the very weak signal sent down the coax to the receiver, in the shack, from the feed horn-mounted LNA. Its gain is variable from 0.0 dB (unity) to + 17 dB. It, tipically "sees' a signal level of -55 to -60 dBm (on a 75 Ohm line) (or "dBu") if the LNA is shut down or about
-43 dBu when the LNA is on. Gain is controlled by the "gain" control ... clever, huh?
It also has a "sensitivity" control to prevent front end overload.
2. It must be very low noise: Between .8 and 1.8 dB, which ain't super low noise but a darn sight better than a standard broadband preamp.
3. It matches impedance with a VSWR range of about 5:1 although with a properly designed system, that shouldn't be a concern.
4. It has a calibrated meter for direct level indication or relarive gain.
5. It incorporates a piezo buzzer for field use which changes pitch when the dish is moved across a target source: satellite, planet, constellation, etc.
6. The "meter preamp" switch bypasses the unit so that gain and sensitivity adjustments can be left at their preset positions when the unit is not required/desired.
7. The "DC Feed" switch interrups the diplexed power insertion supplied by the companion unit, "Star Fire." This allows for level, sensitivity and gain comparisons of the entire antenna system.
8. The "light" switch turns the meter lights on or off ... just like those things on every wall of my house.
The "Twins." Top is the "Sun Fire" preamp and bottom is the "Star Fire" power inserter.
See the companion unit: "Star Fire"
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