- Lossy transmission line between your antenna and 10 GHz transverter.
- 10 GHz transceiver with a poor noise figure (that can't be fixed).
- EME operation with low background noise where every fraction of a dB counts.
Commercial receive pre-amplifier sources:
|Kuhne MKU LNA 101AS|
Surplus receive pre-amplifier Source - Modified KU band LNA's
- K0AWU - Bill uses a surplus KuBand LNA to provide about a 1db NF and 20db gain to overcome superflex cable loss on the receive path from his tower to shack.
Potential Benefits of Receive Pre-amplifiers:
- Overcome receive path losses from transmission lines, adapters, relays, connectors, etc.
- Optimize the transmit path without concern for the receive path, if a choice is necessary.
- Improve your station's noise figure to compensate for a poor or remote transverter.
- Must be connected directly to a low-loss antenna relay for maximum benefit.
- The potential for severe overload from other stations nearby and/or on adjacent frequencies dictate that you reduce the gain in the receive path down stream of the receive pre-amplifier. A lower gain receive pre-amplifer (single stage, >12 dB) may be better than a higher gain unit (dual stage, >22 dB), depending on your station configuration.
- Pre-amplifiers must be well protected from any RF power using relays with high isolation.
- Proper sequencing becomes more important to insure that protection relay(s) have completed switching before any RF power is applied.
- Never allow your antenna relay to be switched during a transmission!
- Filtered DC voltage is necessary to avoid injecting power supply noise.
- Unterminated receive pre-amplifiers can go into self oscillation.
- Pre-amplifiers are subject to potentially destructive RF transients from adjacent bands.
- Gain and can deteriorate over time so be sure to measure it while still in new condition.
- Rain, humidity and vibration can degrade your pre-amplifier electronics and/or connectors performance, over time.
Click here to return to Contents and Navigation.