Question T7A11
From subelement T7 - T7A
Where is an RF preamplifier installed?
Why is this correct?
An RF preamplifier is installed between the antenna and receiver (A) because it must amplify weak incoming signals before they reach the receiver. Installing it close to the antenna minimizes signal loss from feed line. Options B and C involve transmitter circuits where preamplifiers aren't used. Option D places it after the receiver, which would be useless since the RF signal has already been processed and converted to audio.
Memory tip
Remember the signal flow: antenna → preamplifier → receiver. Preamplifiers work on the 'receive side' of your station, not the transmit side. If you see 'preamplifier' in a question, think 'before the receiver' - the prefix 'pre' literally means 'before.'
Learn more
RF preamplifiers improve receiver sensitivity by boosting weak signals before feed line losses occur. In practical operation, they're essential for weak-signal VHF/UHF work like EME (moonbounce) or meteor scatter communications. The closer to the antenna, the better - many hams mount preamplifiers at the antenna itself using weatherproof enclosures, with DC power sent up the coax through bias tees.
Think about it
Why do you think installing a preamplifier at the receiver end of a long feed line would be less effective than installing it near the antenna?