#af gain

[circuitboard-blog]

Eddystone 750

[tymkrs]

27.Ham Button Attack III! Ham lesson o' de day

Back to the buttons!  But this time they're on the receiver.

AF Gain or Volume: This is pretty obvious - it sets the speaker or headphone listening level.

RF Gain: This is near the AF gain button and it adjusts the sensitivity of the receiver to incoming signals.

Attenuators: These are used to reduce the strength of signals at the receiving input.  They're used when excessively strong signals overload the receiver. 

Using the RF gain and attenuator controls can remove a lot of distortion when the band is full of strong signals.

Receiver incremental tuning: This is a fine tuning control used for SSB or CW operation which allows the operator to adjust the receiver frequency without changing the transmitter frequency.  This allows you to tune into a station that is slightly off frequency or to adjust the pitch of an operator's voice that seems to high or too low.  This can sometimes be called a clarifier.

Receivers also usually have a way to indicate signal strength, such as a meter with a moving needle or a variable-length bar at the side or bottom of the display.  The meter shows signal strength in S-units and a change of one S-unit is about a factor of 4 in signal strength.  S-units are numbered from S1 to S9 with S9 being the strongest.  The strength of signals stronger than S9 is reported as the number of dB greater than S9.  For example - "Your signal is 20db over S9!"

Next post I'll go into a few of the receiver's circuits that help to fine tune what it's receiving.

@atdiy/@tymkrs