TOOLS FOR COMFORTABLE AND EFFECTIVE RECEPTION
AGC (AUTOMATIC GAIN CONTROL)
The AGC system is designed to help compensate for fading and other propagation effects, with characteristics that can be of particular value on each operating mode. The basic objective of AGC is to maintain a constant audio output level once a certain minimum threshold of signal strength is achieved.
Main Band (VFO-A) AGC Selection
Press the [AGC] button repeatedly to select the desired receiver-recovery time constant. You will observe theAGC status notation in the AGC column of the Receiver Configuration Indicator on the display, denoting the AGC receiver -recovery time currently in use. For most operation, we recommend the “AUTO” mode. Additionally, you may disable the AGC by pressing and holding in the [AGC] button for two seconds.
Sub Band (VFO-B) AGC Selection
1.Press the [B] button.
2.Within five seconds of pressing the [B] button (while the imbedded orange LED is blinking), press the [AGC] button repeatedly to select the desired receiver-recov- ery time constant. You will observe the AGC notation below the Sub frequency on the display, denoting the Sub receiver’s currentAGC receiver-recovery time. For most operation, we recommend the “AUTO” mode. Additionally, you may disable the AGC by pressing and holding in the [AGC] button for two seconds.
NOTE:
Pressing the [AGC] button allows selection of the desired receiver-recovery time constant. Normally, the “AUTO” selection is satisfactory for most situations, but in the event of operation on a crowded band where you wish to receive a weak signal, you may wish to change the setting (to FAST, for example). The “AUTO” mode selections are:
OPERATING MODE | AUTO AGC SELECTION |
LSB | SLOW |
USB | SLOW |
CW | FAST |
AM | FAST |
FM | FAST |
RTTY | SLOW |
PKT (FM) | FAST |
PKT (LSB) | SLOW |
ADVICE:
If the AGC receiver-recovery time is set to “Off” by pressing and holding in the [AGC] button, the S-meter will no longer deflect. Additionally, you will likely encounter distortion on stronger signals, as the IF amplifiers and the following stages are probably being overloaded.
QUICK POINT
Several aspects of AGC performance may be configured via the Menu. However, because AGC can have such a profound impact on overall receiver performance, we generally do not recommend any changes to the AGC Menu selections until you are thoroughly familiar with the performance of the FT-2000.
TERMINOLOGY:
Automatic Gain Control, or AGC, is a circuit that senses the incoming signal strength, and then limits the gains of the RF and IF stages so as to keep the output audio volume at a more-or-less constant level. AGC also protects the RF, IF, Audio, and DSP stages from overload, as it limits the signal strength that is allowed to flow, irrespective of the input signal level.
Page 62 | FT-2000 OPERATING MANUAL |
