11 RF gain control

This control adjusts the gain of the receiver high- frequency amplifier section.

For normal receiver pe rformance, and maximum gain, this control should be in the full clockwise position. If you are having trouble copying the desired signal make a note of the stations peak S-meter reading. Then, adjust the RF control counterclockwise, so that the meter needle is stationary at this level. Now, all signals that were less than the desired signal will be attenuated, such as static noise, etc., making reception easier.

If the incoming signal pegs the S-meter you can also reduce the receiver gain by counterclockwise rotation of the RF control. The S-meter pointer will always advance up- scale as the RF control is rotated counterclockwise, as a visual reminder that the gain of the radio has been re- duced.

Simultaneous use of the RF gain control and AGC switch

If a strong signal (such as a local station) appears in the vicinity of the intended receive signal, the S-meter may show unusual deflection due to the AGC voltage developed from the strong disturbing signal. If this occurs, turn the RF gain control counterclockwise so the meter pointer remains at about the original deflection peak and turn the AGC switch to the FAST position. This will reduce the unwanted AGC voltage and permit clear reception.

12 AF gain control

Turn the knob to increase or decrease the volume. Clockwise rotation increases the volume and counterclockwise rotation decreases the volume.

13 RF ATT (Attenuator) switch

When the incoming receive signal is very strong, the signal should be attenuated to prevent distortion of the sig-

nal, thereby stabilizing the receiver performance. This is easily done by activating the RF ATT switch. This control is also useful when a strong signal is near your desired sig- nal; while some loss will occur to the desired signal, as well as the undesired signal, the use of the attenuator will sometimes allow you to understand what is being re- ceived. This switch allows attenuation of the input signal by 10, 20 or 30 dB. For normal receiver pe rformance, this switch should be in the 0 dB position.

Note:

When using the VC-20 VHF converter you might occasionally encounter carrier interference from Television or FM broadcast stations. If you encounter any unknown interference rotate the RF ATT switch to the 10 dB position. This will help to reduce any cross modulation that might occur due to the strength of these types of signals.

14 AGC switch

This switch selects the operating time constant of the AGC (Automatic Gain Control) circuit. When the AGC switch is set to SLOW, the receiver gain and S-meter readings will react slowly to large input changes, and when set to FAST, the receiver gain and S-meter will react quickly to changes in the input signal level.

The normal position when using all modes is the SLOW position. When working any of the following you might wish to use the FAST position.

•When tuning with the TUNING dial.

•When receiving weak signals.

•When a high-speed CW signal is being received.

Note:

This switch is disabled during FM operations.

© NOTCH switch

When the NOTCH switch is turned ON, the NOTCH control functions as a NOTCH filter (except in the CW mode). In the CW mode, the NOTCH control functions as an APF (Audio Peak Filter).

®NB 2 switch

Noise blanker 2 is used for long duration pulse noise, like the "woodpecker-. To reduce "woodpecker" radar noise interference, set switch NB 2 to the ON position (NB 2's effectiveness depends on the specific type of interfer- ence). If you use NB 2 for short duration pulse noise, the receive tone may become distorted, making it difficult to hear.

Unfortunately no noise blanker can remove all different types of interference, but the two noise blankers that have been provided in the R-5000 are effective in most cases.

If there is no "woodpecker" present, the switch should be in the OFF position.

Note:

NB2 is disabled during FM operations.

1] NB 1 switch

For pulse type noise, such as generated by automotive ignition systems, turn the NB 1 switch ON.

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