Advanced Menu Overview (RT 880)

SPI Deferral

This setting defines the delay, in seconds, that the radio waits after a user action before saving changes to flash memory. Delaying writes helps extend the life of the flash storage.

• Warning Indicator: While changes are pending, a red warning triangle appears on the display.

• Important: Do not power off the radio while the warning triangle is visible. Either wait for the deferral period to expire or use the Shut Down menu option to safely save changes.

Tone Monitor Time

Specifies the duration, in seconds, that the CTCSS/DCS tone indicator remains visible on the display after the received signal is lost.

AM AGC Fix

Activates an additional level of automatic gain control (AGC) for strong AM signals, helping to prevent receiver overload and saturation.

• Note: The effect is not immediate. Very strong AM signals may produce a brief buzz or crackle before the AGC adjustment takes full effect.

Noise Gate

When enabled, the Noise Gate mutes the speaker if external noise exceeds the Noise Ceiling setting in the Squelch menu, even when squelch is forced open (via squelch override or a Squelch setting of 0).

• Purpose: Designed for use with very weak signals to reduce background noise.

AF Filters

Selects the audio filter combination for the receiver. Three filters are available: High Pass, Low Pass, and De-emphasis. Any combination of these filters can be applied.

• FSK Mode: An additional setting designed for digital operation, such as APRS.

DTMF Deviation

Adjusts the volume of transmitted DTMF tones.

• Note: The TX Deviation setting also affects DTMF volume. Both settings should be adjusted together for optimal results.

Repeater Tone

Sets the frequency (in Hz) of the single-burst repeater tone that is transmitted when the key assigned to send the repeater tone is pressed. The default frequency is 1750 Hz.

TX Deviation

Adjusts the amount of FM deviation during transmission, effectively controlling the bandwidth of your signal. The default value is 64. Values above 74 may cause distortion that is noticeable to listeners.

Subtone Deviation

Adjusts the level of CTCSS/DCS subtone transmission. Setting the level too high may make the tones audible during normal transmission.

• Note: The TX Deviation setting also affects subtone volume. For optimal results, adjust both TX Deviation and Subtone Deviation together.

AM Hack Transform
AM Hack Displacement
(ALPHA 19+)

Fine tunes the AM TX "Hack".
AM TX is not even close to perfect, it's experimental and results will likely vary dramatically from user to user. These setting are designed to be experimented with by users such that good default values can be discovered.

• Displacement: Adjusts the apparent volume or gain of the simulated modulation.

• Transform: Adjusts the amount of offset applied to a simulated AM transmission.