Adjustable Receiver Audio Filter · 可调接收音频滤波器

27CHAPTER

可调接收音频滤波器

Adjustable Receiver Audio Filter
本章要点：除了 IF 侧的滤波手段之外，FTX-1 还在 AF（音频）级提供了可调接收音频滤波器，可对音频低端和高端分别独立裁剪。本章说明 LCUT / HCUT 频率与斜率的设置方法、按模式分别保存的默认值，以及与接收音质（AF TREBLE / MIDDLE TONE / BASS GAIN）调整之间的区别和配合使用方式。

27.1 可调接收音频滤波器Adjustable Receiver Audio Filter

EN

The FTX-1 incorporates an adjustable receiver audio filter, that affords precision control of the lower and upper audio ranges independently.

  1. Press and hold the [FUNC] knob.
  2. Select [CW SETTING] for CW mode and [RADIO SETTING] for other modes.
  3. Select the Mode and Menu Item you want to set (see table below).
  4. Rotate the [FUNC] knob, or touch "<" or ">" on either side of the value to adjust the receiver audio response as desired.
  5. Press the [FUNC] knob, or wait for about 3 seconds to save the setting.
  6. Press the [BACK] key several times to return to normal operation.

FTX-1 内置可调接收音频滤波器，可对音频的低端和高端范围分别进行精确控制。

  1. 按住 [FUNC] 旋钮。
  2. CW 模式选择 [CW SETTING]，其他模式选择 [RADIO SETTING]。
  3. 选择要设置的模式和菜单项（见下表）。
  4. 旋转 [FUNC] 旋钮，或触摸数值两侧的 "<" / ">"，按需调整接收音频响应。
  5. 按 [FUNC] 旋钮，或等待约 3 秒保存设置。
  6. 按几次 [BACK] 键返回正常操作。
表 27-1 可调接收音频滤波器菜单项与默认值Table 27-1 Adjustable receiver audio filter menu items and defaults
菜单组Menu group 模式Mode 菜单项Menu item 可选值Available values 默认值Default
RADIO SETTINGSSBLCUT FREQOFF / 100 Hz – 1000 Hz（50 Hz 步进）100 Hz
LCUT SLOPE6 dB/oct / 18 dB/oct6 dB/oct
HCUT FREQ700 Hz – 4000 Hz（50 Hz 步进）/ OFF3000 Hz
HCUT SLOPE6 dB/oct / 18 dB/oct6 dB/oct
RADIO SETTINGAMLCUT FREQOFF / 100 Hz – 1000 Hz（50 Hz 步进）OFF
LCUT SLOPE6 dB/oct / 18 dB/oct6 dB/oct
HCUT FREQ700 Hz – 4000 Hz（50 Hz 步进）/ OFFOFF
HCUT SLOPE6 dB/oct / 18 dB/oct6 dB/oct
RADIO SETTINGFMLCUT FREQOFF / 100 Hz – 1000 Hz（50 Hz 步进）300 Hz
LCUT SLOPE6 dB/oct / 18 dB/oct18 dB/oct
HCUT FREQ700 Hz – 4000 Hz（50 Hz 步进）/ OFF3000 Hz
HCUT SLOPE6 dB/oct / 18 dB/oct18 dB/oct
RADIO SETTINGDATALCUT FREQOFF / 100 Hz – 1000 Hz（50 Hz 步进）100 Hz
LCUT SLOPE6 dB/oct / 18 dB/oct18 dB/oct
HCUT FREQ700 Hz – 4000 Hz（50 Hz 步进）/ OFF3200 Hz
HCUT SLOPE6 dB/oct / 18 dB/oct18 dB/oct
RADIO SETTINGRTTYLCUT FREQOFF / 100 Hz – 1000 Hz（50 Hz 步进）300 Hz
LCUT SLOPE6 dB/oct / 18 dB/oct18 dB/oct
HCUT FREQ700 Hz – 4000 Hz（50 Hz 步进）/ OFF3000 Hz
HCUT SLOPE6 dB/oct / 18 dB/oct18 dB/oct
CW SETTINGCWLCUT FREQOFF / 100 Hz – 1000 Hz（50 Hz 步进）250 Hz
LCUT SLOPE6 dB/oct / 18 dB/oct18 dB/oct
HCUT FREQ700 Hz – 4000 Hz（50 Hz 步进）/ OFF1200 Hz
HCUT SLOPE6 dB/oct / 18 dB/oct18 dB/oct
EN

The filter settings are stored separately for each operating mode (SSB, AM, FM, DATA, RTTY and CW), so a narrow setting used for CW copying will not affect the wide setting used for FM.

各滤波设置按工作模式分别保存（SSB、AM、FM、DATA、RTTY 与 CW 各自独立），因此 CW 抄收时使用的窄带设置不会影响 FM 使用的宽带设置。

HAM 实战 · LCUT / HCUT 的实战用法FIELD NOTE AF 级的 LCUT / HCUT 是在音频上再裁一刀，和 IF 侧的 CONTOUR、NOTCH、DNF 作用位置不同，可以叠加使用（社区经验）：
① SSB 拥挤频段：把 LCUT FREQ 提到 300 Hz 左右、SLOPE 用 18 dB/oct，可以明显压掉邻台的隆隆声和低频噪声；弱信号 DX 时则降回 100 Hz 保留更多语音能量。
② SSB Contest 抄收：HCUT FREQ 收到 2400 Hz 附近能削掉高端嘶声，代价是声音发闷，需要在"听得清"与"听得舒服"之间取舍。
③ CW：默认 LCUT 250 Hz / HCUT 1200 Hz 已经是很舒服的窗口，遇到极拥挤时收窄到 100 Hz 步进细调即可，不必一开始就动 slope。
④ AM/FM 广播监听或本地中继守听：这一组默认较宽（AM 默认 LCUT OFF / HCUT OFF），想提升语音可懂度再加 LCUT 300 Hz 即可。
注意 slope 选 18 dB/oct 时截止更陡，但容易在截止点附近产生"闷罐感"，弱信号下推荐 6 dB/oct。 The AF LCUT/HCUT filters work at a different stage from the IF CONTOUR, NOTCH and DNF functions and can be combined with them (community-reported). Raise LCUT to about 300 Hz with 18 dB/oct on crowded SSB bands, and return to 100 Hz for weak-signal DX. Narrow HCUT for contest copying at the cost of a muffled sound. The 18 dB/oct slope cuts harder but can sound boxy; 6 dB/oct is gentler for weak signals.

27.2 接收音质调整Change the Sound Quality of the Received Audio

EN

You can change each of the high, mid, and low frequencies of the received audio to your liking. It can be set for each mode.

  1. Press and hold the [FUNC] knob.
  2. Select [CW SETTING] for CW mode and [RADIO SETTING] for other modes.
  3. Select the Mode and Menu Item you want to set (see table below).
  4. Rotate the [FUNC] knob, or touch "<" or ">" on either side of the value to adjust the receiver audio response as desired.
  5. Press the [FUNC] knob, or wait for about 3 seconds to save the setting.
  6. Press the [BACK] key several times to return to normal operation.

可以按自己的喜好分别调整接收音频的高音、中音和低音。可按每个模式分别设置。

  1. 按住 [FUNC] 旋钮。
  2. CW 模式选择 [CW SETTING]，其他模式选择 [RADIO SETTING]。
  3. 选择要设置的模式和菜单项（见下表）。
  4. 旋转 [FUNC] 旋钮，或触摸数值两侧的 "<" / ">"，按需调整接收音频响应。
  5. 按 [FUNC] 旋钮，或等待约 3 秒保存设置。
  6. 按几次 [BACK] 键返回正常操作。
表 27-2 接收音质调整菜单项Table 27-2 Received audio sound quality menu items
菜单组Menu group 适用模式Mode 菜单项Menu item 可选值Available values 默认值Default
RADIO SETTINGSSB / AM / FM / DATA / RTTYAF TREBLE GAIN高音范围设置-20 – 100
AF MIDDLE TONE GAIN中音范围设置-20 – 100
AF BASS GAIN低音范围设置-20 – 100
CW SETTINGCWAF TREBLE GAIN高音范围设置-20 – 100
AF MIDDLE TONE GAIN中音范围设置-20 – 100
AF BASS GAIN低音范围设置-20 – 100
技术提示 / TIP LCUT / HCUT 是"裁掉"（滤波），AF TREBLE / MIDDLE TONE / BASS GAIN 是"增减"（音调），两者是不同层的东西，别混为一谈：想去掉某个频段的干扰用 LCUT / HCUT，想让整体声音更亮或更厚用 AF 三项 GAIN。默认全部为 0，建议先单独调滤波器，音质 GAIN 保持 0，等确认滤波器已到合适位置后再做音色微调。 LCUT/HCUT are cut-off filters, while AF TREBLE / MIDDLE TONE / BASS GAIN are tone controls. Use the filters to remove interference and the tone controls to shape the overall sound. All three AF gains default to 0.