8 REJECTING INTERFERENCE

CHANGING RECEIVE BANDWIDTH

 

 

 

AUTO NOTCH (SSB)

 

 

(CW/FSK/FM)

 

 

 

 

 

Auto Notch automatically locates and attenuates

The width of the receive pass band can be changed

interfering tones within the receive pass band. This

function operates digitally at the IF level, hence it can

without altering the current receive frequency. Change

affect your S-meter reading, and may affect (slightly

the bandwidth by adjusting the LO/WIDTH control.

attenuate) your desired signal. If interfering tones are

When the control is adjusted, ÒWIDTHÓ and the newly

weak, you may find that Beat Cancel eliminates them

selected bandwidth appear on the Display.

more effectively. Also, Auto Notch may not notch out

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

signals inside the pass band if signals just outside the

 

 

 

 

 

 

 

 

pass band limits are stronger.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

After switching ON the function, selecting a mode other

 

 

AGC

AUTO

 

NB

 

 

 

 

 

than SSB will switch OFF the Auto Notch function (LED

 

 

 

 

 

 

WIDTH

 

 

 

 

 

 

 

 

goes out). Changing back to SSB re-activates the

 

 

CW

 

 

 

 

 

function automatically (LED lights). If strong, steady

 

 

 

 

 

 

 

 

interference is present, switching Menu No. 18 (TRACK)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

to OFF may improve the notching capability. To block

 

 

 

 

 

 

 

 

CW interference, switch TRACK to ON, then switch

 

CW

 

FSK

 

 

FM

TRACK to OFF to lock the adaptive filter.

 

Bandwidth

 

Bandwidth

 

Bandwidth

Interfering tone

 

 

 

(Hz)

 

(Hz)

 

 

(kHz)

Notch band

 

 

 

 

 

 

 

50

 

250

 

5

Receive pass

 

 

 

 

 

 

 

 

 

 

band

 

 

 

100

 

500

 

6

 

 

 

 

 

 

 

 

 

 

200

 

1000

 

8

 

 

 

 

 

400

 

1500

 

10

 

 

 

 

 

 

 

Press [AUTO NOTCH] to toggle the Auto Notch function

 

600

 

 

 

12

 

 

 

 

ON or OFF.

 

 

 

1000

 

 

 

14

¥ The LED indicator in the button lights when the

 

 

Default values

 

 

 

function is ON.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Note: The effect of Auto Notch may differ under different receiving

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

conditions even when using the same response time.

ADAPTIVE FILTERS

The Auto Notch, Beat Cancel, and Noise Reduction functions accomplish their design purposes by modifying the characteristics of adaptive filters. Adaptive filters adapt or change their characteristics according to the nature of the signal being received at a given moment. Menu No. 18 (TRACK) determines whether the adaptive filters are allowed to change in this manner or not.

It is also possible to specify how long the received signals will be monitored before determining filter characteristics. This monitor period is inversely proportional to the response time. The longer the monitor time, the slower the response time and vice versa. Use Menu No. 14 (LINE.ENH) to select a different Line Enhance response time, Menu No. 16 (SP.BEAT) for the Beat Cancel response time, and Menu No. 17 (SP.NOTCH) for the Auto Notch response time.

The adaptive filters may not function correctly with signals that have a poor signal-to-noise (S/N) ratio. Under poor conditions, you may find that optimum results are obtained by switching OFF the adaptive filters via Menu No. 18 (TRACK).

Note: Only Auto Notch, or Beat Cancel, or Noise Reduction can be used at one time. They cannot be activated at the same time. Also, Menu No. 18 changes to its default setting when the TS-870S power is switched OFF and then ON again.

BEAT CANCEL (SSB/AM)

Beat Cancel also attenuates unwanted tones within the pass band, but it is more capable than Auto Notch at removing low-level tones. Also, this function works at the AF level, therefore you will notice there is no S-meter signal loss, although the S/N ratio may be lowered in the AM mode.

After switching ON the function, selecting a mode other than SSB or AM will switch OFF the Beat Cancel function (LED goes out). Changing back to SSB or AM re-activates the function automatically (LED lights).

Interfering tones

Receive pass band

Receive pass band

Press [BEAT CANCEL] to toggle the Beat Cancel function ON or OFF.

¥The LED indicator in the button lights when the function is ON.

Note: The effect of Beat Cancel may differ under different receiving conditions even when using the same response time.

52

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Image 58
Kenwood TS-870S Rejecting Interference, Auto Notch SSB CW/FSK/FM, Adaptive Filters, Beat Cancel SSB/AM, KHz

TS-870S specifications

The Kenwood TS-870S is a distinguished transceiver that stands out in the world of amateur radio, particularly for enthusiasts who seek a blend of advanced technology and user-friendly features. Introduced in the early 1990s, this HF transceiver quickly gained a reputation for its exceptional performance, versatility, and reliability, making it a favorite among operators worldwide.

One of the most noteworthy features of the TS-870S is its direct-sampling technology, which allows for superior signal fidelity and processing. This technology enables the transceiver to operate across a range of 160 meters to 10 meters, catering to both casual and serious operators. Its high-performance 16-bit digital signal processing (DSP) facilitates effective noise reduction and filtering capabilities, enhancing the overall clarity during transmission and reception.

In terms of power, the TS-870S boasts an output of 100 watts, providing ample power for various communication needs. The transceiver is equipped with an automatic antenna tuner, which simplifies the task of matching the antenna to the operating frequency, ensuring optimal performance without the hassle of manual adjustments.

Another significant aspect of the Kenwood TS-870S is its user interface, featuring a large, easy-to-read display, and a logically arranged control layout. This makes it accessible for both novice and experienced operators. The built-in memories allow for quick storage and access to favorite frequencies and settings, enhancing operational efficiency.

The Kenwood TS-870S also includes various advanced features such as an optional 2.4 kHz and 6 kHz roofing filter which provides improved performance in crowded band conditions. The receiver's dual VFOs (Variable Frequency Oscillators) enable simultaneous monitoring of two frequencies, which is particularly useful for operators who need to keep track of multiple signals or engage in cross-band communication.

Apart from its technical specifications, the TS-870S is constructed with durability in mind, ensuring that it can withstand the rigors of frequent use. It supports various operating modes, including SSB, CW, AM, and FM, making it a versatile choice for diverse amateur radio activities.

In conclusion, the Kenwood TS-870S combines advanced technology with user-friendly characteristics, offering amateur radio operators an exceptional tool for communication. With its innovative features, robust performance, and flexibility, it continues to be a respected choice among radio enthusiasts, solidifying its legacy in the realm of amateur radio.