Option 1 for HE 310: 24-fold switch SW 024.

The SW 024 cluster switch can be used to switch up to 24 RF upstream signals. Thus, for example, a measured ingress interferer can be uniquely assigned to the cluster from which it comes. This greatly facilitates the search for the source of interference in the upstream frequency range

Furthermore, a CATV signal up to 1,218 MHz can be connected to input DS-IN on the front of the device (e. g. output signal of the head-end). Thus, the RF switch SW 024 can also switch between downstream and return path measurement.

KWS-Electronic 24-fold switch SW 024

The UMS system automatically ensures that a field device VAROS 107 displays the spectrum or the measurement results of exactly the one switch input where it is physically connected to.

In addition to the selective mode, the sum signal of all 24 RF inputs can be generated and monitored from a spectrum point of view.

Specifications RF switch SW 024:

Frequency range

USIN,i [i = 1…24]: 5–85 MHz
USOUT: 4.38–85 MHz
DSIN: 45–1,218 MHz


24 × USIN: F Socket/75 Ω  (IEC 60169-24)
1 × DSIN: F Socket/75 Ω  (IEC 60169-24)
1 × RFOUT: F Socket/75 Ω  (IEC 60169-24)
1 × USBIN: USB-B Jack; Protocol: KWS proprietary, not USB compliant

Upstream inputs

RF Level (nominal) – per Modem or Signaling Channel: 60–75 dBµV
RF Sum Level – per Upstream Input USIN,i: ≤ 90 dBµV

Transmission Loss – USIN,i → RFOUT: < 6.5 dB (up to 85 MHz)

Transmission Loss Sum Path – USIN,i → RFOUT: < 5.3 dB (up to 85 MHz)
Isolation – USIN,i → RFOUT: > 70 dB (up to 85 MHz)

Isolation – USIN,i → USIN,j: > 70 dB (up to 85 MHz)

Return Loss – USIN,i active: > 12 dB (up to 85 MHz)
Return Loss – USIN,i inactive: > 18 dB (up to 85 MHz)
External Voltage: < 70 Veff (DC/50 Hz)

Downstream input

Level (nominal) – per TV channel: ≤ 120 dBµV

Transmission Loss – DSIN → RFOUT
< 1.0 dB (up to 868 MHz)
< 1.1 dB (up to 1,002 MHz)
< 1.2 dB (up to 1,218 MHz)

Return Loss – DSIN activ
> 12 dB (up to 868 MHz)
> 12 dB (up to 1,002 MHz)
> 12 dB (up to 1,218 MHz)

Isolation – DSIN inactiv → RFOUT
> 75 dB (up to 204 MHz)
> 60 dB (up to 868 MHz)
> 56 dB (up to 1,002 MHz)
> 52 dB (up to 1,218 MHz)

RF Sum Power – DSIN: < 500 mW
External Voltage: < 70 Veff (DC/50 Hz)

RF output

Return Loss
> 12 dB (USIN,i aktiv)
> 12 dB (DSIN aktiv)


Mixing of the signalization of the field units VAROS 107 in UMS measurement mode

Dual-Conversion Architecture
Input Frequency: 5–85 MHz
Intermediate Frequency (IF): 433.92 MHz
Target Frequency: 4.5 MHz
Mixer Bandwidth (−3 dB): 120 kHz


User Display: 26 × LED red / Power; USIN,1–USIN,24; DSIN

Power supply

Built-In primary Power Supply Unit

Mains connector: Plug in accordance with IEC-60320-C8
Mains Voltage: 100–120 VAC, 200–240 VAC, 50–60 Hz
Power consumption: max. 10 W

Environmental conditions

Operating Temperature: 0 °C to +45 °C
Storage Temperature: -10 °C to +55 °C
Humidity: 10 % to 90 % (non-condensing)

Electromagnetic compatibility

per EN 61326-1


per EN 61010-1


Width: 440 mm, Height: 44,45 mm, Depth: 275 mm (19″, 1 RU/without clamping angle)

Width: 483 mm, Height: 44,45 mm, Depth: 275 mm (19″, 1 RU/with clamping angle)


approx. 3.5 kg

Content of delivery

  • F patch cable (75 Ohm, to connect SW 024 to HE 310)

  • USB patch cable (USB-B → USB-A, to connect SW 024 to HE 310)

  • Power Cable

  • 2 pieces clamping angle for 19″ rack mounting

  • 8 pieces M4 × 8 mm crosshead screws

Option 2: The step to a high-end return path monitoring system – combination with field device VAROS 107.

The result: traditional AND quality measurements in the return channel.

1 VAROS 107 measurement possibilities

Cluster selektive:

  • Measurement of the frequency response in the return path (sweeping)

  • Comfortable adjustment of return path amplifiers (in-house and line)

  • Display of MER, BER, noise margin and constellation diagram of modulated test carriers in the return path

  • Automated measurements with protocol generation

  • Ranging to reference level (forced by headend device)

Sum signal and cluster selective:

  • Display of the received spectrum (in the headend) in real-time

  • Max-hold and waterfall diagram display

  • Registration and deregistration of field devices for exclusive measuring access (signaling via telemetry frequencies in return channel)

KWS-Electronic HE 310: Fieldunit VAROS 107
KWS-Electronic AMA 310/UMS: Illustration System

2 HE 310 with SW 024 (optional)

The SW 024 allows for an optional extension to up to 24 upstream clusters: switching of field devices on one cluster; creation of a sum signal out of all 24 clusters. Thus measurements can be performed cluster selective or with the sum signal.

  • Real-time spectrum of the return path range (5–65 MHz) as well as max-hold function

  • Measurement of modulated test carriers (transmitted by VAROS 107) in the upstream with MER, BER and constellation diagram

Interaction with VAROS 107

  • Bi-directional communication between HE 310 and VAROS 107 possible over the HFC network

HE 310: standalone mode usable as real-time spectrum analyzer with max-hold function (sum signal and cluster selective).


Hybrid Fiber Coax Network: Optical and coax cable distribution network for downstream and upstream from the headend to the subscriber.

4 Transfer of measurement data to …

the head-end equipment

  • as MPEG-2 data stream over Ethernet (UDP and RTP)

  • as MPEG-2 data stream over ASI

In the headend these data streams can be multiplexed in existing DVB-C channels as a separate data service.

KWS-Electronic HE 310: Realtime spectrum

Real-time spectrum analyzer:

The heart of the HE 310 is a real-time spectrum analyzer. Typical errors are reliably detected like e.g. an increased noise floor, short-term ingress interferers or a TILT in the upstream frequency range.

The MaxHold function in real-time guarantees for a detection of even shortest ingress events.

Also in the return channel: Quality is what counts.

In addition standard (and well know from the downstream) RF measurement parameters such as MER and BER or constellation diagram can be gathered and transmitted back to the field devices VAROS 107.

For this purpose test signals transmitted by the field devices are highly precisely measured by the HE 310.

KWS-Electronic HE 310: Return channel PRBS
KWS-Electronic HE 310: Amplifier line up

Never bevor amplifier line-up has been so easy.

No matter if attached to the house or a line amplifier – The line-up toolbox guides you through leveling and equalizing the return channel – safe and easy.

Still standard in the return channel: Wobbeling (frequency response measurement).

The frequency response measurement is done without affecting active modem connections. The zoom function helps when evaluating details.

KWS-Electronic HE 310: Wobbling
KWS-Electronic HE 310: Report

The protocol function is only one push of a button away:

One push of a button is enough to execute all measurements possible with the system and to store the results as a protocol in XML format. Also for the protocol generation no previous knowledge is necessary.

Some user editable control elements allow for a fast assignment of a protocol to the measurement location, a customer, a field technician, a measurement situation and so on.

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