Heros Technology Ltd- SCR Preselector page

The SCR Preselector-CAT is suitable to work with SDR or analogue radios. It is inserted between the antenna and your receiver or transceiver providing
filtering of R.F.spectrum to reduce broadband energy and conforming signals before they reach the receiver, rejection of the MW AM broadcast band and VHF
FM broadcast band, removing strong emissions radiated back to the antenna from quadrature mixers and attenuating signals in the VHF region that could mix
with the sampling frequency of the analog to digital data converter in SDR radios.

The SCR Preselector-CAT can be operated in Stand-alone mode, from a personal computer, via USB or from a radio or digital system supporting I2C bus data communication. The software application runs on PC under Windows 2K, XP, Vista and Windows 7 (32 & 64bits) OS.

Five operating modes:

Stand-alone mode: by means of its control knobs.

Remote operating modes:

- CAT serial protocol over Virtual Com Port (VCP)
Kenwood TS-2000 compatible protocol.

- Graphic User Interface (GUI) on PC.

- Over the Internet or Local Network. TCP/IP protocol.

- I2C bus from an external radio or digital system.

CAT remote control. Tracking feature.

CAT (Computer Aided Transceiver), serial data communication protocol over Virtual Com Port (VCP) enables the SCR Preselector-CAT to provide the user with
a way to interface with several radios. The microcontroller on board translates valid CAT commands into specific instructions.
The user can operate the preselector from dedicated radio software such as Power SDR, DDUtil, HamRadio de Luxe, SDR Console, HDSDR, SDRMAX, etc., radio Logging programs, N1MM and others, CAT utilities like CSP Manager, OmniRig and SDRMAXCAT, among others.

Technical features:

■ Six selectable bands and preselector By-Pass.

■ Five Tuneable Band Pass Filter bank for HF Bands covering 1.8 to 30 MHz plus 50MHz band BPF.

■ All passive L/C filters. No active switching or amplifier devices in the signal path, (LNA Off), therefore it does not contribute to IMD (Intermodulation Distortion).

■ Very high linearity (IP3). Suitable for Software Define Radios and analogue receivers.

■ PTT feature enables connecting in-line with a 100Watts transceiver allowing to by-pass the preselector in transmission.(with Dual By-Pass relay accessory).

■ Two antenna inputs,one antenna output, let insert a converter, filter, etc between antenna and Preselector.

■ 0dB, 6dB, 12dB, 18dB input attenuator using MiniCircuits PAT series dedicated attenuation cells.

■ Embedded -110dB stop band Broadcast Band Rejection Filter. (AKA BCB filter, Brick Wall filter, MW band killer filter).

■ Six Band Pass Filters.

■ Tuning coils wound on large toroid cores T-106 size, rated for 100Watts RF applications, avoiding saturation in front of large signals.

■ Band Pass Filters have Notch filters centered on the adjacent amateur bands given an exceptional stop-band attenuation.

■ Digital tuning. Nine bits variable digital capacitor. One pF resolution. (Variable capacitor emulator).

■ Two embedded 7th order, 60MHz, Elliptic Low Pas Filter for FM broadcast band rejection and sampling frequency attenuation.

■ Switchable low noise amplifier (LNA). Gain 25dB, IP3 38dB, Noise figure 2.7dB.

■ 12V DC/1Amp DC max. output connector for an external 150 Watts RF rating Input/Output by-pass dual power relay. (PTT or Keying line activated).

■ Power supply: 12Volts DC/ 0.5Amp max. 2.5mm plug power connector.

■ Dimension: 220mm x 165mm x 52mm (8.661 x 6.496 x 2.047in).

■ Weight: 1.5Kg.

USB

■ Full speed USB v2.0 compliant.
■ Plug and Play feature.
■ USB type B connector.
■ ESD protection on USB lines.
■ Optocoupled USB sense signal.
■ Optional USB Galvanic Isolator available.

I2C bus

■ I2C bus external lines Galvanically isolated(ADuM1251).
■ 8 bits standard I2C serial bus interface.
■ Supports 100Kbits/s and 400kbits/s FAST I2C Bus protocol.
■ Mini Din connector for I2C control lines.
■ Compatible with most microcontrollers.

IMPORTANT: If the preselector is connected in line with a transceiver, take precautions to prevent transmitting through it. An Input/Output by-pass dual power RF relay accessory is available to by-pass the preselector in transmision switch-over.

NOTE: Some FlexRadio models include RF by-pass power relay. See primary antenna ports configuration section on specific FlexRadio Owner Manual for connection options.

The SCR Preselector in QEX magazine.
The first version of SCR Preselector is featured in May/June 2008 issue.
(Reprinted with permission © ARRL)

SCR Preselector-CAT user manual

Operating modes.

Stand alone mode.

Because the dynamic environment in which you operate demands that you exercise the most effective command possible, the SCR Preselector-CAT is designed with the most important functions immediately available for adjustment so control knobs and pushbuttons are reduced to minimum possible.
Two knobs/push-buttons together a dynamic LCD display is located on the front panel for total operation.
The large flywheel-tuning knob with finger hole is the main tuning control. Pushing it lives actual screen and enters the main menu.
On its left hand, a second knob features menu navigation and selection.
A combined operation of rotating and pushing knobs lets shift and select all available functions.

CAT remote operation mode. Tracking feature.

CAT (Computer Aided Transceiver), serial data communication protocol over Virtual Com Port (VCP) enables SCR Preselector-CAT to provide the user with a way to interface with several radios. The user can operate from remote control software such as Power SDR, DDUtil, HamRadio de Luxe, SDR Console, HDSDR, SDRMAX, etc., radio Logging programs, N1MM and others, CAT utilities like CSP Manager, OmniRig and SDRMAX-CAT among others.
Refer to your specific radio software application manual regarding CAT operation.
The microcontroller on board translates valid Kenwood TS-2000 compatible CAT commands and reacts properly.

Starting in CAT remote control mode.

NOTE: The preselector GUI application must be closed before interfacing the preselector with any radio software.
Power-On the preselector and plug the USB cable, a virtual COM port opens on PC; start and configure your application to track the preselector from your radio software..

CAT configuration example on two popular radio software, PowerSDR and HamRadio Deluxe.

Graphic User Interface (GUI) on PC remote operation mode.

The GUI on PC lets to the operator to command the SCR Preselector-CAT in the same way as it does in stand-alone mode. In addition it provides options and utilities.

Working in CAT mode with dedicated radio software the preselector GUI application is not used.

The application runs under Windows 2000, XP, Vista and Windows 7 (32 & 64 bits) OS.

Graphic User Interface.on PC.

Context menu .
See User manual for details.

Internet/Local network remote operation mode.

The SCR Preselector-CAT supports connections via the Internet and Local network.To make use of this feature execute the GUI application software on your computer and on a remote one.The protocol only uses TCP/IP; UDP which by definition is unreliable is not used.

Remote server (preselector side)
To start the communication open first the Remote Server.
The connection console is displayed showing the address in dotted format of the computer where the server is running and the port number.
Click on Start button. If the connection is successful you will start to receive commands from the client computer, current commands are traced on the console. The SCR Preselector-CAT will respond in accordace with valid CAT commands.

Remote Client (remote control side)

To connect to the server make sure the server is started and is listening. Open the Remote Client.
The connection console is displayed showing the default address in dotted format of the host computer and the port number, default port 51000.
Enter the Host IP address in the text window and start operating the SCR Preselector-CAT application.
Executed commands on the GUI are traced on the console. Also valid CAT commands can be send from the text box.

I2C bus remote operation mode.

SCR Preselector-CAT features remote control mode from an external radio or digital system supporting I2C bus data communication system.
It operates totally independent of other remote control modes.
I2C lines are Galvanically isolated by means of ADuM1251 a hot swappable digital isolator specialised device from Analog Devices Inc.

In order to switch to I2C remote control mode first program the I2C addresses on GUI application, Context menu, I2C slave’s address.
Next go to LCD main menu, Functions selection knob (2), and pick “3. I2C Mode”. The preselector remains on that remote control mode until other control mode is selected.

For more details regarding I2C bus remote operation mode see User manual.

Optional accessories

General Purpose Dual By-Pass relay

150 Watts RF power rating

It is designed to by-pass the Input and Output RF ports of any device in line with your transceiver or transmitter.
A typical application includes inserting between antenna and a transceiver or transmitter a preselector, preamplifier or filter device.
On transmission switchover, via PTT or Keying line, the Input and Output RF ports of the device are by-passed avoiding being overloaded.
Switching configuration: default By-Passed.

Dual Antenna Relay page

	USB Galvanic Digital Isolator for SDR radios The USB Galvanic Digital Isolator for SDR radios is designed to break the galvanic connection between USB host PC and the attached SDR radio peripheral avoiding that whatever power and ground noise from the PC side do not influence the sensible radio on the other side. The resultant galvanic isolation improves common-mode voltage, prevents ground loops, a common cause of interference and data distortion issues, improves reception, as the noise floor in the receiver is lowered, and removes spikes and birdies on the PC panoramic screen. In addition provides isolation of 1000V AC between the host PC and the radio peripheral that guard against surges that may come from the antenna connected to the receiver. The USB Galvanic Digital Isolator for SDR radios is based on ADuM 4160 Full/Low Speed 5 kV USB Digital Isolator and ADuM 5000 Isolated DC-to-DC Converter both from Analog Devices combining high speed CMOS and chip-scale air transformer iCoupler technology. The USB Galvanic Digital Isolator complies with specifications USB 1.1, Low speed (1.5Mbit/s) and USB 2.0 Full Speed (12Mbit/s). The speed mode is set manually via two jumpers inside (default full speed). Most of the time it is not necessary change between modes but if automatic speed detection is desired, an external hub can be connected to the peripheral side configured for full speed. The USB Galvanic Digital Isolator is self powered from the host PC through the USB cable. An embedded DC/DC converter provides a galvanic isolated voltage of 5VDC/100mA to the peripheral side. It includes additionally ESD, EMC protection of the data lines and power transient short-circuit guard. It is highly advisable not to power any part of the connected radio from the USB bus, instead an external dedicated power supply must be used. The USB Galvanic Digital Isolator behaves like an USB cable, no USB drivers are needed. It works on all operating systems, Mac, Windows, Linux, etc . Features: Isolation 1.000 Volts AC Protection: EMC, ESD, Overvoltage Surge, Short-circuits. Power supply: - PC side: From USB cable, 5VDC. Attached signalling LED. - Drawn power from peripheral radio max: Through USB cable, 5V DC/100mA. USB modes: Full speed (12 MBit/S) Low speed (1.5 MBit/S). Switchable. Standard socket connectors: PC side: USB type B, peripheral side: USB type A. Dimensions 67 mm x 66 mm x 28 mm. (2.638x2.598x 1.102inch) USB2 pair of cables included.

PTT foot switch

Robust momentary action foot operated switch with non slip base.

• 1.8m cable length.
• Standard 3.5mm jack plug. Other connectors available, Please ask.
• Dimensions 74 x 75 x 32mm
• Rated 3A 250V AC

	SCR Preselector-CAT
	Including: CD with installable Software package, USB driver and Manual. Set of connection cables and high speed USB cable included.	£ 576.00

	150 Watts dual relay for antenna by-pass Including set of cables .	£ 110.00

	USB Galvanic Digital Isolator for SDR radios (USB2 pair of cables included	£ 75.00

	PTT foot switch	£ 15.00

	Order

SCR Preselector-CAT

SCR Preselector-CAT

Copyright MMIII by Heros Technology Ltd. Webmaster

For any comments regarding this website, please e-mail us.