Rene Schmidt, DF9GR, develops and manufactures a series of Easy-Rotor-Control (ERC) interfaces designed to connect antenna rotators to a computer. The devices are available in the e-shop at schmidt-alba.de/eshopThe entire range consists of several variants designed for different types of rotators and different operating scenarios – from a single azimuth axis to a combination Azimut/Elevácia pre satelitnú prevádzku a EME.
The heart of each ERC is a microprocessor that transmits information about the current azimuth (or elevation) to the computer and at the same time translates instructions from the computer to switch the relays controlling the rotator motor. Communication with the computer is carried out using standard DCU-1, GS-232A or GS-232B protocols, which guarantees compatibility with virtually all logging, contest and tracking programs without the need for special drivers.
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ERC Version 4 – universal azimuth interface
ERC Version 4 is a compact single-axis azimuth interface with relay outputs and USB or RS-232 communication port. The key feature is the compact format of the board - the ERC can be built directly into the original rotator controller box, as the motor control relays are part of the board itself and no external relay is required. The interface has been verified with all popular logging and contest programs.
| Variant | PC interface | Price (including VAT) |
|---|---|---|
| ERC VERSION 4 SMD, USB – installed and tested | USB | 109.00 EUR |
| ERC VERSION 4, USB Kit | USB | 85.00 EUR |
| ERC VERSION 4, RS232 Kit | RS-232 | 76.00 EUR |
All three variants are shipped within 2–3 business days.
ERC-M – single-axis or dual-axis interface for azimuth, elevation and DUAL-azimuth
ERC-M is a modular interface capable of controlling one or two rotators simultaneously. It supports three configurations: single azimuth, combined azimuth and elevation (for satellites and EME) and DUAL-azimuth (for example, two horizontal yagis at 90° for optimal coverage). The interface communicates with a computer via USB, optionally also RS-232. The outputs are open-collector, which allows the connection of rotators with external motor power. Rotorcard is an optional expansion board designed for direct integration into the rotator cabinet; one ERC-M central board can serve a combination of any rotators, including home-made designs.
| Item | Description | Price (including VAT) |
|---|---|---|
| ERC-M SMD – installed and tested | USB + optional RS-232; 1 or 2 axes | from 99.00 EUR |
| ERC-M USB Kit – construction kit | USB; 1 or 2 axes | 69.00 EUR |
| Rotorcard Kit for ERC-M | Expansion board for 1 Rotator | 27.00 EUR |
| LAN option Kit for ERC-M | Expansion with LAN interface | 79.00 EUR |
| Slimline-case Kit for ERC-M | Slim chassis 83×78×25 mm | 21.00 EUR |
| Desktop-housing AZ/EL Kit (black aluminum) | Desktop chassis with LCD, LED and buttons; 128×140×41 mm | 79.00 EUR |
| Desktop-housing AZ/EL Kit (silver aluminum) | Desktop chassis with LCD, LED and buttons; 128×140×41 mm | 75.00 EUR |
| Cable DIN8 to D-SUB15 for Kenpro/Yaesu KR/G-5×00 | For connecting the rotator to the ERC-M | 21.00 EUR |
The optional LAN interface for the ERC-M allows remote control over a local network without the need for a direct USB connection to the operating computer.
ERC-DUO – special interface for Yaesu DXA/DXC and G/KR-5×00
The ERC-DUO is designed for operators with Yaesu DXA/DXC series rotators (azimuth) or Yaesu/Kenpro G/KR-5×00 (azimuth and elevation). It features a USB interface, open-collector outputs and a 4-step speed controller. Unlike the ERC Version 4, the ERC-DUO has a direct Mini-DIN6 connector compatible with the DXA/DXC series - a cable is included. For the G/KR-5×00 rotators, an optional DIN8 to DIN8 cable is required.
| Item | Description | Price (including VAT) |
|---|---|---|
| ERC-DUO | Interface for Yaesu DXA/DXC and G/KR-5×00; USB; open-collector outputs; 4-stage speed controller | 119.00 EUR |
| Cable DIN8 to DIN8 for Kenpro/Yaesu KR/G-5×00 | Optional cable for G/KR-5×00 rotators | 19.90 EUR |
| ERC-DUO SDX adapter | Adapter for connecting SDX series Yaesu/Kenpro to ERC-DUO | 9.90 EUR |
ERC-Mini – historical predecessor replaced by ERC-DUO
The ERC-Mini DX and ERC-Mini SDX were previous models designed for Yaesu DXA/DXC and SDX series rotators. Both variants are currently not available and have been replaced by the ERC-DUO. Operators looking for a replacement for their existing ERC-Mini should upgrade to the ERC-DUO, which covers the same rotators and adds a 4-step speed controller and open-collector outputs.
Cables and connectors
ERC-Shop offers a full range of ready-made cables and loose connectors needed for installation. For home designers and operators who make the cable themselves, loose connectors and shielded cable are available.
| Item | Use | Price (including VAT) |
|---|---|---|
| 6-pin Mini-DIN cable with free end | Kenpro/yaesu KR/G-xxxx DXA/DXC | 4.90 EUR |
| 8-pin DIN cable with free end | Emotator EV-800DX, Kenpro/yaesu KR/G-5×00, Orion OR-2300 | 13.90 EUR |
| DIN8 to D-SUB15 cable | Kenpro/Yaesu KR/G-5×00 and ERC-M | 21.00 EUR |
| DIN8 to DIN8 cable | Kenpro/Yaesu KR/G-5×00 and ERC-DUO | 19.90 EUR |
| Mini-DIN6 to Mini-DIN6 cable | Yaesu DXA/DXC on Yaesu radio | 9.90 EUR |
| 8-pin DIN connector (free) | Emotator EV-800DX, Kenpro/yaesu KR/G-5×00, Orion OR-2300 | 3.00 EUR |
| 6-pin DIN connector (free) | Create RC5A-3-P / RC5B-3-P / ERC5A-P | 3.00 EUR |
| 5-pin DIN connector (free) | Emotator with 5-pin remote connector | 3.00 EUR |
| 8-pin flat connector (free) | Kenpro/yaesu KR/G-xxxx SDX | 3.00 EUR |
| 8-core shielded cable with free ends | 8× 0.14 mm², for custom configuration | 2.00 EUR |
| RS-232 cable for ERC-M SMD | For ERC-M SMD V2.4 and later | 10.00 EUR |
Installation and calibration
Assembling the ERC kit is not difficult and in the case of the ERC Version 4 Kit it will take approximately two hours. It is especially important to pay attention to the correct polarity of electrolytic capacitors, diodes and ICs. The more difficult part is the installation in a specific rotator - a separate document with more than 40 pages is dedicated to this, where the connection to most commercial rotators is described in detail and illustrated, including Yaesu, CDE/Hy Gain, Kenpro, Emotator, Orion, Create and others.
Final calibration is done via the supplied software, where the rotator properties are defined and the sensor voltage is assigned to a specific azimuth. Calibration after 30 degrees guarantees high rotation accuracy. Most ERC interfaces require an external supply voltage of 10 to 15 V - this must be taken into account when installing in the rotator box.
Compatible software
ERC rozhrania boli overené so širokým spektrom programov: DF9GR vlastný obslužný softvér (súčasť dodávky), PSTRotator od YO3DMU (lite verzia na CD, plná verzia komerčná), N1MM Logger Rotor, HamRadio Deluxe, WinRotator, Hamscope, WSJT, DK7ZB Rotor a ďalšie. Kompletný zoznam je dostupný v Software Guide na stránke ERC-Shop.
Videos
The first video demonstrates controlling the Yaesu G650C rotator from the N1MM Rotor program via the ERC RS-232 interface:
The second video shows the ERC USB kit version installed with the Yaesu G-1000DXC rotator:
User ratings and experiences
ERC interfaces have eHam.net hundreds of reviews with a long-term high average score. On CQ.SK bola publikovaná podrobná skúsenosť s dvoma kusy ERC zabudovanými do rotátorov Yaesu a CDE (Hy Gain).
The authors highlight several recurring positives. The ERC works correctly the first time it is turned on without the need for further tuning after successful installation and calibration. Customer support from DF9GR is very helpful and fast. The package from Germany arrives within a week as standard. Documentation, including a 40-page installation manual, is available on CD upon order; all parts in the kit are carefully sorted in bags.
GU0SUP (in practice with ERC and Yaesu rotator) states that calibration is simple and intuitive. He strongly emphasizes one step: after setting up and calibrating in the DF9GR software, it is essential to press the WRITE ERC button, otherwise the settings will not be saved in the interface memory. He also appreciates the antenna's "parking position" function - an azimuth to which the antenna automatically returns after the session ends.
"ERC is suitable for a moderately skilled constructor, but it is a very useful addition that every radio amateur will appreciate." - CQ.SK
The ERC user discussion group is available at groups.io/g/easy-rotor-control.