The W3UJ Station Reference

Include Receiver Protection from the Start

Station Reference

The station-development guide explains how the station grew; the station tour introduces its operating roles. The reference below brings the radios, SDR receivers, RF hardware, accessories, software, and drivers together in one place.

Radio, Antenna, and SDR Switching Parts & Links

All radio-selection, antenna-selection, SDR switching, and PTT-combining parts are grouped here. Choose by function; these devices are not interchangeable.

These functions work together. Manual switches select the RF path. PTT-controlled hardware protects the SDR receiving path during transmission. Grounding, bonding, and surge measures serve additional purposes. Manual switching and grounded unused ports complement PTT-controlled protection; they do not replace it.

Understand Manual RF Selection → · Understand PTT and Receiver Protection →

SDR Switch testing: Test Your SDR Switch — N2EME’s five-step procedure → Includes the downloadable SDRSwitch.com RXin/RXout continuity checklist.

Software & Drivers

Operating software, CAT-control tools, timing utilities & required device drivers

Start with the Current SDR Console Installation Method

For a new installation: use PC Setup — Install and Identify One SDR Receiver. That is the main installation sequence. Get the model-specific official downloads from Software & Drivers.

The earlier SDRplay procedure below is retained as a version-specific station reference. DLL replacement is not a routine first step; use the developer’s instructions for your actual release and keep a working installation intact.

That sequence includes installing compatible SDRplay support, optionally testing the receiver in SDRconnect or the discontinued-but-still-downloadable SDRuno, closing the test application, and creating the SDRplay V3 Radio Definition in SDR Console. A compatible standalone API installation is also an accepted route.

SDRplay RSPduo & RSPdx-R2 — SDR Console Installation and Troubleshooting

Open the Earlier SDRplay Installation and Troubleshooting Notes

Official downloads: SDRplay API / drivers | SDR Console / RSPdx-R2 DLL | Omni-Rig | SDRuno final installer

1. Close SDR software. Download and install the current compatible Windows SDRplay API.
2. Connect the RSPduo or RSPdx-R2 using USB and verify that Windows recognizes it.
3. Install SDR Console and open Select Radio → Definitions → Search.
4. Choose SDRplay (API Version 3), where offered. Select the discovered receiver, add/save its Radio Definition, select it and start reception.
5. Verify reception before setting up optional transceiver CAT tracking.

The RSPduo uses the standard SDRplay API; do not assume simultaneous dual-tuner operation is supported. The RSPdx-R2 needs a compatible SDR Console version.

1. Download and install Omni-Rig from Afreet Software.
2. Choose the correct transceiver (for example, FT-991A or FTDX10), CAT COM port and radio-compatible baud rate, data bits, parity, stop bits and flow control.
3. Test communication, then configure SDR Console's External Radio feature to use the supported Omni-Rig connection.

Important: Omni-Rig controls a transceiver, not the SDRplay receiver. It is not required for SDR reception or device discovery. Avoid competing programs opening the same physical COM port.

1. Check the USB cable, Windows recognition, SDRplay API and SDR Console compatibility first.
2. Download the official SDRuno final release. Although discontinued, SDRuno can provide an independent receiver test.
3. Close SDR Console, install SDRuno, launch it and test whether it detects and receives signals from the RSPduo or RSPdx-R2.
4. Close SDRuno completely, then restart SDR Console.
5. Open Select Radio → Definitions → Search → SDRplay (API Version 3) (labels may vary). Select the receiver, add/save the definition and start it.
6. If neither program detects the device, troubleshoot the SDRplay API, USB connection and Windows device recognition.

Important: Installing SDRuno does not automatically create an SDR Console Radio Definition or guarantee a driver repair.

Some older compatible SDR Console installations require the SDRPlay RSPdx-R2 — May 22, 2024 support ZIP on the official SDR Console download page. It contains SDRSourceSDRplayV3.dll.

1. In SDR Console, open Tools → Files → Installation to find the installation folder.
2. Close SDR Console and back up the existing DLL.
3. Only if applicable to your version, extract the ZIP and replace the DLL following the developer's instructions.
4. Restart SDR Console, search for the RSPdx-R2 and create its definition.

Do not overwrite a newer working DLL with an older file. This DLL is not the SDRplay API driver and is not normally required for the RSPduo.

Educational reference graphic

Where Does the SDRplay Connection Fail?

Work down the checks in order. Change only one thing at a time. Test with the transmitter disabled and do not bypass RF/PTT receiver protection to troubleshoot USB or software.

Software compatibility: Record the SDR Console version, SDRplay API version, Windows version and receiver model before replacing files. For older installations, follow the developer's specific RSPdx-R2 DLL instructions only when applicable; do not replace a newer working DLL. SDRplay API/service issues and USB driver issues are not necessarily the same problem.

RSPduo note: A successful device connection does not prove that two tuners can be used simultaneously in your chosen SDR Console mode. Verify supported operating modes and bandwidth separately. Continue to PC Troubleshooting →

Recommended order: SDRplay API → Windows USB detection → SDR Console Radio Definition → receive test → optional Omni-Rig CAT control. Receiver discovery, CAT synchronization and RF/PTT protection are separate functions.

Follow the Signal Flow

Learn to trace the station one path at a time. RF, CAT/control, PTT/keying, USB/data, and power each perform different jobs and may follow completely different routes through the station. A complicated system becomes much easier to understand and troubleshoot when you stop looking at it as one large collection of cables and instead follow each path from beginning to end.

Keep the Right Things Separate

Sharing an antenna system, computer, or SDR architecture does not mean every circuit should be directly connected. Recognize where RF-path selection and separation, PTT/keying electrical isolation, and SDR receiver protection are required. Proper separation is part of the station design, not something to consider only after a problem appears.

Know What Each Component Does

Before adding a component, know why it is there and what problem it is intended to solve. A coax switch, splitter, PTT combiner, SDR Switch, SDR receiver, power supply, and transceiver each perform different jobs. Knowing the role of each component also helps prevent one device from being expected to provide a function or protection it was never designed to provide.

Protect the Receive System

Receiver protection should be designed into the station from the beginning. Know what happens when the transceiver is keyed, how the SDR receive path is removed or protected during transmission, and how that protection is controlled. Before transmitting into a newly assembled configuration, verify that the protection system actually changes to its transmit/protection state.

Separate the RF Path from the PTT Path

RF and PTT are different paths with different responsibilities. In the W3UJ station, the Daiwa CS-201A provides RF-path selection and separation, the DXE-3RIGKEYLINE provides PTT/keying combining and electrical isolation, and the SDR Switch provides transmit/receive switching and SDR receiver protection. Keeping those functions distinct makes the system easier to understand, operate, and troubleshoot.

Plan Before You Expand

Adding another SDR receiver is not the same as adding another transceiver. An additional SDR primarily expands the receive and signal-distribution side of the station. A second transceiver introduces another RF path and another PTT/keying source that must be incorporated into the existing switching and protection architecture.

Recognize the Tradeoffs

Every addition has consequences. A passive splitter makes receive-signal distribution easier but introduces path loss. Amplification may help compensate for loss, but it can also introduce overload or additional noise if used unnecessarily. More radios and receivers provide more capability, but they also create more signal paths, connections, and interactions to manage.

Draw It Before You Connect It

A station diagram is more than documentation. Drawing the system forces you to identify where RF travels, where PTT/control travels, where receiver protection occurs, how the computer communicates with the equipment, and where power is supplied. Problems are much easier to correct on a diagram than after the station has been wired.

Build • Verify • Expand

Start with the simplest configuration that accomplishes the goal. Make it work, verify each function, and learn what the system is doing before adding the next component. Building in stages makes troubleshooting easier and turns expansion into a deliberate process rather than simply adding more equipment.

Sign the W3UJ Visitor Log

Thanks for visiting. I hope the station photographs, diagrams, and operating notes help with your own radio projects.

If something on the page helped with your station, you’re building an SDR setup of your own, or you’d simply like to say hello, I’d enjoy hearing from you. Select the “Web” tab at the top of my QRZ page to sign the W3UJ Visitor Log.

Until then, I hope to catch you on the bands!

73, W3UJ — W3UJ

Related Operating and Build References

• Windows setup
• Troubleshooting

Software and Driver Links

Open the Software & Drivers directory for the SDR programs, device-support packages, CAT tools, and timing utilities referenced in these instructions.