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The Sierra Radio Systems SIR-331 is a four port remote coax relay module for the Sierra Station Controller range.
Also known as the CX-1, this module can be used to switch one radio between four antennas, or one antenna between four radios. It is intended for HF and 6m operation, covering 1-60MHz, and provides a flexible RF switching option for remote HF stations, contest stations, repeater sites, receive systems, and automated shack installations.
The SIR-331 uses latching relays, so the selected port remains in its last state even if power is removed from the module. It also uses break-before-make switching, releasing the current connection before making the new one, while the built-in firmware prevents two relays from being active at the same time.
The module can be controlled through the Sierra DCN, or Device Control Network, and also provides momentary pull-to-ground inputs for external pushbutton or electronic port selection.
Key Features
- Four port HF and 6m coax relay module
- Also known as the CX-1
- Switches 1 radio to 4 antennas or 1 antenna to 4 radios
- Intended frequency range of 1-60MHz
- Suitable for 160m through 6m operation
- Maximum power handling of 100W
- Insertion loss less than 0.05dB on HF
- Port isolation typically between 53dB and 65dB across the HF band
- BNC RF connectors
- Latching relay design
- Retains last selected position if power is removed
- Break-before-make switching
- Firmware prevents multiple relays being active at the same time
- Control over Sierra DCN
- Manual control possible using external momentary pushbuttons
- Multiple modules can be used together for larger switching arrangements
Typical Uses
- Switching one HF radio between up to four antennas
- Switching one antenna between up to four radios
- Remote HF station antenna selection
- Contest station RF switching
- Automated shack antenna switching
- Receive antenna selection
- Repeater or remote site RF path switching
- Expanding a Sierra Station Controller installation
Station Controller System Role
The SIR-331 adds RF coax switching to a Sierra Station Controller system.
It connects to the Sierra DCN, using RJ45 style connections and network-style patch cables. The DCN connection is used for module communication and system power distribution between compatible Sierra modules.
Although the connectors are RJ45 style, the DCN ports are not standard Ethernet ports and should only be connected to compatible Sierra Station Controller modules and accessories.
Switching Arrangement
| Mode | Description |
|---|---|
| 1 radio to 4 antennas | Select one of up to four connected antennas for a single radio |
| 1 antenna to 4 radios | Select one of up to four connected radios for a single antenna |
| Disconnected state | All relays may be placed into a disconnected state |
| Expanded switching | Multiple SIR-331 modules may be used together for larger switching systems |
Specifications
| Specification | Details |
| Brand | Sierra Radio Systems |
| Model | SIR-331 |
| Product type | Four port HF and 6m coax relay module |
| Alternative name | CX-1 |
| Switching format | Single pole, four position |
| RF ports | 4 |
| Frequency range | 1-60MHz |
| Typical coverage | 160m to 6m |
| Maximum power | 100W |
| Insertion loss | Less than 0.05dB on HF |
| Port isolation | 53-65dB across the HF band |
| RF connector type | BNC |
| Relay type | Latching |
| Control method | Sierra DCN or external momentary pushbuttons |
| System type | Sierra Station Controller |
Important Note
This listing is for the SIR-331 Four Port HF and 6m Coax Relay Module only.
SIR-310 host adapter, installation kit, DCN hub, coaxial cables, antennas, radios, power supply, pushbuttons, control wiring, and other accessories are not included unless stated otherwise.
The SIR-331 is rated for a maximum of 100W. Please ensure it is suitable for your station power level before installation.
The Sierra DCN uses RJ45 connectors and network-style cables, but DCN connections are not standard Ethernet connections. Do not connect DCN ports directly to normal Ethernet network equipment.
A suitable 10-18V DC supply is required when the module is not being powered through a Sierra DCN connection from the SIR-310 host adaptor.
Shipping:
We have several shipping options for our products, including next-day and Saturday/Sunday delivery for certain items. Please see these options at checkout.
Returns:
If you have any equipment that needs to be returned to Martin Lynch & Sons, please fill out the form below:
Upon receipt of goods you have 14 days to return goods however the goods must be returned in original packaging and care must have been taken with the goods you wish to return. Under distance selling regulations you are not entitled to any refund on carriage charges or modification charges made at your request. Large items cannot be returned if they have been assembled, unless faulty.
Warranty Terms and Conditions
Outside of the 14 faulty return period, returned items cannot be accepted, unless covered by manufacturer's warranty. We will repair as much as possible on site however in exceptional circumstances products may have to be returned to the manufacturer of distributor.
For repairs/replacements under manufacturer’s warranty for any item please download a ML&S return form from the link above and return to ML&S with the faulty product.
International Warranty information
Warranty service for items we sell is available in the U.K. only, unless otherwise noted. It is your responsibility to pay freight for returned items to the U.K. and back to you for desired warranty coverage. All of our NEW products come with a minimum 12 month warranty, (Yaesu & Icom 24 months), with up to 90 days on second-hand equipment. Items returned for service must state "returned goods for repair" on the return air waybill or U.K. import customs duties apply and will be added to your invoice. For more info about returning items please contact our customer help desk, [email protected]