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Call 0345 2300 599The Sierra Radio Systems SIR-421 is a 6ft LMR195 coaxial cable assembly designed for use with Sierra Station Controller RF switching modules and compatible amateur radio equipment.
This cable is fitted with a BNC connector on one end and a PL-259 connector on the other, making it ideal for connecting Sierra coax relay modules with BNC RF ports to HF radios or station equipment using standard SO-239 antenna sockets.
The SIR-421 is a useful accessory for the SIR-331 Four Port HF and 6m Coax Relay Module, allowing the BNC-equipped relay module to be connected cleanly to a transceiver, receiver, antenna input, or other HF station equipment with a PL-259 style connection.
Key Features
- 6ft LMR195 coaxial cable assembly
- BNC connector on one end
- PL-259 connector on the other end
- Suitable for use with Sierra Station Controller RF switching modules
- Ideal accessory for the SIR-331 Four Port HF and 6m Coax Relay Module
- Useful for connecting BNC-equipped RF modules to radios with SO-239 sockets
- LMR195 cable construction
- Passive cable assembly with no power required
- Suitable for tidy station wiring and remote switching installations
Typical Uses
- Connecting an SIR-331 coax relay module to an HF radio
- Connecting BNC RF switching modules to PL-259 station equipment
- Short LMR195 station patch lead for remote antenna switching systems
- Shack automation installations
- Remote HF station wiring
- Contest station RF switching layouts
- General BNC to PL-259 RF interconnection
Specifications
| Specification | Details |
|---|---|
| Brand | Sierra Radio Systems |
| Model | SIR-421 |
| Product type | Coaxial cable assembly |
| Cable type | LMR195 |
| Length | 6ft |
| Connector 1 | BNC |
| Connector 2 | PL-259 |
| Power requirement | None |
| Typical use | Connecting Sierra BNC RF modules to HF radio equipment |
Compatible Sierra Station Controller Products
The SIR-421 is especially suited for use with the SIR-331 Four Port HF and 6m Coax Relay Module, which uses BNC RF connectors.
Important Note
This listing is for the SIR-421 6ft LMR195 coax cable only.
SIR-331 coax relay module, radios, antennas, antenna switches, adaptors, and other accessories are not included unless stated otherwise.
Please ensure that the connector types, cable length, frequency range, and power level are suitable for your installation before ordering.
Shipping & Delivery
We offer UK and international delivery services, including next working day and selected weekend options for eligible orders. Available services, prices and estimated delivery times are displayed at checkout.
Delivery Information
Delivery options depend on the parcel's size, weight, contents and destination. Express and weekend services are subject to availability and cut-off times. Oversized or exceptionally heavy items may require a specialist delivery quotation.
Returns & Cancellations
To arrange a return, please contact ML&S or complete our returns form. You may also exercise your statutory right to cancel by email or another clear statement, without completing the form.
Changed Your Mind?
Under the Consumer Contracts Regulations 2013, most purchases made online or by telephone can be cancelled within 14 days of receipt.
You must notify us of your cancellation within this period and return the goods within a further 14 days.
Please handle all goods with care. Returned items must be in a resaleable condition, complete with their original packaging, and all supplied accessories.
You may inspect goods as you would in a shop. Handling beyond what is necessary to inspect them may result in a lawful deduction for diminished value.
Exceptions
Modified Equipment & Reversal Charges
Additional return conditions may apply to equipment modified at the customer's request, including wideband transmit or receive modifications.
ML&S may charge a reasonable fee to reverse physical modifications and restore the equipment to its original factory specification. Any such charge will be agreed in advance and deducted from your refund.
Custom-Made Cable Assemblies
Coaxial cable assemblies manufactured to a customer's specifications are excluded from the 14-day return policy and are non-refundable unless faulty.
Software & Labour Charges
Labour and modification charges requested by the customer are non-refundable once the work has been completed.
Computer software may only be returned under the 14-day return policy if it remains sealed and unopened.
Return Postage Charges
Customers are responsible for the direct cost of returning unwanted or incorrectly ordered goods, where permitted by law. You may arrange your own suitable return postage or use one of our optional prepaid services.
Standard Parcels
Royal Mail Return Label
£5.95
Per parcel
For eligible standard-sized parcels, subject to Royal Mail restrictions. Free collection included.
Larger Parcels
DPD Return Label
£7.95
Per parcel
For larger or heavier parcels and any shipments with batteries.
Collection Service
DPD Collection
£25.00
Per parcel
Available upon request for eligible addresses, subject to availability.
Prepaid return charges will be confirmed before booking and deducted from your refund.
These prices apply to eligible UK mainland returns. Oversized items, specialist products and returns from other destinations may require a separate quotation. Estimated return costs will be disclosed before purchase.
Faulty or Incorrectly Supplied Goods
Return postage charges do not apply to faulty, damaged or incorrectly supplied goods returned under statutory rights. ML&S will arrange a free return in these circumstances.
Refunds
Refunds are processed without undue delay following receipt and inspection of returned goods, and no later than 14 days after we receive goods returned under statutory cancellation rights.
Refunds will be issued to the original payment method. Any prepaid return postage charges or lawful deductions for diminished value will be itemised.
Warranty Terms & Conditions
New Equipment Warranty
Minimum 2-Year Warranty
All new products supplied by ML&S carry a minimum two-year warranty against manufacturing defects, excluding batteries, which are covered by separate warranty terms.
Some manufacturers provide extended warranties, such as the three-year warranty available on eligible Yaesu equipment. Any additional coverage is subject to the manufacturer's terms and conditions.
Our workshop may assess and repair faulty equipment on site or refer it to the manufacturer or an authorised service centre where necessary.
Warranty exclusions may include batteries, normal wear and tear, accidental damage, misuse and unauthorised modifications, as specified in the applicable warranty terms.
All warranties are provided in addition to your statutory consumer rights against ML&S, which are not limited by the warranty period.
International Returns & Warranty
Unless otherwise stated, ML&S warranty servicing is carried out in the UK. International customers must contact us before returning goods to confirm shipping and customs requirements.
International customers are responsible for return postage unless the goods are faulty and ML&S has been notified within a reasonable time.
ML&S accepts no responsibility for additional charges resulting from incorrectly completed customs documentation. Any additional duties charged to ML&S as a result will be billed to the customer before return of the goods.
Need Help With a Return?
Our team can assist with returns, postage arrangements, modifications and warranty claims.
Nothing in these terms excludes or limits your statutory consumer rights.

