Cable
RG400
End A
TNC FEMALE
End B
TNC FEMALE
Specs Summary
25 ft RG400 — TNC FEMALE to TNC FEMALE
RG400 cable assembly, 25 feet, with TNC FEMALE and TNC FEMALE connectors. Hand-assembled, tested, and ships free within the US.
25 ft — TNC FEMALE / TNC FEMALE
$88.98
Free shipping • In stock
Other lengths:
Signal Loss — 25 ft
Approximate insertion loss for this 25 ft RG400 assembly at common RF frequencies.
| Frequency | Loss / 100 ft | Loss — 25 ft |
|---|---|---|
| 100 MHz | 3.5 dB | 0.88 dB |
| 450 MHz | 7.8 dB | 1.95 dB |
| 900 MHz | 11.5 dB | 2.88 dB |
| 1.8 GHz | 17 dB | 4.25 dB |
| 2.4 GHz | 20 dB | 5 dB |
| 5.8 GHz | 34 dB | 8.5 dB |
About This Assembly
RG400 Cable
RG-400 is a double-shielded, silver-plated PTFE coaxial cable built to MIL-C-17 specifications with a 0.195" outer diameter. Its construction mirrors RG-142 but with two braid shields for even greater shielding effectiveness. The standard cable for military and avionics applications requiring certified materials and traceable performance.
TNC Connector
TNC (Threaded Neill–Concelman) is the threaded version of BNC, offering improved performance up to 11 GHz and better vibration resistance through its screw coupling. It is commonly used in mobile radio antennas, avionics, and outdoor installations where BNC's bayonet lock would not provide sufficient mechanical security.
Common Applications
This TNC cable assembly is well suited for military-spec RF interconnects and avionics signal routing. The combination of reliable TNC connectors and custom-cut cable length makes it a practical choice for both field installations and bench setups. Every assembly is hand-terminated, continuity tested, and ships free within the USA.
Frequently Asked Questions
Is this cable hand-assembled in the USA?
Yes. Every CoaxRF cable assembly is hand-terminated and continuity tested at our US facility before shipping. We do not drop-ship pre-made cables from overseas — each cable is built to order.
Can I order a different length than 25 ft?
Yes. This page is for the 25 ft assembly. Use the length buttons above to select a different standard length, or use the Cable Builder for any custom length.
How much signal loss will I see with this 25 ft cable?
At 1800 MHz, RG400 loses approximately 17 dB per 100 ft. This 25 ft assembly will have roughly 4.25 dB of insertion loss at that frequency. See the signal loss table for all frequency points.
What is the maximum frequency for this assembly?
This assembly is rated DC – 6 GHz. The effective frequency limit is set by the lowest-rated component — either the cable or one of the connectors. Both TNC FEMALE and TNC FEMALE connectors must be within spec at your target frequency.
What is your return policy?
We accept returns within 30 days of delivery. Custom-length cables are accepted as long as they are in original condition. Contact us and we will provide a prepaid return label at no charge.
