TV Coax Cables and Signal Loss

Three types of coax cable (RG-6, RG-11, RG-59) are used for connecting an antenna to televisions. These cables have a 75 ohm (Ω) impedance, use F-type male connectors, and have 1 to 4 layers of shielding. More shielding has better immunity from interference and is a little more durable, but is a little more expensive. The more shields the better, especially for outside cables.

RG-6 coax cable
This cable is the industry standard for home reception. and is available with 2, 3, or 4 layers of shielding. Four layer shielding should be used for outside cables.

RG-11 coax cable
This cable can be used if signal loss is a problem, typically a long cable run. The advantages are it has the least loss, and can also carry high power signals. The disadvantages are it's more expensive, less flexible, bigger and heavier. This cable is primarily designed for high power transmissions and long cable runs.

RG-59 coax cable
This cable can be used, but is a little more lossy and has only a single layer of shielding. It's usually used indoors for raw video signals (recorders, games, etc.). RG-59 was used for over-the-air, cable, and satellite TV before RG-6 became common.

Twin-lead cable
This cable is sometimes called flat or ribbon cable, and should be replaced with coax. Twin-lead works well for VHF frequencies (RF 2-13) and is especially good at the VHF-Lo channels (RF 2-6), but is not suitable for UHF channels (RF 14 and higher). Additionally it does not have any shielding.

SIGNAL LOSS

All cables have some signal loss that depends on cable type, length, and frequency (RF Channel). The longer the cable and the higher the frequency, the greater the loss. Radio frequency channels in the VHF band (RF 2-13) have noticeably less loss than RF channels in the UHF Band (RF 14 and above). Loss is measured in decibels (dB's).

Loss Depends on

Cable Type
Cable Length
Radio Frequency Band

TV Coax Cables
VHF / UHF (RF 2 - 36) 75 ohms (Ω) Impedance F-type male connectors
Coax Type	Loss dB / 100 ft	Shield Layers	Primary Use
RG-6	-5 dB	2, 3, or 4	TV Reception Industry Standard
RG-11	-3 dB	2, 3, or 4	High power signals or long cable runs
RG-59	≈ -6 dB	1	Raw Video or TV Reception

Loss dB / 100 ft	Primary Use
Twin-lead Cables
VHF (RF 2 - 13) 300 Ω Impedance Blade connectors
-1 dB ( VHF-Lo ) -4 dB ( VHF-Hi )	VHF Signals

Coax Cable Loss Calculator
Frequency Band:
Cable Type:
Cable Length:
Frequency Band Cable Length Cable Type Cable Loss -dB

SIGNAL SPLITTERS

A coax cable Signal Splitter is used to connect to multiple TV's and devices. A two port splitter cuts the signal in half, equivalent to adding about 70 feet of cable. The more the signal is split (output ports) the greater the signal reduction.

Output Ports	Loss per Port
2	-4 dB
3	-6 dB
4	-8 dB
8	-12 dB

Splitter and wall output ports that are not used should be terminated with a 75 ohm load or termination.

CONNECTORS

Two cables can be connected using a female-to-female connector, also called a barrel. Cable wall plates are barrel connectors. Ground Blocks are barrel connectors that can be grounded. Right angle connectors (female-to-male) can be useful connecting to televisions and antennas with limited space. All connectors introduce a small signal loss, about -0.5 dB.

TWIN-LEAD ADAPTERS

Some older antennas and televisions use a twin-lead connection and need an adapter to connect to a coax cable. A coax-to-twin-lead adapter (75/300 Ω) is an impedance MATCHING NETWORK (circuits) or a BALUN (ferrite transformer) that matches coax to twin-lead. Adapters are bi-directional, signals can go in both directions. An adapter will introduce a small signal loss that increases with frequency (RF Channel).

Frequency Band	RF Channel	Loss dB
VHF-Lo	02 - 06	-0.2
VHF-Hi	07 - 13	-0.4
UHF	14 - 36	-1.4

SYSTEM LOSS CALCULATOR

Estimate cabling loss from the antenna output port to a television based on cable type, frequency band, cable length, and the number and type of signal splitters, connectors and adapters.

Antenna-to-TV Signal Loss
Frequency Band:
Cable Type:
Cable Length:
Signal Splitters:	2 Ports , 3 Ports 4 Ports , 8 Ports
Connectors:	Ground Block, Barrels...
Adapters:	Twin-lead to Coax
Frequency Band / RF Channels Cable Loss Splitters Loss Connector Loss Adapter Loss SYSTEM LOSS (dB)