Sometimes you just cant put up a full size antenna on the outside of your property and the best option is to install some type of indoor CB antenna.
Even though the antenna is inside it doesn’t mean that it cannot be effective if you take certain things into consideration and a few simple installation tips.
For an antenna to function properly at CB frequencies it needs to be full wave length or fractions of the full wave length, for example full wave is just under 40 feet and half wave is about 18 feet. Having the antenna lengths set like this allows the CB to operate efficiently with little resistance from the antenna and giving the best possible flow of transmission power.
The Difference Between Visible and Hidden Antenna Length
A 1/4 wave CB antenna for vehicles will typically have a 5 foot metal “whip” mounted onto a coiled wire base, as the actual 1/4 wave length for CB radio is approx 9 foot the coiled wire will be 4 foot long.
5 foot whip + 4 foot coiled wire = 9 foot (1/4 wave length)
Any coiled length of the antenna is still registered by the CB in an electrical sense but will never radiate radio waves as effectively as the straight bit of the antenna but is needed to make things function smoothly.
This is the ultimate drawback of CB antennas when you have limited space to put them in making mobile CB antennas a good compromise for setting up indoors.
Antenna Height Is Key To Performance
Even though signals on the CB bands do have the potential for long range communication, most of them still work on the line of sight principle. This means your going to get much better reception from an antenna placed on the top floor of your building (or in the loft) than the ground floor.
If this involves adding some extra coax to make things work then this will be a better option, provided the coax length doesn’t start running beyond the 100 foot margin.
Loss of Signal Through Coax
For every foot of Coax between the back of your CB and the base of the antenna there will be a certain amount of signal loss. This loss can be minimized by trimming the coax to the exact length so coils of it are not left hanging around after you have installed your antenna.
Try to invest in some good quality low loss coax, it may cost a bit more but your whole CB setup will thank you for it.
Please note that the coax you use for the television and other domestic video equipment is completely different from CB coax and at best will leave you wondering why no one can hear you and at worst could cause permanent damage to your CB.
Room to Breathe
When placing your antenna in your house or loft make sure there is a clear space around it and it is straight. An antenna that has a bow in it will still work but as most CB radios operate on vertical antenna systems it will not be as effective.
Metal sheeting on the roof or walls will basically reduce any incoming and outgoing CB signals so taking a good look at where you are placing the antenna could save you the time and trouble of having to move it again (some buildings use metal rods in the walls to improve structural strength).
Also nearby large metal object have been known to cause problems with CB signals.
Taking the time to optimize an indoor CB antenna system will pay off in the long run.