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Prodding the button on the left should give you a site map. I'd be interested in knowing how well it works and what you think of it.
Coaxial cables are used for all antenna connections. There are three types in common usage and they are listed in the table below. Cable losses (the
amount of signal lost in the cable) are significant at the frequency of 1800MHz used by Orange (Remember many Radars work at lower frequencies than this - never mind phones.). To reduce cable losses cable
runs should always be kept as short as possible. When installing coaxial cable you should remember than its characteristics depend upon its shape - so don't do anything to bend it sharply or to squash it.
Each area of damage introduces reflections in the signal and reduce the efficiency of the cable. Typically RG58 type cables have a minimum bending radius of about 3cm. In the table below cable losses are
described as High, Medium, or Low at 1800MHz. A detailed chart of cable characteristics is |
Cable Type |
Comments |
RG58 |
Standard cable found on most antennas. Medium Loss at 1800MHz. This cable (or physically similar) is commonly used on thin ethernet installations and terminations can be fitted using standard crimping tools for Group 1 cables. |
Allgon Low Loss (LL58) |
Replacement for RG58 found on all new Allgon antennae and now used by us for all RG58 leads. Low Loss. |
RG174 |
Thin cable used for adapter leads to phone bases and on the Minimag to allow it to fit around door seals. High Loss. |
UR 76 |
Alternative to RG58, fractionally lower loss. |
Cable attenuation table The table below has been taken from a number of (sometimes contradictory)
sources and should be read as a guide rather than a product specification. That said I don't think its far out. |
Attenuation dB/metre |
|||
Frequency |
450MHz |
900MHz |
1800MHz |
RG174 |
0.7 |
1 |
1.5 |
Allgon LL598 |
0.33 |
0.49 |
0.73 |
Allgon Low Loss (RG59 form factor) |
0.23 |
0.35 |
0.54 |
RG213 |
0.15 |
0.22 |
0.37 |
RG58 |
0.35 |
0.5 |
1.1 |
The Allgon LL58 cable has quite a useful reduction in loss over standard RG58 at 1800 MHz. Although the Allgon Low Loss cable offers further improvement over LL58 unfortunately in practise it is quite a difficult cable to use as it is thicker than RG58 (approximately the dimensions of RG59) and finding terminating plugs to fit it is problematical. |
Connectors
Most phones have a number of connectors for data, power and antenna. The connections on a Nokia 2110 series are shown below, others are similar except that the Ericssons and newer Nokias have the antenna connector on the back of the case near the antenna. The Nokia 3210 has no external antenna connector.
We have connectors for the antenna and data sockets for the Nokia, antenna connectors for the Ericsson 100 and 500 and can make cables to order.
Nokia 2110 base plug and antenna adapter Shown left and above (both
with one cover removed) this has a 0.8m length of RG174 cable terminated in a male FME connector. As it is it is an antenna adapter similar to the Orange one but cheaper and with better strain relief at the FME end. It
can also be used to give access to the multipin connector although the cable strain relief would need to be removed (slots out) to allow the extra cable through.
(Above) Nokia 9000/Communicator connector (left) and 61xx series (right)
Close-up of the Nokia 9000/Communicator series plug (above)
The FME connector (left) is frequently used in mobile phone installations primarily because it is quite slim and hence easy to thread through bits of car bodywork. Its RF performance is quite good.
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