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Why use RF equipment if running transmission line? Just send audio frequencies down regular telephone/speaker wire. There is the Plain Old Telephone Service, you can still use regular old telephones and a battery. At 100 meters, you could just use hand signals or IR transmitters and skip the wire altogether. Even cave man magnetic radio is an option. Coax seems like an expensive way to create such a small closed-circuit audio network.

If you did connect multiple baofengs to a central junction via coax, the radios would overload each other. Directly paralleling them would be an expensive lesson, and just extending a little of the inner conductor into the junction would cause high SWR on the coax and still may be enough RF to damage the other radios. You would need to terminate each incoming radio line with a separate resistor of suitable power rating matching the coax impedance and each of those resistors should have some sort of shielding from the other incoming lines/resistors to control the amount of coupling between them. And even then, enough RF will probably leak out of the coax system to defeat the whole purpose anyhow. You are literally burning tens of watts of precious battery power in the field to accomplish the task of what should be a µW signal.

If you want to use the radios, you would be better off turning the power setting to low and investing in attenuators to lower the power that gets to your antenna, using only what power is necessary to make the contact limits who else hears it..

<blockquote data-quote="brandon7861" data-source="post: 834980" data-attributes="member: 53724">Why use RF equipment if running transmission line?&nbsp; Just send audio frequencies down regular telephone/speaker wire.&nbsp; There is the Plain Old Telephone Service, you can still use regular old telephones and a battery.&nbsp; At 100 meters, you could just use hand signals or IR transmitters and skip the wire altogether. Even cave man magnetic radio is an option.&nbsp; Coax seems like an expensive way to create such a small closed-circuit audio network.If you did connect multiple baofengs to a central junction via coax, the radios would overload each other.&nbsp; Directly paralleling them would be an expensive lesson, and just extending a little of the inner conductor into the junction would cause high SWR on the coax and still may be enough RF to damage the other radios.&nbsp; You would need to terminate each incoming radio line with a separate resistor of suitable power rating matching the coax impedance and each of those resistors should have some sort of shielding from the other incoming lines/resistors to control the amount of coupling between them. And even then, enough RF will probably leak out of the coax system to defeat the whole purpose anyhow. You are literally burning tens of watts of precious battery power in the field to accomplish the task of what should be a µW signal.If you want to use the radios, you would be better off turning the power setting to low and investing in attenuators to lower the power that gets to your antenna, using only what power is necessary to make the contact limits who else hears it..</blockquote>

[QUOTE="brandon7861, post: 834980, member: 53724"] Why use RF equipment if running transmission line? Just send audio frequencies down regular telephone/speaker wire. There is the Plain Old Telephone Service, you can still use regular old telephones and a battery. At 100 meters, you could just use hand signals or IR transmitters and skip the wire altogether. Even cave man magnetic radio is an option. Coax seems like an expensive way to create such a small closed-circuit audio network. If you did connect multiple baofengs to a central junction via coax, the radios would overload each other. Directly paralleling them would be an expensive lesson, and just extending a little of the inner conductor into the junction would cause high SWR on the coax and still may be enough RF to damage the other radios. You would need to terminate each incoming radio line with a separate resistor of suitable power rating matching the coax impedance and each of those resistors should have some sort of shielding from the other incoming lines/resistors to control the amount of coupling between them. And even then, enough RF will probably leak out of the coax system to defeat the whole purpose anyhow. You are literally burning tens of watts of precious battery power in the field to accomplish the task of what should be a µW signal. If you want to use the radios, you would be better off turning the power setting to low and investing in attenuators to lower the power that gets to your antenna, using only what power is necessary to make the contact limits who else hears it.. [/QUOTE]

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