KE0TBT
Newbie
I'm wanting to connect up to eight ham radios to a single EFHW antenna. Has anyone built an 8-port switch or coupler?
73, KE0TBT
Lee Lichtenwalner
Russellville, AR
73, KE0TBT
Lee Lichtenwalner
Russellville, AR
For receive only or transmit?I'm wanting to connect up to eight ham radios to a single EFHW antenna. Has anyone built an 8-port switch or coupler?
73, KE0TBT
Lee Lichtenwalner
Russellville, AR
TransmitFor receive only or transmit?
For transmit you would want a switch not a coupler which would make the antenna common to all radios all the time. I see a lot of RF switches from MFJ and others up to 6 ports but you would have to do some research to find an 8 port.Transmit
With only two antennas and many receivers I needed to have some type of Multicoupler I could connect all the radios to so I didn't have to keep reaching behind radios and connecting/disconnecting antennas. I've had a copy of Phil Atchley's LF-HF Receiver Multicoupler for some time and decided it was time to build this Multicoupler.
Phils Multicoupler Page 1
Phil's Multicoupler Page 2
Today's transceivers are pretty robust and a brief transmission, especially in SSB mode should have no dire consequences. Plus if switched to no antenna you would have no receive which should get your attention that something is wrong.You'd better think long and hard about this thing, because one day you will transmit into nothing 'cos you've left the switch/patch panel or whatever in the wrong position with maybe dire consequences.
Maybe separate receive and transmit antennas and coaxial changeover relays driven from the PTT lines of each Tx.. An 8 way splitter plus amplifier could feed the 'normally closed' receive contact of the relay while the 'normally open' coaxial contact feeds the transmitter to the antenna. Coaxial relays aren't cheap.
Here's an article on a homebrew 8-port multicoupler...
I had a similar requirement, but for only four transceivers. It wasn't a EFHW, but it was still a multiband antenna. I had Ameritron RCS-4 on hand. While the RCS-4 is meant to connect one transceiver to four possible antennas, it can also be used in reverse. It worked quite well. Just a simple switch box on the desk to select any of the four transceivers. While a RCS-4 only works with four antennas/transceivers, there is also a RCS-10 which works with eight. A manual, with schematic, is available on-line. Both the RCS-4 and RCS-10 are pretty pricy.I'm wanting to connect up to eight ham radios to a single EFHW antenna. Has anyone built an 8-port switch or coupler?
Each radio would be operated separately, one at a time, anywhere from 160-6 meters.Are you planning on using all of the transmitters on the same frequency?
Thanks
Joel
Do you have photo's of what you built?I had a similar requirement, but for only four transceivers. It wasn't a EFHW, but it was still a multiband antenna. I had Ameritron RCS-4 on hand. While the RCS-4 is meant to connect one transceiver to four possible antennas, it can also be used in reverse. It worked quite well. Just a simple switch box on the desk to select any of the four transceivers. While a RCS-4 only works with four antennas/transceivers, there is also a RCS-10 which works with eight. A manual, with schematic, is available on-line. Both the RCS-4 and RCS-10 are pretty pricy.
But don't forget about the accessories. I built a separate switch box that allowed me to manually switch between several audio devices (speakers, audio filters, etc.) and Morse keys (keyers and manual). The switch box only contained connectors, switches, and a bunch of wire, so it was pretty simple. I seldom use voice modes, so didn't bother with switching microphones. I just connect them when needed. However, there are microphone switches available.
If you have to also share a computer connection, for rig control or digital modes, another switching arrangement can also be set up.