Anyone build an 8-port coupler?

[KE0TBT]

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

 

[prcguy]

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

For receive only or transmit?

 

[KE0TBT]

For receive only or transmit?

Transmit

 

[prcguy]

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.

If your good with building stuff it would be easy to make an 8 port using a high quality ceramic wafer switch off eBay and an appropriate metal box with a bunch of chassis mount connectors.

 

[MUTNAV]

Are you planning on using all of the transmitters on the same frequency?

Thanks
Joel

 

[k6cpo]

A patch panel would be another alternative. You could build one with access to the eight radios and perhaps eight antennas (room for expansion.) This way, you could connect any radio to any antenna you might acquire in the future.

 

[majoco]

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...

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

 

[prcguy]

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...

​

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.

 

[tomhank]

You can design and build a custom antenna switch using coaxial relays. Coaxial relays are commonly used in antenna switches for ham radio applications. You would need eight coaxial relays, each with one input and one output, controlled by a control unit. The control unit can be a manual switch, a rotary switch, or an electronic control system.
Alternatively, if you find it challenging to build such a switch yourself, you might consider contacting amateur radio equipment manufacturers or specialty shops that may be able to provide or customize a solution for your specific needs. They may have experience with larger switch configurations and could offer guidance or a custom solution.

 

[K7MEM]

I'm wanting to connect up to eight ham radios to a single EFHW antenna. Has anyone built an 8-port switch or coupler?

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.

 

[KE0TBT]

Are you planning on using all of the transmitters on the same frequency?

Thanks
Joel

Each radio would be operated separately, one at a time, anywhere from 160-6 meters.

 

[KE0TBT]

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.

Do you have photo's of what you built?