Building a RCA Bus to Allow Several Radios to Trigger an Amplifier

My friend George W9EVT has a fairly unique hamshack.

Most of the hundreds of radios are easily usable, but he keeps Eight radios on the ready.

There is Switch Gear from DX Engineering that is set up so W9EVT can switch between his main radios – currently a Hilberling PT-8000A, a Kenwood TS-990S, a Yaesu FTdx-5000 Classic, a Flex-6300, an Icom IC-7610, an Icom iC-7300, an Icom IC-7800 and a Ten-Tec Omni-VII.

The DX Engineering Antenna Switch selects the various mono band and multi band yagis, and other loop antennas.

The main Palstar HF-Auto Tuner allow switching to another antenna, which honestly I’ve forgotten.

W9EVT also bypasses the Antenna Switch by using the additional three outputs from his main Alpha-9500 amplifier.

To trigger the Alpha-9500 (and any other amp) W9EVT has a hodgepodge of RCA cables with Y-splitters and gender-changers running all over behind his radios. Mostly effective until its not, and always a mess.

Not able to find an off the shelf solution for an RCA bus that would take eight (or more) radio leads and redirect it to two (or more) amplifier leads I’ve order an Amazon product meant to switch AV Games cables (4 in 1 Out Switch). The units runs $12 including Prime delivery –

I will rewire to put all four outlets as 12 parallel RCA connections to each radio, and rewire the three outlets for the trip cable to the amps.

Uncertain until I get one open if the four push button switches will be useful or will be hot melt glued into an inoperative position or simply removed.

A bit of paint to cover the original markings and some label making to mark the new usage – and for much less cost of buying a small enclosure and 15 RCA jacks I should have a working bus for George W9EVT.

As usual I am building second units as a spare at the same time, as I’ve found Murphy’s Law applies less to the well prepared – especially when their radio station is out on an Island.

[EDITED 03 July – This type of bus provides NO protection between the radios and amps plugged into the device.  You cannot use this sort of a bus for AC (or other high voltage) circuits.  If you plug in several amps and leave the amps energized in their respective operating settings it will trigger all the amps.  There is NO logic in the device, just a nice way to make the connections.]



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