High quality relay box to interface between any radio providing a POSITIVE voltage (5-15 VDC) * and will key any amplifier***.
Many newer radios can only provide for a small amount of current on the external amplifier keying output.

*IMPORTANT: THIS VERSION ACTIVATES WITH A POSITIVE VOLTAGE APPLIED FROM YOUR RADIO TO THE "RADIO AMPLIFIER KEYING" JACK ON THIS INTERFACE.
You connect your station 13.8 vdc power supply to the power leads then you apply a positive voltage from 5-15 VDC to the "Radio Amplifier Keying" jack to activate the interface box which closes the internal relay to provide a closure of contacts to the "amplifier" output jack.
Radio amplifier keying jack (input from your radio switching circuit):
Center + 5-15 VDC from your radio to activate
Outside of jack is ground of your radio

Amplifier this will key *** The output of this interface is a closure of contacts 
We have many models that use the more conventional "ground to activate", see our other listings.

Again, this model requires a "positive" voltage 5-15 VDC applied to the input RCA jack to activate. 
Even if you order this because you did not read the ad and want to return it, IT IS NOT RETURNABLE!!

Our box will draw <5 MA from your radio and will key any amplifier. A very handy accessory. Get one BEFORE you damage your radios amplifier keying output!
RCA jacks in and out
Needs 9-15 VDC at only 40 ma! 
Relay rated up to 240 VAC at 5 AMPS!
Genuine relay used for switching (not an easy to damage solid state device)
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Need to key TWO amplifiers? See our eBay store listing for the RBI-2 TWO amplifier keying relay interface
Need to key MORE than two linears? Contact us for custom made amplifier ptt relay keying interfaces. (We just finished a SIX unit amp keying box, keyed from a single radio)

This is not one of those types that make you use a battery to power the unit! This high quality device is power by your station power supply or any filtered DC source from 9-15 VDC (only 70ma required)

When connecting your Radio and Amplifier, there may be switching voltage, polarity, and current incompatibility  that can cause damage to your radio or amplifier if connected without a switching interface between them. Even if your internal radio switching looks like it might be usable, it is wise to have an extra degree of isolation between your amplifier and radio with our relay buffer interface.

73, Dan W7RF ( Radiodan ) 

Ham Radio amplifier amateur amatuer radio amplifier relay buffer interface