INCLUDES High quality buffered interface between IC-705 radio and our RBI-1A will key any amplifier*.
Many amplifiers have a voltage or current requirement too high for the delicate keying circuit inside the IC-705!
Get our cables and buffered interface BEFORE you damage your radio!

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 for keying the interface from your radio and output to your amplifier T/R relay control
Needs 9-15 VDC at only 40 ma, has 2.1 x 5.5 mm DC jack, universal plug and 5 feet of wire included, center positive
Relay rated up to 240 VAC at 5 AMPS! 
Genuine relay used for switching (not an easy to damage solid state device)
INCLUDES:
IC-705 keying cable, 3 feet long
RBI-1A buffered interface
PAX100 keying cable, 3 feet long
These are high quality, high copper braid RCA connector cables 
Hard to believe I need to state this but the COLOR of the RCA plugs is IRRELEVANT! 
WHATEVER color of RCA plug is not important! The cable with the 3.5mm plug goes into the ICOM IC-705 KEYING jack.
The cable with the white connector goes to the PAX100. 

How to test this setup:

Power the RBI-1A with your 12 vdc power supply, center of DC plug is POSITIVE.
Connect RCA plugs into RBI-1 (IC-705 cable goes to "From Radio amp keying", XPA cable RCA plugs into "To Amplifier relay control"), 
Short the TIP to it's shield of the plug that would go to the IC-705 and the RBI-1A will now provide a closure of contacts on the output jack of the RBI-1A which sends the XPA-125B into the transmit mode. 
Shorting (same as radio providing a ground on transmit) the input jack to the RBI-1A will activate the RBI-1A and cause the output jack of the RBI-1A to close contacts (thus completing the amplifier relay T/R circuit)
Use your DVM on the input to measure the current needed to key the RBI-1A, see that it is <5 ma. This PROVES that there is NO WAY this setup can damage your IC-705 (or any radio!). The RBI-1A is transistor BUFFERED and has a reverse EMF diode.
ICOM has had many reported problems with their amplifier keying transistor in the 705. They have sold thousands of 705 radios and you can read about this chronic problem in various forums.
Our RBI-1A has been protecting radios from keying transistor damage for over 10 years! 
In general, It appears that many problems arise from poor and closeby antennas causing RF to be picked up by cables entering and leaving a radio, aggravated by a non-robust amplifier keying transistor in the radio.
If you have any issues with your radio or amplifier, you can now see how there is no way the RBI-1A and cables could cause any damage. 
As of this writing, there are over 450 sold just from this listing alone and those buyers (as well as the thousands of other buyers of our interfaces) are enjoying their radio to amplifier operation.

We our eBay store listings for our complete line of Amplifier Relay Buffer Interfaces.

In other listings we have models with 2 radios and a bypass switch, 2 or more amplifiers or other device (like noise reduction unit keying, mute, etc)

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 )