Bias-T guide and diagrams

Various solutions for connecting Bias-T and LNA are listed here.

If you don't have a sequencer, there is an option where you use the radio's built-in RX/TX delay, which can often be set in the menu.

The files can be downloaded for free!

File overview:

YU1CF diagram

for use if you have a sequencer already.

The remaining diagrams are if you want to use your radio as a sequencer.

Diagram of LNA – IC-9700 w/Bias-T down by the radio or in the mast

IC-9700 delivers max 150-200mA, so to drive a high power LNA in the mast, an auxiliary relay connected to a power supply 12-14V 1A minimum is used. (Remember fuse)

This diagram is made for a dual band antenna with 1 feed point where a dixplexer is used to split the coax to the two antenna sockets on the radio.

In principle, it gives the same result, because a 12-14v control cable must be run up from the power supply, regardless of whether you put the Bias-T down by the radio or in the mast.

Diagram of LNA – IC-9700 w/ Bias-T in the mast and 2 feeding points w/ ant.

If you don't have a dedicated sequencer, you can use your IC-9700(/910H).

IC-9700 delivers max 150-200mA, so to drive a high power LNA in the mast, an auxiliary relay connected to a power supply 12-14V 1A minimum is used. (Remember fuse)

This diagram is made for a dual band antenna with 2 feed points where a coax cable is used from each antenna socket on the IC-9700 to each Bias-T and further up to the two EME2 and from there on to each feed point on the antenna.

Diagram of LNA – IC-9700 w/Bias-T down by radio / ant with 2 feed points + mast coax relay (1 coax down to radio)

If you don't have a dedicated sequencer, you can use your IC-9700 to control the LNA (PA).

IC-9700 delivers max 150-200mA, so to drive a high power LNA in the mast, an auxiliary relay connected to a power supply 12-14V 1A minimum is used. (Remember fuse)

This diagram is made for a dual band antenna with 2 feed points where an EME2 LNA is used for each band 144/432.

The antenna can be changed via a master relay which can be controlled manually via a switch or web relay below the radio or you can control the relay with CI-V from the radio,

so it automatically switches the antenna to the band you are using.

ATTENTION! You cannot listen to both bands at the same time (using both VFOs) unless you e.g. switches a dualband GP on the master relay bypassing the LNA as an option. It's either or.

I use the same solution in my home QTH with an SSB mast relay and a manual switch box down by the radio.

I have connected a Diamond X-50 dial band GP and a 5elm 2m yagi vertically to relay ports 3 and 4.

In remote QTH, I have used a CI-V relay control for HF/50/70MHz, so that I cannot choose the wrong antenna for the selected band on the radio.

The mast relay constantly follows my VFO and changes relay port when changing bands. I only have 1 feed cable up to 30/20/17/15/12/10/4/6m via the mast relay distributed to two antennas, a 50/70MHz dual band with two feed points and a 4 band HF beam with two feed points.

So 4 relay ports total are needed from your coax relay.