[Elecraft] Multiple sensors with P3 transmit monitor

[Alan Bloom]

On 07/25/2015 07:11 PM, Alan Bloom wrote:
> On 07/25/2015 01:01 PM, Dr. William J. Schmidt, II wrote:
>> I suppose the next thing we'll need is an outboard box to switch 3 P3TX
>> sensors automatically keyed off the ACC connector (amp off HF, amp on
>> HF, 2 meter).  Hmmmm. I wonder if anyone else has thought about this?
>
> You can buy manual RJ-45 switches on Amazon.  I just ordered one to try
> out.  10 bucks plus shipping:
>
> http://www.amazon.com/Network-Output-Manual-Sharing-Switch/dp/B00AUB3SSA/

This is a little box that has 4 pushbutton switches on the front that 
select one of four one RJ-45 connectors.  I received the unit a few days 
ago and finally got around to trying it.  It is quite small - about 4.7 
x 3.3 x 1.1 inches (11.9 x 8.4 x 2.8 cm).

I have it connected with short Ethernet LAN cables to three sensors: 
200W HF, 2000W HF and VHF.  The fourth position is "off".  It makes it 
quick and easy to select and de-select sensors for my testing.  The P3 
TX monitor automatically senses which type of sensor is connected and 
changes scale factors and calibration values as required.

I took it apart to examine the innards.  Each of the four pushbuttons is 
ganged to two 4PST switches, so all 8 lines of the RJ-45 connectors are 
switched.  It appears well-constructed with a good-quality PC board. 
The chassis is thin sheet metal, but perfectly adequate for the purpose. 
  One odd feature is that the pushbuttons are labeled D through A, left 
to right.  They did that so the connectors on the rear panel come out in 
the more-logical A-D order.

By the way, it should also work fine with a W2 if you want to be able to 
use more than two sensors.

Alan N1AL