[Milsurplus] TCS Antenna Advice

[Rob Flory]

Hi,

.7A antenna current could be satisfactory.  The impedance of the antenna will determine how much current you can get.  I don't think you mentioned whether that was in AM or CW mode.

Short antennas, 1/8 wave and lower have lower resistive components of impedance and will show higher currents, but not necessarily work better. My 10' whip on my car loads on 3.8Mc with over 1.5A, but doesn't work that well(no surprise).  The TCS does want an antenna that shows capacitive reactance, ie shorter than a quarter wavelength, but you can trick it into loading into a longer antenna with external circuits.  

In addition to antenna current you need to pay attention to your maximum loaded plate current. When you get maximum antenna current, you should be close to the plate current marked on the meter.  If you are not able to load fully, you might need to change something with your antenna.  

Now, you are replicating a historical antenna, so you don't have as much flexibility as those of us who are just hamming.  One thing about whips on ships, is that they are great for communicating between ships sitting on salt water on surface wave.  That is all a TCS on an LCI was probably ever expected to do.  On a larger ship like the MASSACHUSETTS that was expected to be able to communicate over long distances they had 500-watt transmitters.

You will get much better results on CW as well.  I have worked stations out to 500 miles on 3.5Mc with the 10-foot whip from my car on CW.  On AM I think 7 miles is about as far as I have worked.

Long story short, if you are getting full plate current, adjust your expectations of what you will be able to do on the air.  How about a buddy "on the beach" with a TBX to talk your LCI in?  

Good luck,
Rob Flory