The G5RV Jr is a half-sized G5RV antenna, theoretically covering 40m through 10m with the use of an antenna tuner.  I decided to give this a try as a portable multiband antenna as one major advantage over a 44 ft doublet is that the feedline (coax) can be routed along the ground which is convenient when you are camping etc. 

The antenna is 51 feet long. Mine is fed with 14 feet of 300 Ohm TV Twinlead followed by 41 feet of RG-6U. Approximately 16 feet of the RG-6U is coiled to form a choke just below where the twinlead connects to the coax .The choke is 10 turns of coax on a 6” diameter form (note that a large coffee can works well for winding the choke). The idea of using the choke balun is eliminate common-mode currents in the shield of the coax as this will mean the that the coax becomes a radiating part of the antenna and its positioning will impact the antenna impedance. We want to isolate the coax so that it can be routed along the ground without messing up the tuning.  

So far my practical experience with this antenna is limited to one outing where the antenna was deployed as an inverted vee using a 20 foot Shakespeare Wonderpole as a centre support.  The KXAT1 (internal tuner in the KX1) was able to achieve a 1.1:1 match on 40m, a 1.0 :1 match on 30m and a 2.2 :1 match on 20m.  I subsequently tried the Elecraft T1 tuner and was able to achieve a 1:1 match on 20m, as it has a much broader matching range than the KXAT1.

I worked WB2SPP in Tom’s River, NJ with a 589 report on 40m with about 3 watts out from the KX1.

I think it is a positive sign that the KXAT1 will match this antenna on the desired bands with its’ limited range as this implies that the SWR on the coax is probably not too bad, therefore, hopefully the resulting losses are minimal.