In early December 2022, I installed this inverted V doublet.  The location of the centre-fed radiator is highlighted in yellow, and the balanced transmission line ('feeder') is emphasised in white.

The doublet has a top of 2 x 23 m. The centre feed point is supported at 11 m above ground by a copper beech tree. 

The antenna radiator is made of PVC insulated multi-strand tinned copper wire (19 strands of 0.4 mm diameter) and was originally fed with 30 m of 300 ohm twin 'ribbon' feeder.   In April 2024, I replaced the ribbon feeder with home made open wire feeder to improve the stability of the match when it rained. 

Ribbon feeder suffers from a change in velocity factor when it gets wet, altering its electrical length and therefore requiring adjustment of the antenna matching unit to restore the SWR.  Open wire is much more stable when it rains.  No re-tuning of the antenna matching unit is required when it rains.

Normally, an MFJ-974HB balanced matching unit is used to do the transform to unbalanced 50 ohms.   But good results have also been obtained when using a home made switched balun in conjunction with a regular unbalanced antenna matching unit.  Having a balun that is switchable between 1:1 and 4:1 impedance transformation ratios can help to provide a better match with antenna matching units that have trouble matching a very high, or a very low antenna impedance.