This is a rough IBM hi-AScii drawing of the Neptune dual band antenna for those
without MS Excel, it is NOT to scale.

          - - - - - - -
         ş              ł                     1.25" Stainless
         ş              ł                  A   1.404m
         ş              ł                  B   0.483m
         ş              ł                  C   0.057m
         ş              A   2m 3/4 Wave    D   0.064m +/-
         ş              ł                  E   2.837m
         ş              ł                  F   1.460m
         ş   - - - - -  ł                  G   0.169m +/-
      şC ¶  ş     ł     ł                  H   0.139m
      ş  ş  ş     B     ł
      ş  ÇÄ ¶ D   ł     ł
   ČÍÍÎÍÍĽ - - - - - - - - - - - -
         ş                       ł
         ş                       ł           22mm Copper
         ş                       ł         A   1.424m
         ş                       ł         B   0.497m
         ş                       E         C   0.052m
         ş                       ł         D   0.057m +/-
         ş                       ł         E   2.862m
         ş                       ł         F   1.494m
         ş   - - - - - -         ł         G   0.169m +/-
     ş   ş   ş      ł            ł         H   0.139m
     şÄHÄş   ş      ł            ł
     ş   ş   ş      ł            ł
     ş   ş   ş      F            ł
     ş   ş   ş      ł            ł
     ş   ÇÄ  ş- - - ł            ł
     ş   ş   ş G    ł            ł
 ČÍÍÍÎÍÍÍĽ- - - - - - - - - - - -
         ş    Not critical, set as
         ş    required from mounting.
         ş    - - - - - - -

50 Ohm coaxial cable fed up the inside of the centre tube is joined on outer to
the centre tube and inner to the stub, at the points shown as "G" for 6m and
"D" for 2m.  Dimensions H & C are the centre to centre spacing between both
stubs and the centre pole.

Tapping points G & D should be adjusted for best standing wave on each band.
Although the original words do not specify the precise construction, I suspect
the stainless design is mitre cut and welded, the copper version being
constructed from 90degree Yorkshire fittings, in that case (easiest for the
garage constructor) you need to calculate the lengths to allow for the
"Yorkshire" I've never seen a cruciform Yorkshire coupling, so how you organise
the centre of the tridents I don't know, maybe a TEE coupling, and drill out
the bottom?

Dimensions E + A form a 3/4 wave on 6m, dimension A forms a 3/4 wave on 2m

Drawn, by G8AMG with reference to the Excel picture by G0WEH.

For furthur reference, see the bulletins from G0WEH of the GB3PC/PD repeater
group, or contact the SOLENT Repeater group. Do a DC test to make sure all 3
wired are not framing. Then do a Ohm test

I have no contact or any vested interest in the above group, I just decided
that this Ascii copy would help reduce the otherwise soaring profit of a
certain software company, whose boss is rich enough by far.

73 De John, G8MNY @ GB7CIP