hi, any idea on how to scratch build a WWII German Star Antenna from a wire or guitar string

Using 1mm styrene rods:

http://www.treefrogtreasures.com/forum/showthread.php?14145-German-Star-Antenna-help&p=200255#post200255

Or:
http://www.modellismochepassione.it/en/ab41-dettagliare-senza-fotoincisioni/ (halfway the page under caption "Little metal tubes, plastic rods & metal wires."):

I think the star is made from flat strips, so I'd opt for one of the etch sets myself as trying to solder six strips at the correct angles at the same time sounds a bit tricky to me if you want the result to look symmetrical. I did once spend a boring flight sketching up a jig to make them from scratch but making the jig would take as long as ordering and waiting for the etch to arrive by post.

Note that the arms are thicker towards the central join, so you might consider laminating strips of 5thou styrene to the etched star to depict that. Doyle's drawings in various Panzer Tracts books (some of which, such as the Panther ones include 1/10th scale plans) show the construction. There are also rivets holding the strips together.

Hi!

SchwarzA has it pretty right for a typical small sternantenna as seen on a panzer. Tubes (rods) inserted into sockets in a base mounted onto a stabsantenna (rod antenna) (or onto a wooden pole - in which case one needs also a base-load coil for the star, and an antenna-cable down to the base mount). VERY NICE, SA!

But more generally, the salient question may be... WHICH sternantenna do you wish to make? There were several versions - ranging from 4 horizontal + 1 vertical elements to the general 6-element models which we see depicted on many kits and in PE sets.

"Sternantenna" were almost always constructed of copper tube - flat strips like what "we" (post-war western militaries) have used on man-portable radio sets were a rare item for the Germans. So, while they look neat, the PE sets don't really get there for the real look.

SA element length ranged from about 0.6m up to ca 2.5m - radio cars with extended mast sternantenna often supported those very large stars - some being over 3.5m across! The elements were generally made of tubing between 8mm and 31mm in diameter - smaller units used thinner tubes. The elements fit into a central hub - depending on the type, that hub could be a aluminum casting into which element tubes were fit before the assembly was fit onto a tubular "stabsantenna" or vertical rod, a larger and more-complex unit where the element-mounts hinged to fold the entire star for storage, or even a leather cone into which were fitted the tube-element seats (the leather cone allowing the elements to be pulled together to fit the star into a case for storage). This latter design was used on small sternantenna with shorter elements, as were small cast bases into which one inserted elements. Fixed casting mounts and bases assembled from multiple pieces for hinged elements were generally the norm for larger units.

So... for us modelers working with the smaller units generally seen on "command tanks" and auklarungspanzer; use small styrene rod or skinny stretched sprue or skinny wire for the elements, like SA did. Consider what base type you want to put them into... For example, those Italeri Italian armoured-car kits should use the "leather cone" base in general (these mast-mounted stars - of the earliest design - folded and slipped into cloth cases for storage), while commanpanzer stars often used a small star casting with elements stuck into it at fixed angle and spacing. In general, the star was either flat (the ground-plane), or a cone array at about 45 degrees. The cone was actually fixed in its element-angle - unless one has the flexible leather base, where the cone could be more varied (elements not all exactly 45 degrees). Of course, even tubular elements could get bent and this is seen in pics.

Model the cast base with tubes around a putty or styrene core - SA has caught that look with larger base tubes (sockets) and skinnier rod elements. (But SA needs to bend his elements up to get the correct 45, IF he is seeking to depict that typical panzer-style star... there were also horizontal 6-stars, and horizontal stars with a center vertical element).

There are some pics available of museum and collection relics - and numerous WWII images of various types on tanks, etc.

Bob