[Milsurplus] AN-104

[Marty Reynolds]

Jack u wrote:

> I was looking for another manual tonight
> and came across AF manual 52-19, "Antenna Systems"
>   |
>   |
> It goes on to
> say the radiation resistance is approximately 50 ohms
> so no matching section is necessary, and for a resonance
> at 128 mc, the antenna can be used from 100 to 156 mc.
>
> Now it would be interesting to know if this is a
> simplified description, or an accurate representation
> of the insides of the AN-104.
>
> Jack Antonio WA7DIA

Perhaps 100 & 156 are 2:1 swr points.  Maybe 70 ohms @ 156 & 30 @ 100.  Thats
center freq. +/- 20%

It's old wisdom that to broadband a dipole you increase element diameter.
So if AN104 some 6" around that sheathed wood core, you'd have an effective
L/D ratio of 10%  (L=19", D=1.9").  At 3.75 mhz that'd be about L=70' & D=
1.8" to give a 2:1 swr band from 3 to 4.2 mhz.

I wonder

Now isn't  the antenna is a streamline tear-drop  cross-section?   So
D=6" would deform to a 1.9" diameter circle

Many have seen station fotos where the wire dipole elements have spreaders
that form
an abstract cage.  Reason: broadbanding.  In fact I think there's such a
drawing in
an ARRL antenna book.

I don't have the math & hygeine to support such.  I'm clearly writing from
a corner marked "Empirical."

A ARC-5 VHF manual is here & will snoop

Tnx W7DIA