Is it not possible to discuss this question by considering the design of two
UHF verticals mounted on a car?
The corollary of the original question would then suggest this is not possible,
since you do not have separate radial fields (since the car IS the radial
field).
But we do know it is possible, because we see examples of it at every hamfest,
every field day and many emcomm events.
I would suggest that it is never a bad thing to get as close as you can to the
theoretical "perfect" radial field (an infinite plane of copper). Even if that
means two antennas share the radial field.
But overlapping isn't necessary: where any wires meet, cut them and bond them
to each other.
Don't ask me for the math: K9YC I ain't!
73,
Kelly
Ve4xt
Sent from my iPhone
On May 23, 2011, at 7:46 PM, "pfizenmayer" <pfizenmayer2@q.com> wrote:
>
>
>
>> "terminated in a common bus". I take that to mean they are tied together
>> rather than overlap without touching?
>>
>> Ken
>>
>> On Mar 18, 2011, at 5:08 PM, pfizenmayer wrote:
>>
>>> Antenna Engineering Handbook by Jasik says -
>>>
>>> " Individual ground systems are required for each tower of a multielemnt
>>> array . If the individual systems would overlap , the adjoining systems
>>> are
>>> usually terminated in a common bus."
>>>
>>> Under fig 20-16 showing radial systems for a two element array - It goes
>>> on
>>> to state " The adjoining systems do not overlap but are terminated in a
>>> common bus."
>>>
>>> E.A. LaPort's Radio Antenna Engineering shows the exact same situation .
>>
> Yes - nothing overlaps without touching - visualize two radial fields
> lying so they overlap at about 1/4 of the diameter , then draw a straight
> line across where they overlap perpendcular to a line between the centers of
> each field , along that line all the radials are terminated and tied to a
> common bus.
>
> Sure wish we could attach a drawing -
>
> Hank K7HP
>
>
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