Topband: Fw: T vert feed

[Brian Mattson]

----- Original Message ----- 
From: "Brian Mattson" <k8bhz at hughes.net>
To: "Guy Olinger K2AV" <olinger at bellsouth.net>
Sent: Monday, January 30, 2012 9:22 PM
Subject: Re: Topband: T vert feed


> Let me see if I have this right. With an unfortunate length of coax (half 
> wave or multiple thereof), the house ground rod appears as a 1.7 ohm 
> impedance at the base of the antenna feed. Why not avoid the tuned coax 
> complication and put a ground rod right at the vertical feed point. With a 
> 1/4 wave vertical at 36 ohms and a 1.7 ohm ground rod, efficiency is 
> better than 95%! I'm impressed....and who said a ground rod isn't much 
> good for verticals? Just think, you can pull up all those radials & sell 
> them for scrap copper...
>
> Brian  K8BHZ
>
> ----- Original Message ----- 
> From: "Guy Olinger K2AV" <olinger at bellsouth.net>
> To: "Roy" <royanjoy at ncn.net>
> Cc: <topband at contesting.com>
> Sent: Monday, January 30, 2012 5:32 PM
> Subject: Re: Topband: T vert feed
>
>
>> Oh, yeah.  It will. If you are unlucky and it is presenting a current 
>> node
>> at the antenna connection. All the MORE likely if you have a really good
>> ground at the house entry point. Get used to it.  Each little wire 
>> running
>> off from the center is a **DRIVEN** element in the system, and if the 
>> coax
>> shield is not blocked, the coax shield is an element DRIVEN with power 
>> from
>> the base of the antenna.
>>
>> It can be that low, it's insulated, it has a very large surface, and
>> because there are miscellaneous distributed and specific terminations at
>> the other end, you CAN very definitely have current nodes if it's driven
>> with power at the antenna end.  That is where you can get VERY low
>> effective series resistances.  Maybe you particularly will, maybe you
>> won't, with your SPECIFIC piece of coax and routing, grounding, yada, 
>> yada.
>> But the warning of the 50/50 possibility has to remain.  I'm really quite
>> sure some of you out there ARE lucky in this very miscellaneous regard.
>> Carry on.  Enjoy life.  Kiss a pretty woman.  Work rare DX.  As for the
>> REST of you.....
>>
>> The trick is to remember that without a block you are driving that shield
>> with counterpoise power, the same as each one of the radials 
>> individually.
>>
>> 73, Guy.
>>
>> On Mon, Jan 30, 2012 at 1:53 PM, Roy <royanjoy at ncn.net> wrote:
>>
>>> This is the part I'm objecting to:
>>>
>>> "the coax will carry HALF
>>>  the counterpoise current and waste most of that power, besides being a
>>> link...(etc.)"
>>>
>>> No, no, nertz. Where did that notion originate?
>>>
>>> Roy   K6XK
>>>
>>>
>>>
>>> _______________________________________________
>>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>>
>> _______________________________________________
>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>