Topband: [TowerTalk] radial lengths ...

[Herbert Schoenbohm]

One nice trick I have used in the past to locate buried radials and 
check them for continuity is to walk around the radial field with a good 
professional FSM (field strength meter) tuned to station's transmitted 
signal (at reduced key down power preferably to protect the transmitter) 
and with the loop close to the ground. Every time you walk across a 
buried radial you will see a slight blip or peak in the signal strength 
reading.   This may sound weird but it works. Broken radials may also 
show a blip but not as pronounced as a good radial.


Herb Schoenbohm, KV4FZ



On 12/1/2016 7:35 AM, Rob Atkinson wrote:
> You don't put down a lot of radials only for more return current; you
> put down a lot also because over time you'll probably lose some of
> them to damage or decreased conductivity or some form of disturbance.
> If your radial field is uncontrolled, and you can't watch it
> constantly, you may wind up with a doggie digging up and chewing on
> one, or who knows what else.   The assumption is that you want to do
> this once and have a ground system that will last for decades.  You
> also put down a lot of radials so that the return current on each one
> is less.  When you have enough, you will no longer need to fool around
> with "ununs" and other ferrite contrivances because 98% of the RF will
> be on the radials instead of your feedline exterior.
>
> If you have an inverted L that's the classic vertical length, around
> 60 feet high and 60 or more feet horizontal, (you can put bends in the
> horizontal part provided they are over 90 degrees) your feedpoint
> impedance should be low--10 to 20 ohms.  If it is higher than that,
> you need more radials.
>
> Are there out buildings in your ground system or on its periphery?  If
> they have metal--aluminum siding and/or a steel roof, you should strap
> them into your ground system using brass clamps and copper strap below
> grade back to your radial junction.
>
> What if such a structure is RF transparent but smack inside where you
> want radials to go?    You need to put copper strap along the
> foundation all the way around the structure and bond the interrupted
> radials to the strap, continuing in lines out the other side.
>
> 73
>
> Rob
> K5UJ
> _________________
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