[Lowfer] Vertical antenna - off topic

[Ed Phillips]

J. B. Weazle McCreath wrote:

>Hello Lowfers,
>
>This is an off topic question concerning vertical antennas
>that are insulated from ground.  If the bottom end of the
>antenna was connected to ground (earth) via the coil of
>a sensitive relay, would the buildup of charge due to a
>nearby T-storm be enough to trip the relay?
>
>73, J.B., VE3EAR - VE3WZL
>Solar and wind powered
>Lowfer " EAR"  188.830
>EN93dr
>  
>
     Probably won't work as the resistance of the relay will be low 
enough to "bleed off" the charge as fast as it accumulates.  A better 
way, as suggested by others, is to use a neon tube between the base and 
ground, perhaps shunted by a small capacitor like 0.1 ufd or so.  That 
would integrate the current and result in a brighter flash.  For 
unattended operation you could observe the pulse of current which would 
flow each time the bulb flashed and use that to trigger an alarm.  You 
could also use a cold-cathode thyratron like an 0A4G with the control 
circuit connected to the antenna and the relay in series with a power 
supply and the anode.

     As a point of reference I once observed sparking across a BNC 
connector connected to a two-meter ground plane antenna [braid of BNC 
was grounded to a water pipe] when a large black "thundercloud" was over 
a mile away so you should have plenty of "signal" to play with.

Ed