RE: LF: EA5DOM <crazy> vertical

[VIGILANT Luis Fernández <luis@vigilant.es>]

Hi MF

 

I'm back again with is topic

 

While making some calculations for the <crazy> vertical I recalled Stefan's comment

"If C is 55 pF and your losses are 50 Ohm and the power is 50 W, you will have 6 kV on the antenna"

 

I'm using a Ultrabeam V6-40 vertical antenna. My idea is to use it just connecting the inner pin of the PL

to the loading coil, once removed the actual counterpoise wires for HF bands. The inner pin of the PL connects

with the copper-berilium tape which forms the vertical element of the antenna. It is rated at 3500W on HF

but I'm afraid that it doesn't mean 6KV of RF, but much less voltage on much more antenna current

 

My fear is not for the contact system between copper-berilium tape roll and the PL but for the stepping motor

which moves the tape. Even disconnecting the wires to motor controller, would it get induced currents

in the motor coils and get them QRT ??  

 

I wouldn't like to test it ..... the hard way :-(

 

There is not much information at manufacturer web site

http://www.ultrabeam.it/site/index.php?option=com_content&view=article&id=4&Itemid=27&lang=en

 

Probably the safer way would be to retract the original element completely and use just the fiberglass pole

to support a dedicated wire. But would be nice to keep using the retracting system as original and make

it easy to retract it all in case of storms

 

Any <crazy> ideas wellcome ;-)

 

73 de Luis

EA5DOM