Topband: RIG PROTECTION FROM BEVERAGES

[Eddy Swynar]

On 2013-01-15, at 4:25 PM, Wayne Willenberg wrote:

> I have my 2 reversible Beverages (designed by Tom, W8JI and sold by DX
> Engineering) installed and am thrilled with their performance!  Now I can
> listen in 4 directions, one at a time of course, with greatly reduced
> noise.  Stations I could never work suddenly pop out of the noise when I
> switch to the Beverage.
> 
> I did so much research on the construction and installation of the
> Beverages, I feel really stupid because I didn't think of one possibly
> critical aspect (nor did I see it discussed).  I have the 75 Ohm coax from
> the Beverages connected directly to the receive antenna input on my
> FT-5000.  If high voltage should get induced by lightning, isn't it going
> to fry at least the front end of my receiver?
> 
> How you you provided for this possibility?



Hi Wayne,

Obviously you do not employ any sort of an "isolation" (matching) transformer between your Beverages & rig...?

I wonder what harm (or good...?!) installing a 2.5 mh. RF choke might do for you, placed right at your rig & connecting the centre conductor of your coax feeder to ground...?

Remember the 2.5 mh. choke that's installed right at the antenna output of your linear amplifier...? Your amplifier doesn't even know it's there, until such time as the output coupling capacitor in the lead to your pi tank might short-out, whereupon the RF-blocking capabilities of that choke would be exposed to DC, and in so doing serve as a direct short of your B+ voltage to ground, blowing your fuse...

In theory, I s'pose, a lightning strike---a surge in DC voltage in your Beverage feeder---would act in the same manner, passing that DC surge directly to ground, as well...

OK all you gurus, experts, Poindexters, weisenheimers, & brainiacs out there reading this---LET THE FLAMING BEGIN...!   :o)

~73~ de Eddy VE3CUI - VE3XZ