Topband: Receive ant - binocular cores

[Ken Boasi]

Hi Tony,

I also use the BN-73-202 cores for my Beverages and have also experienced the self-destructing core phenomenon. Not often, but I have occasionally opened up one of my Beverage boxes and found the two windings perfectly intact, hanging from the connectors, with the remains of the core broken into small pebbles, scattered around the box. 

I’ve never figured out what it was. The best guesses were from moisture that had somehow gotten into the boxes, which settled on (or in) the core, and went through enough freeze/melt cycles to cause the core to crack. 

There was no evidence of any lightning hits; no damage to my switching equipment, radios, coax, or other components in line with the antenna. 

I have never accidentally put power through the beverages, so it wasn’t that. I just figured I had done something wrong in the construction and this was the result. 

Interested to see some of the theories on this; I had always wondered what could cause this. I have only witnessed it maybe twice or three times in the last dozen years or so. 

73, Ken N2ZN 




> On Oct 5, 2020, at 7:19 AM, tony.kaz--- via Topband <topband at contesting.com> wrote:
> 
> I use BN-73-202 cores for my receive antennas - Pennants, BOGs.
> 
> Finally getting time to check out my receive antennas. One BOG was very low.
> The BOG transformer was broken. I mean it was totally destroyed. The largest
> piece was 1/8" long. The primary and secondary wires, #30 were intact and
> neither open or shorted. The wire looked pristine. Any ideas what could do
> that to a ferrite core? Any reason I should change anything other than just
> wire another transformer?
> 
> N2TK, Tony 
> 
> _________________
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