Topband: Receive ant - binocular cores

[tony.kaz at verizon.net]

Hi Tim,

I have used these BN-73-202 for quite a while. This is the only one that was in such small pieces.

N2TK, Tony

 

 

From: Tim Shoppa <tshoppa at gmail.com> 
Sent: Monday, October 5, 2020 8:42 AM
To: tony.kaz at verizon.net
Cc: topBand List <topband at contesting.com>
Subject: Re: Topband: Receive ant - binocular cores

 

Tony, I have abused BN-73-202 cores at the 100W level when I accidentally transmit into the receive antenna through the transformer. I have smoked the termination resistor but never damaged the transformer by transmitting into them.

 

I have used single BN-73-202 cores at the several watt level continuously, in step-up/step-down voltage inverter applications.

 

None of the above means that the core would survive a lightning strike.

 

The ferrite material is mechanically fragile. When (for example) PCB mounting in outdoor conditions you have to take into account the lead stress from temperature changes etc. I think the two-hole BN form is way more mechanically robust than the skinny rings but I have broken both kinds due to mounting them "too tightly down" to a PCB.

 

Tim N3QE

 

On Mon, Oct 5, 2020 at 7:19 AM tony.kaz--- via Topband <topband at contesting.com <mailto: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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