Balun One Nine: cutting R1

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rjzastaury
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Joined: Mon Jun 06, 2022 10:53 pm

Balun One Nine: cutting R1

Post by rjzastaury »

I'm finally getting around to building a SULA. I have my Balun One Nine in hand, but I'm not clear on what cutting the R1 jumper/resistor entails. Can someone please tell me how exactly to do it? Pardon my ignorance...

Thanks,
Ron
Egil - LA2PJ
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Joined: Thu Jun 09, 2022 11:07 am

Re: Balun One Nine: cutting R1

Post by Egil - LA2PJ »

It is done to obtain galvanic isolation between the antenna and radio.

See here: https://swling.com/blog/2019/10/the-noo ... lun-19-v2/


73's
Egil - LA2PJ
rjzastaury
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Joined: Mon Jun 06, 2022 10:53 pm

Re: Balun One Nine: cutting R1

Post by rjzastaury »

Thank you, Egil. I guess I should clarify my question: How do I physically cut the resistor? Score across it with a knife?
Egil - LA2PJ
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Joined: Thu Jun 09, 2022 11:07 am

Re: Balun One Nine: cutting R1

Post by Egil - LA2PJ »

Just scrape it off whith a knife... Carefully!

Good luck!


73's
Egil - LA2PJ
rjzastaury
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Re: Balun One Nine: cutting R1

Post by rjzastaury »

Thanks!
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Andrew (grayhat)
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Re: Balun One Nine: cutting R1

Post by Andrew (grayhat) »

rjzastaury wrote: Mon Sep 04, 2023 4:24 pm Thank you, Egil. I guess I should clarify my question: How do I physically cut the resistor? Score across it with a knife?
see here

Image

you just use a cutting blade to cut the circuit trace, then use a multimeter to check if the two sides are disconnected; to rejoin the connection, use a soldering iron and put a drop of tin to reconnect the sides
rjzastaury
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Re: Balun One Nine: cutting R1

Post by rjzastaury »

Thanks, Andrew!
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Andrew (grayhat)
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Re: Balun One Nine: cutting R1

Post by Andrew (grayhat) »

notice that the V1 has the central tap, while the V2 doesn't so with the V2 there's nothing to cut
rjzastaury
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Re: Balun One Nine: cutting R1

Post by rjzastaury »

It's the V2 that I have. How is it done for the V2?
rjzastaury
Posts: 9
Joined: Mon Jun 06, 2022 10:53 pm

Re: Balun One Nine: cutting R1

Post by rjzastaury »

Do I scrape it here?
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