HFU HF Underground
Technical Topics => The RF Workbench => Topic started by: fpeconsultant on October 02, 2023, 2341 UTC
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Anyone have a fix for this?
While taking the antenna feed/lead off of a Wellbrook loop today I realized that the small center copper (?) wire at the center of the male bnc connector on the lead has broken off flush and is still “in” the center hole of the female bnc connector that protrudes from the base of a typical Wellbrook loop head.
Any body have any idea how I might get that small bit of wire out???
This could only happen to me.
Thx
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If you can grasp some of that wire, tweezers should do the trick. A small pin might work as well.
When you put it all back together make sure you leave a loop (no pun intended) in the feedline so that there is no strain on the connector.
This is what mine looks like.
(https://i.postimg.cc/ZqXqjPdS/P4026551.jpg)
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Thanks thanks I will give that a try!
And I had a loop for strain relief so I am not sure what happened!
Ok thanks again.
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No luck so far - anyone else have any suggestions?
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Any chance we can get a picture to see what is going on?
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Any chance we can get a picture to see what is going on?
Sure - can you PM me your email or tell me here how to upload a picture - it’s just the loop head of a Wellbrook and you can barely see that there is the center conductor of the old male BNC fitting broken off in the center - I only figured that out because I couldn’t get another male BNC to slip on and couldn’t see why but now I do. I can fit a needle into the hole in the center of a new female BNC but not the one sticking out of the loop head. Ugh.
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The easiest way I found to post an image on the HFU is to go to https:/postimages.org/ (http://https:/postimages.org/) and drag the picture into the browser window. It will then give you a bunch of links for the image. The first 2 work fine and I usually use the second link and also keep the "delete" link in a text file just in case I want to delete that image later.
Take that link and paste it in the HFU message. Highlight the entire link then click on the picture frame icon (insert image). That's it.
I have picked away at these before using a dentist's pick cleaning tool. It is nice and sharp and the hook fits nice in the BNC. That centre female part of the BNC which captures the pin is slit in 3 pieces so that it can expand when the centre pin is pushed in. Hopefully it has not gone in too far deep when you tried to put on the new BNC male.
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Ok. So do you have any ideas on an easy way to try to spread the 3 parts ever sooooooo slightly to allow the busted off piece of the center conductor from the male to perhaps wiggle loose? I guess just “pick” at it as you suggested.
You see, I graduated from the brawn over brains school of thought so I will admit I leaned on it pretty hard to try to get that new male connector to seat! I’ve had to do that with brand new connectors in the past so I thought “what can happen??”
Thanks for your help!
And thx for the help on how to post a pic
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This is where the dentist's pick would come into play. You could start from the back and try to pick your way forward. I don't think there is a need to spread the centre any further as it is already being spread by the pin. As soon as you can get a grip on the pin you should be able to work it forward.
These are the type of tools I am talking about:
https://www.amazon.ca/Needles-Scalers-Stainless-Examination-Tools/dp/B07YYFZDMC/ref=asc_df_B07YYFZDMC/?tag=googleshopc0c-20&linkCode=df0&hvadid=459661178801&hvpos=&hvnetw=g&hvrand=5236327076054691263&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1002634&hvtargid=pla-945491837438&psc=1 (https://www.amazon.ca/Needles-Scalers-Stainless-Examination-Tools/dp/B07YYFZDMC/ref=asc_df_B07YYFZDMC/?tag=googleshopc0c-20&linkCode=df0&hvadid=459661178801&hvpos=&hvnetw=g&hvrand=5236327076054691263&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=1002634&hvtargid=pla-945491837438&psc=1)
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How do I “start from the back”? I can only access the front (the side you see when looking at the loop head). Doi need to open up the loop head to get to the inside of it?
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Oh no, no disassembly. The interior of the amplifier is potted / sealed so you would not be able to get to the components. I would use the long and slightly bent pick tool and insert it between the centre captive pin and the inside wall of the barrel of the BNC connector where there is a slit in the centre captive pin then try to rest the pointy end of the tool on a portion of the broken pin and pull it forward / out. That broken centre pin will have a small edge / lip between the back where the wire used to be soldered or crimped and the actual pin itself.
I know, it's hard to explain / visualize.
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Understood
I’ll let you know how I make out.
Thanks again for all of your help.
FPE
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No problems. I'll try and take a picture to explain it better. As an alternative to a dentist tool you could roll your own by bending the tip of a needle at a 45 or 90 degree angle. Those types of needles that seamstresses use to tack the material together when they do the hemming.
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This is what mine looks like.
(https://i.postimg.cc/ZqXqjPdS/P4026551.jpg)
I think that from a mechanical strain standpoint, mounting the BNC connector there is suboptimal. If I was the designer, I would have put it on the bottom of the head unit so that the coax can just hang down. In any case, as a user, I would have used a right-angle BNC male-female on the connector to do more-or-less the same thing.
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The amplifier is actually a separate assembly bolted together onto the base. When you order the antenna, you would get the same loop but there were different amplifier options.
I concur, the use of a 90 degree right-angle BNC male connector on the coax is a wise choice. One can always add a 90 degree adapter and achieve the same results.