jason porter

DIY sharkfins (Ramsey LPY41)

45 posts in this topic

I finally finished my antennas, so far they work very well.  A huge improvement over whips in the bag.

I hit them with a coat of matte black spraypaint, so now they are 'stealth' :)

IMG_20150611_162421.jpg

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I think the antennas were about $30 each.

Plus additional hardware (female BNC, rg58 cable, etc) another $5-10.

The small L-brackets and nuts and bolts, another $5.

Stand adapters were about $20 each, I believe.

Paint-$7

 

 

 

 

 

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The fins themselves, did you make those? or purchase them and ad the coax etc?

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This is the post I have been waiting for! Sent from my iPhone using Tapatalk

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This is the post I have been waiting for! Sent from my iPhone using Tapatalk

Haha!

Well, if you have any questions...feel free to ask.

Jason

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Very impressed, nice work Jason! Hope to make my own one day.

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Got mine today! They are nice! I have a dew parts to get, but I'll put them together this week!

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Hey Jason,

The image of your finished antenna is no longer available. Could you post it again?

Thanks, Bob

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Thanks for asking Robert...thought it was me!  The fellow that builds the PC board antennas is a friend of mine.  Want him to see how his stuff gets used...and build a couple myself.....

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I'll see what I can do guys.  It may have to wait until I get back home this weekend ( to take a new photo)

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I finished mine this evening. I used RG174 to keep it light. I have Female BNC's on order so I'll change these SMA's out later.

I mounted them with an old mic clip, using the existing screw and 2 rubber washers to take up space and to hold them snugly into place. They seem to work pretty well so far. I put an HM on the other side of the house and it had nice signal...I chose that to test because it doesn't have an external antenna..But I also tested with my LT and it worked even better. 20150624_233958.thumb.jpg.b667c96d4847d020150624_233944.thumb.jpg.be7af17632c384

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How did you "plug into" the printed board? It looks to me like you just ran the cable along the side of the fin. Doesn't it need to electrically connect with the circuit board?

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It does indeed need to be connected to work! LOL The coax IS soldered to the PCB. The angle does not show the solder joint.

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Jason,

I think your post may have caused a small spike in sales over at Kent Electronics.

I just picked up two of the boards. Waiting for my connectors to come in!

 

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As promised...not the best pics, but I think they show the important details.

IMG_20150627_114531.jpg

IMG_20150627_114514.jpg

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My DIY sharkfins. Super easy to make (thanks Ken Wilkenson for the encouragement). 

I took some aesthetic license and went with PC board green, wood and brass. I used commercial conduit for the crossbar, but I didn't figure the paint would adhere to the galvanized surface too keenly. And it didn't. I'll switch it out for aluminum eventually. I also got SMA disconnects for the cabling. Been using them for a while now, and they work great.  

image.png

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Great work Rachel! I have my DIY shark fins (log periodic) antennas on my workbench now. I would suggest in time you add a right angle SMA connector at the wide end of the antenna so you can store the antennas (see photo #15 Matts). Let us know how they are working.

Mark

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Thanks Mark, for the suggestion. Currently, I'm working on a storage/quick deploy system for them. I've yet to figure out a way to hang the two splitters in a permanent, but out-of-the-way spot on the cart, too.

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Question for those that know more about this than I do - Could you put a connector at the larger end of the Antenna? Looks like the trace runs from one end to the other. Scrape away the Epoxy (or whatever it is) and solder to the other end?

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On 3/1/2017 at 10:15 AM, Rachel Cameron said:

Thanks Mark, for the suggestion. Currently, I'm working on a storage/quick deploy system for them. I've yet to figure out a way to hang the two splitters in a permanent, but out-of-the-way spot on the cart, too.

I mounted mine to a piece of aluminum bar stock by means of some hardware store L brackets, with the lower back corner of the circuit boards held in a sandwich of pieces of ABS plastic, bolted through.  (With a "baby" receiver bolted to the center of the bar.)  With the L brackets attached to the bar with a single bolt the antennas can pivot inward, so the thing folds flat--easier to transport--can even go in a case w/o being disassembled.   You can for sure think of a more elegant way to mount the fins, and I must say that they've held up really well over 15 yrs of use.  btw, what's inside the black fabric covering of an RF "Venue" antenna is basically the same "circuit board" type LPA.

I would not recommend trying to move the connector to the back--you might ruin the antenna by removing the connector from where they put it...

 

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