chris_bollard Posted February 20, 2009 Report Share Posted February 20, 2009 Hi All Wanting to find out if anyone has had a try at making their own UHF helical antennas. Thanks Quote Link to comment Share on other sites More sharing options...
studiomprd Posted February 21, 2009 Report Share Posted February 21, 2009 Lots of Amateur (HAM) radio folks ---where do you think this stuff comes from?? try the ARRL antenna book! www.arrl.org Quote Link to comment Share on other sites More sharing options...
ve7kjr Posted February 23, 2009 Report Share Posted February 23, 2009 Hi Chris, I helped a friend build one years ago.I have the mechanical / electrical drawings with the equations,I hope you are really good at math ! I would have to scan the book and email it to you if you are still interested. VE7KJR (Phil) Quote Link to comment Share on other sites More sharing options...
mikewest Posted February 28, 2009 Report Share Posted February 28, 2009 Hi Phil, I'd be interested. You can contact me via my website Cheers mike www.mikewestgatesound.co.nz Quote Link to comment Share on other sites More sharing options...
Michael P Clark Posted March 1, 2009 Report Share Posted March 1, 2009 Phil, I'd be interested also. Quote Link to comment Share on other sites More sharing options...
ve7kjr Posted March 1, 2009 Report Share Posted March 1, 2009 I will set up the scanner tomorrow and see how well it will work, haven't used it in some time. I will email the files to both of you. VE7KJR (PHIL) Quote Link to comment Share on other sites More sharing options...
mikewest Posted March 1, 2009 Report Share Posted March 1, 2009 Cheers Phil I will report back Mike Quote Link to comment Share on other sites More sharing options...
soundtrane Posted March 1, 2009 Report Share Posted March 1, 2009 me too! -vin Quote Link to comment Share on other sites More sharing options...
ve7kjr Posted March 1, 2009 Report Share Posted March 1, 2009 To Michael Clark / MikeWest / Vin The scanner worked fine so I emailed the files 'Helical Antenna Design of to you today, let me know if you got them. And on a side note since Vin will be reading this, Congratulations on your sound design award! VE7KJR (PHIL) Quote Link to comment Share on other sites More sharing options...
Michael P Clark Posted March 2, 2009 Report Share Posted March 2, 2009 Phil, I did get the files, thanks. My reply to your email was kicked back to me. You're not kidding on the math side of things. And a tough build also. Almost worth the $400 to buy one. BTW, have you ever attempted this build? Quote Link to comment Share on other sites More sharing options...
ve7kjr Posted March 2, 2009 Report Share Posted March 2, 2009 Phil, I did get the files, thanks. My reply to your email was kicked back to me. You're not kidding on the math side of things. And a tough build also. Almost worth the $400 to buy one. BTW, have you ever attempted this build? Hi Michael, If you consider how much time you would have to put into the project,figuring out the math / getting the materials needed/ and then assembly, I would say several days at least. On the plus side, there is a great deal of satisfaction from building ones own projects and they work. I have not built one myself yet, however I did help a friend build one about 10 years ago for the microwave band (gigahertz) and it worked very well. When I have some more time, I will build one, do the field tests, post the results here with pictures ETC. Don't know why your email got bounced back,I just checked mine and return address works fine. VE7KJR (Phil) Quote Link to comment Share on other sites More sharing options...
mikewest Posted March 2, 2009 Report Share Posted March 2, 2009 Many thanks Phil. I think the build is not too difficult and with the NZ $ at 50cents to the US $ a PW antenna is $1000.00 of my money. To all interested have a look at this: http://www.rac.ca/tca/2006-01%20Helix%20Design%20Calculator.html Have found some interesting stuff on the web on helicals. Construction techniques and materials and stripline design. Will be having a go next week. Cheers mike www.mikewestgatesound.co.nz Quote Link to comment Share on other sites More sharing options...
soundtrane Posted March 2, 2009 Report Share Posted March 2, 2009 Phil, thank you, and yes, I got the files. Very interesting... Quote Link to comment Share on other sites More sharing options...
Adam D Posted March 2, 2009 Report Share Posted March 2, 2009 Hi Can you send me a copy to. Adam Quote Link to comment Share on other sites More sharing options...
ve7kjr Posted March 2, 2009 Report Share Posted March 2, 2009 Many thanks Phil. I think the build is not too difficult and with the NZ $ at 50cents to the US $ a PW antenna is $1000.00 of my money. To all interested have a look at this: http://www.rac.ca/tca/2006-01%20Helix%20Design%20Calculator.html Have found some interesting stuff on the web on helicals. Construction techniques and materials and stripline design. Will be having a go next week. Cheers mike Hi Mike, There is a lot of information out there for sure but just like everything else on the net you have to weed out the crap, the files I sent were from the ARRL (American Radio Relay League) Antenna Book which is a reference book and very well respected around the world.Although most of the information is related to amateur radio antennas, there is no reason that information would not work or be helpfull to us who use VHF/UHF transmitters/ recievers every day at work.The same principles apply,therefore it is a matter of doing the math to make the dimensions/spacings work within the frequencies of your radios.The impedance of that design is between 110to180 ohms and will need to be matched to 50 ohms. There are several matching systems designs none of which I have given much though to yet,that will come later. VE7KJR (PHIL) Quote Link to comment Share on other sites More sharing options...
ve7kjr Posted March 2, 2009 Report Share Posted March 2, 2009 Hi Can you send me a copy to. Adam You should add your email address in your profile in order for me to send a copy. VE7KJR (PHIL) Quote Link to comment Share on other sites More sharing options...
Michael P Clark Posted March 2, 2009 Report Share Posted March 2, 2009 Thanks for that link Mike. That sure does take a lot of the math out of the equation. Quote Link to comment Share on other sites More sharing options...
Adam D Posted March 2, 2009 Report Share Posted March 2, 2009 Sorry Phil Its was hidden. There now. Adam Quote Link to comment Share on other sites More sharing options...
Adam D Posted March 2, 2009 Report Share Posted March 2, 2009 Heres another link. http://www.antenna-theory.com/antennas/travelling/helix.php Adam Quote Link to comment Share on other sites More sharing options...
ve7kjr Posted March 3, 2009 Report Share Posted March 3, 2009 Sorry Phil Its was hidden. There now. Adam HI Adam,I emailed the files to you. VE7KJR (PHIL) Quote Link to comment Share on other sites More sharing options...
mikewest Posted March 3, 2009 Report Share Posted March 3, 2009 Not only do I have all the info I need but I have a PW unit for evaluation. I'm surprised at its size but I guess the results are the real measure. Construction is simple. Impedance conversion 130 down to 50 is achieved by using a length of wider foil from the end of the spiral to the BNC connector. Can't wait to make a start next week Mike Quote Link to comment Share on other sites More sharing options...
ve7kjr Posted March 3, 2009 Report Share Posted March 3, 2009 Not only do I have all the info I need but I have a PW unit for evaluation. I'm surprised at its size but I guess the results are the real measure. Construction is simple. Impedance conversion 130 down to 50 is achieved by using a length of wider foil from the end of the spiral to the BNC connector. Can't wait to make a start next week Mike Looks like the RACE in on,, who will be the first out of the gate with a working helical, looks like mike is in the lead followed by ? I'm so excited for you interest in this project Mike, if you could take some hi res. pics of the PW unit for me that would be great,would like to see some close ups of the matching network. Email them direct if you could .A great bit of detail has to be thought out on the matching strip, size / shape / thickness / angle and distance from the ground plane. Do you have an operating impedance bridge to measure the impedance? VE7KJR (PHIL) Quote Link to comment Share on other sites More sharing options...
chris_bollard Posted March 3, 2009 Author Report Share Posted March 3, 2009 Just logged back on after a short holiday (you all must know what that is?) and great to see that there are others on the forum interested in making their own helical. I'm interested in getting the scanned info. Also in seeing who cracks the prototype first. Quote Link to comment Share on other sites More sharing options...
ve7kjr Posted March 3, 2009 Report Share Posted March 3, 2009 Just logged back on after a short holiday (you all must know what that is?) and great to see that there are others on the forum interested in making their own helical. I'm interested in getting the scanned info. Also in seeing who cracks the prototype first. Hi Chris, Well you started this thread and I guess I got the ball rolling. I will email you the files later on this afternoon as I am just on the way out the door. VE7KJR (PHIL) Quote Link to comment Share on other sites More sharing options...
mikewest Posted March 3, 2009 Report Share Posted March 3, 2009 Will do Phil, I will evaluate it's performance on Friday and take some pix. No I do not have an impedance bridge for those frequencies. Cheers Mike Quote Link to comment Share on other sites More sharing options...
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