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Site for DIY 2.4Ghz impedance equipment help
Hi all,
I saw a site where a fellow designed a unit to measure impedance at 2.4 ghz, for use on wifi antennas. I don't recall if it was return loss or impedance. It gave detailed instructions on how to build and he also had ready built units for sale. I think it was a ham that designed the unit. I also think he was not in the states, possibly a P or PY call sign, but the memory is not good! Any help would be appreciated. Thanks, Mike |
Site for DIY 2.4Ghz impedance equipment help
In message , amdx
writes Hi all, I saw a site where a fellow designed a unit to measure impedance at 2.4 ghz, for use on wifi antennas. I don't recall if it was return loss or impedance. It gave detailed instructions on how to build and he also had ready built units for sale. I think it was a ham that designed the unit. I also think he was not in the states, possibly a P or PY call sign, but the memory is not good! Any help would be appreciated. Thanks, Mike This it ? http://www.frars.org.uk/cgi-bin/render.pl?pageid=1085 73 Brian GM4DIJ -- Brian Howie |
Site for DIY 2.4Ghz impedance equipment help
"Brian Howie" wrote in message ... In message , amdx writes Hi all, I saw a site where a fellow designed a unit to measure impedance at 2.4 ghz, for use on wifi antennas. I don't recall if it was return loss or impedance. It gave detailed instructions on how to build and he also had ready built units for sale. I think it was a ham that designed the unit. I also think he was not in the states, possibly a P or PY call sign, but the memory is not good! Any help would be appreciated. Thanks, Mike This it ? http://www.frars.org.uk/cgi-bin/render.pl?pageid=1085 73 Brian GM4DIJ -- Brian Howie A piece of Sage Wireline and a PCB to terminate it would be easier. Chris |
Site for DIY 2.4Ghz impedance equipment help
On Sun, 18 Oct 2009 13:41:23 -0500, "amdx" wrote:
Hi all, I saw a site where a fellow designed a unit to measure impedance at 2.4 ghz, for use on wifi antennas. I don't recall if it was return loss or impedance. It gave detailed instructions on how to build and he also had ready built units for sale. I think it was a ham that designed the unit. I also think he was not in the states, possibly a P or PY call sign, but the memory is not good! Any help would be appreciated. Thanks, Mike This is a copy of my reply to your duplicate posting to alt.internet.wireless. Please don't do that again: This one? http://pe2er.nl/wifiswr/index.htm or one of these: http://www.qsl.net/n9zia/wireless/appendixF.html What I do is use a return loss bridge as in: http://www.qsl.net/n9zia/wireless/pics/rtrn_loss_bridge.png I've built several out of chip resistors and junk parts. I have one that works well up to about 8GHz. Great for testing antennas. That's what's inside a Telonic Rho-tector (which can usually be found on eBay for cheap). A few models go up to 2.4Ghz. You'll also *might* need a microwave load or three. 50 ohms for a reference, but also some other known values for calibration. The problem is that you'll need an RF sweep generator to use this effectively. It's also not a VNA (vector network analyzer) so it won't tell you if any reactance is capacitive or inductive. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Site for DIY 2.4Ghz impedance equipment help
"Jeff Liebermann" wrote in message ... On Sun, 18 Oct 2009 13:41:23 -0500, "amdx" wrote: Hi all, I saw a site where a fellow designed a unit to measure impedance at 2.4 ghz, for use on wifi antennas. I don't recall if it was return loss or impedance. It gave detailed instructions on how to build and he also had ready built units for sale. I think it was a ham that designed the unit. I also think he was not in the states, possibly a P or PY call sign, but the memory is not good! Any help would be appreciated. Thanks, Mike This is a copy of my reply to your duplicate posting to alt.internet.wireless. Please don't do that again: Sorry, I thought about putting it on these other groups just as I hit send. This one? http://pe2er.nl/wifiswr/index.htm or one of these: http://www.qsl.net/n9zia/wireless/appendixF.html What I do is use a return loss bridge as in: http://www.qsl.net/n9zia/wireless/pics/rtrn_loss_bridge.png I've built several out of chip resistors and junk parts. I have one that works well up to about 8GHz. Great for testing antennas. That's what's inside a Telonic Rho-tector (which can usually be found on eBay for cheap). A few models go up to 2.4Ghz. You'll also *might* need a microwave load or three. 50 ohms for a reference, but also some other known values for calibration. The problem is that you'll need an RF sweep generator to use this effectively. It's also not a VNA (vector network analyzer) so it won't tell you if any reactance is capacitive or inductive. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Site for DIY 2.4Ghz impedance equipment help
"Brian Howie" wrote in message ... In message , amdx writes Hi all, I saw a site where a fellow designed a unit to measure impedance at 2.4 ghz, for use on wifi antennas. I don't recall if it was return loss or impedance. It gave detailed instructions on how to build and he also had ready built units for sale. I think it was a ham that designed the unit. I also think he was not in the states, possibly a P or PY call sign, but the memory is not good! Any help would be appreciated. Thanks, Mike This it ? http://www.frars.org.uk/cgi-bin/render.pl?pageid=1085 73 Brian GM4DIJ -- Brian Howie Thanks for the site Brian, that is not the one I was thinking though. Jeff found the one I wanted, http://pe2er.nl/wifiswr/index.htm Mike |
Site for DIY 2.4Ghz impedance equipment help
On Sun, 18 Oct 2009 13:41:23 -0500, "amdx" wrote:
Hi all, I saw a site where a fellow designed a unit to measure impedance at 2.4 ghz, for use on wifi antennas. I don't recall if it was return loss or impedance. It gave detailed instructions on how to build and he also had ready built units for sale. I think it was a ham that designed the unit. I also think he was not in the states, possibly a P or PY call sign, but the memory is not good! Any help would be appreciated. Thanks, Mike For the price of 1 tranceiver http://www.youtube.com/watch?v=N0w5U0Xj1MU w. |
Site for DIY 2.4Ghz impedance equipment help
On Mon, 19 Oct 2009 09:22:17 +0200, Helmut Wabnig hwabnig@ .- --- -.
dotat wrote: For the price of 1 tranceiver http://www.youtube.com/watch?v=N0w5U0Xj1MU Clever but I think the OP wanted test equipment, not tuning methods. Also, I noticed that the markers were set to 2400.500 and 2900.500MHz instead of US band limits of 2400.0 and 2483.5Mhz. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
Site for DIY 2.4Ghz impedance equipment help
"Jeff Liebermann" wrote in message ... On Mon, 19 Oct 2009 09:22:17 +0200, Helmut Wabnig hwabnig@ .- --- -. dotat wrote: For the price of 1 tranceiver http://www.youtube.com/watch?v=N0w5U0Xj1MU Clever but I think the OP wanted test equipment, not tuning methods. Also, I noticed that the markers were set to 2400.500 and 2900.500MHz instead of US band limits of 2400.0 and 2483.5Mhz. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 So did the (plexiglas?) change the velocity factor for tuning. Ya, I'll take his test equipment. Mike |
Site for DIY 2.4Ghz impedance equipment help
On Mon, 19 Oct 2009 06:34:06 -0500, "amdx" wrote:
For the price of 1 tranceiver http://www.youtube.com/watch?v=N0w5U0Xj1MU So did the (plexiglas?) change the velocity factor for tuning. The plastic raised the dielectric constant of the space between the patch and the ground plane. In effect, it increased the effective wavelength of the patch slightly, thus lowering its tuned frequency. You can (accidentally) get the same effect by tuning the antenna, and then placing it inside a PVC radome, which will also slower its tuning frequency. The author will probably find himself re-tuning the plastic piece after he's installed the patch antenna in an enclosure. Ya, I'll take his test equipment. Mike Build your own test equipment first. When that fails, mortgage the house, wife, kids, car, dog, cat, toys, etc and buy something better. However, beware of test equipment envy. Once you get on the test equipment upgrade path, nothing you own will be good enough, and there always will be something better. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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