Soldering questions

[Nathan]

I'm trying to build antenna's for some 900MHz wifi cards.

Because I'm on a tight budget, I'm building the antenna's myself.

-Nathan

Nathan,
I hope you are doing the appropriate research on biquad antenna dimensioning and scaling to 900 Mhz. The ARRL Antenna Handbook is available at most libraries and has some useful info on antenna design and math. As you have seen in the articles, the authors had some trouble soldering to the outside of the N connector. They thought is was lack of heat, but likely it was the metal used to plate the connector. If you were to use standard hardware to mount the connector to the ground plane, (keep the hardware short please) you could solder a wire directly to the ground plane. To do this, use a longer piece of wire, bend the end (about 1/4-3/8") at 90 degrees and solder to the ground plane. Once soldered trim to the correct length for to set the antenna above the ground plane. At 900 MHz, a helical antenna may be an easier choice to construct and terminate.

[karlcswanson]

Isn't Wifi 2.4/5 GHz? Are you making an antenna like this?
http://www.engadget.com/2005/11/15/h...-dish-antenna/

[DonRotolo]

Most of the previous advice is pretty good.

If I was to make that antenna, I'd first solder the double loop up with a small butane torch. Then use a soldering gun (the big ugly ones that should never go near a circuit board) to make the final connections to the connector.

Use 'helping hands' to hold stuff on place.

After assembly, use some silicone sealer to stabilize the joint mechanically.

The point about dimensional accuracy at 900 MHz is 3 times as important at 2.4 GHz; a fraction of a millimeter is important here. Unfortunately, you likely do not have the equipment to measure the results, so just be as careful to be as precise as you can.

By the way, if you want a directional WiFi antenna, I wrote an article on that, see ftp://ftp.tapr.org/psr/Autumn_85_2002.pdf on Page 8. Let me know if you ahve any questions on that.

Don

[Nathan]

Isn't Wifi 2.4/5 GHz? Are you making an antenna like this?
http://www.engadget.com/2005/11/15/h...-dish-antenna/

That's the kind of antenna I'm trying to build. I posted the link in my previous post but it got edited accidentally.

Thanks for the article Don! I'll make sure to read it. Any more advice would definitely be welcomed. I've been practicing on some spare wire I had laying around, I'll see if I can post a picture of on of them to make sure I'm doing it right.

Thanks,
Nathan