Homemade quarter-wave ground plane base antenna

**Jay Mojave** · 11-01-2016, 09:00 AM

Hello All: Yes these 1/2 wavelength dipole antennas work very well, better than the non ground plane fiber glass antennas from my experience. The only thing is that they require to be hung up from a tree or what even to be vertical as all the rest of the CB world. Or can used horizontal say for skip and such.

The home made dipole antenna can be made real cheap with two lengths of 103 inch wires and a 1 to 1 Current Balun, that is shown all over the net. Basically two wires wrapped around a Toroid Core type transformer, 8 to 10 turns, coax connected to the two input wires, the two 103 inch wires connected to the two output wires. These type antennas can take a couple of KW with no problem. I know guys who have these type of antennas strung up going different directions and polarities for switching them around to the strongest signal for distance DX stations.

The toroid core I use is a Amidon FT240-K toroid core at about 19 dollars each. See:

http://www.amidoncorp.com/ft-240-k/

I will use two of these cores epoxied together for the lower ham bands for a 1 to 1 current Balun.

Jay in the Great Mojave Desert

**mattsowders1989** · 11-01-2016, 09:09 AM

I've got a Hy Gain Super Penetrator 500 coming in the mail tomorrow. It's a vertical 5/8 wavelength antenna

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**222DBFL** · 11-01-2016, 06:15 PM

Yep Jay, I've found the dipoles to be a great antenna for DX'ing myself. And for SWL as well as for use on other bands with a tuner. They are cheap to make and do work well even when placed not real high off the ground. 18ft and you can do wonders. At 35ft which mine were last up at, man they worked great when the DX was rolling to keep up with guys. I too would switch between my 2 dipoles and my vertical and was able to switch polarity to horizontal when the vertical was in/out and vise versa. Helped to make many contacts for next to nothing cost wise compared to other antennas.
Matt, you just take your time putting up that spt500 and tune it correctly and it will work well for you. There are a couple of good mods that can be performed to the antenna as well that help. Do a search for mods for that antenna and you'll see what I am speaking of. And be safe placing it up. Try to get as many people to help you as possible to avoid bending the antenna or possibly hurting yourself trying to get it up in the air. JMHO's. Have fun with it and again, be safe!!

**Jay Mojave** · 11-02-2016, 07:54 AM

Hello M1989: Good deal on the Penetrator 500 hope it all works out for you. Hy-Gain rated this antenna at 1500 watts due to the CLR Antennas that they made before, were being burned up, a small matching coil in the base insulator made on a circuit board. The Penetrator 500 was a big upgrade.

Be advised I hear reports that the new SPF 500 antenna is shorter and guys are having problems getting them on the CB Band. Here is the assembly instructions for the new SPT-500

http://www.hy-gain.com/support.php?productid=SPT-500

The older Penetrator 500 assembly instructions are at:

http://www.cbtricks.com/ant_manuals/...rator_1975.pdf

And a few of the later versions of the Penetrator 500 are at:

http://www.cbtricks.com/ant_manuals/..._500/index.htm

Using a Antenna Analyzer will allow you to sweep the frequencies seeing were the antenna is working at or better said having the lowest VSWR. The Antenna can be adjusted for were you want it to work. There is a excellent article on this in this section of the Forum, called "Hy-Gain SPT 500 Super Penetrator"

Good luck, please let us know how you made out there...

Jay in the great Mojave Desert

**mattsowders1989** · 11-04-2016, 09:00 PM

Well I got the SPT-500 up and running. I took my time tuning it. SWR is flat for the most part. Past Ch 30, it hits a 1.1:1 witch I'm happy with. It was a bitch to get up but with a little help from the old man, I got it up and going. I will post pictures tomorrow with the daylight. It's hearing and talking far though!!

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**mattsowders1989** · 11-08-2016, 10:54 AM

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**mattsowders1989** · 11-08-2016, 10:55 AM

I hit skip this weekend barefoot on 4 watts. It was only one small contact but it happened. Everyone says I am getting out there strong and loud

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**222DBFL** · 11-09-2016, 06:15 AM

Good job. With the way conditions are that isn't bad at all. If the band is quiet and you get a good signal coming in just goes to show you don't need a lot of power to get back to them!! Now it might've been different if there were a bunch of people on the band or frequency you were on. If that is the case. Which I think it may have been. Right place and right time!! Job well done. Enjoy and keep at it.
If you haven't already done so, now would be a good time to make yourself a log book and start logging all your contacts. Get all the info you can. Date, time, signal report, numbers, name, frequency or channel, and so forth. It makes it easier when you again speak with someone you think you have spoken with in the past. Just some food for thought. Again, have fun and enjoy that new antenna setup. Looks good man!!

**Jay Mojave** · 11-09-2016, 10:42 AM

YO M1989: Can you tell us what lengths the antenna was assembled at, would help others out.

Jay in the Mojave

**mattsowders1989** · 11-09-2016, 10:46 AM

Total vertical length is at 26' 6.2"
That's from the bottom of the coax connector to the top of the screw for the hat. The radials are 104" each. Flat SWR until Ch 30. After ch 30, SWR is 1.1:1

Great performance.

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