My antenna rebuild

[roadrage]

I am nearing the end of my rebuilding of the base antenna that I grabbed out of my stepfather's garbage pile. Aside from the SO239 connector, it was in good condition until he heaved it off the roof. It took me weeks to find out what kind of antenna it was. It turns out it is an Archer Crossbow .64 base antenna, that is supposed to be a knock off of the Penetrator 500.

I got all my ground radials straightened out, which was quite time consuming cause I wanted them about perfect. They were pretty bad. The outer piece of one radial needs replacing as it was broken in two. I built a matching coil similar to what is on a Sigma 5/8 wave base. I used a piece of Aluminum flat stock that is 1"X 1/4"X6'. I just have to figure out how I am stabilizing the radiating vertical and it's ready to go up.

 

[HomerBB]

Sounds like progress. If you can, pt up some photos. And keep us posted.

 

[roadrage]

I haven't worked all week as construction is slowing down. I had some time, today, to do some more work on my base antenna rebuild. I just need a 4' piece of 1/2 aluminum pipe to replace one of the outer ground radials that was damaged beyond repair, a 4 more bolts to get the last of it together, and then its ready for a test run. I put some pics up to show my progress, fabrication, and upgrades.

 

[HomerBB]

You've gotten quite a bit done on it.
You're not far from done, and it's looking great!

 

[Robb]

Using an antenna analyzer? Or a SWR meter to do the setup? Looks great so far; I have an old RS antenna that needs coil replacement too. Might do the same matching system you are doing instead of rebuilding a little crappy coil. Keep it up and let us see the final product! Will keep watching this thread.

 

[roadrage]

Using an antenna analyzer? Or a SWR meter to do the setup? Looks great so far; I have an old RS antenna that needs coil replacement too. Might do the same matching system you are doing instead of rebuilding a little crappy coil. Keep it up and let us see the final product! Will keep watching this thread.

I only wish I had an analyzer and knew how to use it. I would buy one if I could but I way over stretched my budget when I bought an amp, even though I saved for a couple months for it. The wife really doesn't want me spending any more money for a while. So an SWR meter will have to do. My only worry is the position of the matching coil. I don't know if it needs to be above the ground radials, below them, or stradle them. Maybe it won't matter. I put it below becuase I am taking a guess that it should attach to the radiator at its base, which happens to be below the ground radials. But I made it out of a 6" X 1" X 1/8" aluminum flat stock that I found at the hardware store. I'd love to take credit for the idea. I got the idea from a thread, I think, by Bootymonster.

The factory matching system on these RS antennas does seem pretty chinsy. I don't know what the power handling is, but I doubt it is very much. I don't plan on running any power on the base. Just a barefoot Madison I asked for Christmas from my mother and stepfather. That may change some day down the road so its good to be prepared with something that won't have a meltdown. I saw a link someone posted for a company that sells aluminum online for radio antennas. I need to get the 4th radial together with some 1/2" tube. It was pretty cheap too. It ws going to be about $5 for the piece I need. My only problem is finding it again has proved most difficult.

 

[roadrage]

You've gotten quite a bit done on it.
You're not far from done, and it's looking great!

Thanks. I hope it works well. The best part is that I got the antenna for free when I rescued it from the garbage pile at my stepfather's lodge. Too bad he threw if off the roof when he took it down. It would have probably have needed some help either way though. It hadnt been used since the early 80s. All the non conductive parts that hold the radiating element were in pretty rough shape, even before it took flight. When it is done I'll probably only have about $20 invested + time.

 

[HomerBB]

That will be a great price and an even better experience.
I don't know if having the matching ring below the radials will matter or not. I've only seen the ring above them before. If you find it a problem just move them above it. I would not straddle the radials with it though.

 

[roadrage]

That will be a great price and an even better experience.
I don't know if having the matching ring below the radials will matter or not. I've only seen the ring above them before. If you find it a problem just move them above it. I would not straddle the radials with it though.

I don't either, not that I have any experience in the matter. I just know that the factory matching coil, before I removed it, was below the radials and at the base of the vertical.

 

[roadrage]

I got my antenna out of the basement workshop and into the front yard. It is still missing one outer ground radial so I cut a piece of 1/2" copper pipe to substitute it until I buy an aluminum one. I put it all together. I wanted to do a test run with it. I used the handle of my hi-lift jack and pounded it into the ground for a mast. I took out the old Johnson Messenger to fire up the antenna out in the front yard. One the radio side the SWR meter read 1.3 on ch 1 and 40 and 1.1 on 19. I moved the meter to the antenna side and got it 1.1 on 1 and 40. I have to get my hands on a tripod for the roof and a 10
' mast. That should give me about 30' to the base of the antenna.

 

[The DB]

For you living in the "middle of nowhere" there is an awful lot near you, at least two other houses, and even a fire hydrant. Those don't exist in the middle of nowhere do they?


The DB

 

[roadrage]

For you living in the "middle of nowhere" there is an awful lot near you, at least two other houses, and even a fire hydrant. Those don't exist in the middle of nowhere do they?


The DB

My town is in the middle of nowhere. Pretty well smack dab in the center of Maine. If you drew a line straight north and another straight west, it is completely townless everywhere in between. Only logging roads and hunting camps. The nearest "city" with a mall is only 30,000 people and its 70 miles away. Even the nearest Walmart is about a half hour drive. I guess if I was truely in the middle of nowhere, I would have no need of a truck because there'd be no roads. I am right on the edge of nowhere instead of in the middle of it.

 

[HomerBB]

Looks like you are well on the way to a great antenna.
I replaced a broken tip on a Yagi element with a wooden dowel rod.
I wrapped the dowel in aluminum tape and it worked just fine. As far as that goes, I've made full sets of radials in that way.
Cheap, locally available even in the middle of nowhere, and effective.

 

[BOOTY MONSTER]

nice project and it tuned good for ya too . were you able to hear and make and contacts ? i like the maco type tuning loop better than the coil type , but they can flutter in strong winds . in your case a simple non-conductive stick of something stiff across the flat part of the mounting bracket and attached to the ring edges and the bracket will steady it if it's a issue . maybe marconi can model the difference between the coils location . but every 5/8 i can think of has the matching device above the ground elements .

 

[roadrage]

nice project and it tuned good for ya too . were you able to hear and make and contacts ? i like the maco type tuning loop better than the coil type , but they can flutter in strong winds . in your case a simple non-conductive stick of something stiff across the flat part of the mounting bracket and attached to the ring edges and the bracket will steady it if it's a issue . maybe marconi can model the difference between the coils location . but every 5/8 i can think of has the matching device above the ground elements .

My wife was out and about when I set the matching network. I called her on the phone and told her to turn on her radio. We conducted a radio check and she reported +20 on her meter (Galaxy 929 with a K30 antenna) but was only about 1.5 miles away. My house was between us and the antenna was 18" off the ground. My Johnson had all meter lights lit when receiving her. I need better coax before this antenna goes on the roof anyway.

All I have is a 15' string of RG58 purchased at the Napa auto parts in the next town. So strike one is that its RG58. Strike two is that it is cheap RG58. When the SWR meter was on the antenna side, it was way different than on the radio side. I imagine that maybe better coax will lessen the difference between???

I'll need about 50' - 60' when the antenna is in its permenent place (center of the roof and on a 15' pedistal).