Antenna Matcher for 10-12 meters?

[Robb]

I'm using a single CB 1/2 wave bought at a garage sale of $15 (too bad I couldn't find an old Radio Shack 5/8 wave - that is my favorite antenna. Anybody have one for sale?). Took it apart and replaced all of the bolts, nuts, screws with stainless steel parts. Put it back together and hooked up a 35 ft piece of RG8/U Foam. Set it up to the wall of the HAM shack with 2-10' masts with a 4"x4" by 4 ft block underneath to support the base of the antenna with a 1 1/2" pipe cap drilled and bolted to the block. The mast is held to the side of the building by 4 - 1 1/4" pipe clamps that have been lag screws and flat washers into the flat side of a 2x4 walls stud.

OK - got that out of the way.
Now, what can I do to use this rig to run an export 10-12m radio and get a perfect match on this antenna? An antenna matcher - of course. But which one would be best, and what are the pitfalls - besides haveing to change setting when going from 10 meter to 11 meter to 12 meter?

I have been out of radio for over ten years, so I am not so hip to the newest gear available. Is there a reasonably priced 'auto-matcher' that doesn't cost 100's of bucks? One would think so; but I do not know. If no one has marketed such an item, I would be very surprised. I know that HAMS have them for their big boy 160-10meter setups; but is it overkill to get one of those units to make it work the way I want?

What are ALL the options available to me to make this work?
What would YOU do?

 

[hookedon6]

first of all... is the support mast grounded? if not , install a proper ground.

don't worry too much about "a perfect match" . can you adjust the length of the antenna? (make it about 10% shorter for 10 meters).

12 meters is a real small slice of bandwidth, i wouldn't worry about it.

 

[W5LZ]

One of the 'pitfalls' of tuners is that they are usually rated in 'Pep' power, not 'Rms' or average. So, getting one that will handle twice the power (plus a little bit more for 'over-head') is a very good idea. Most tuner's ratings are a bit 'optimistic', sort of, and making allowances for that is 'good'.
I can't speak for anyone else, but half the fun of it is twiddling them knobs! Don't misunderstand, I do have an automatic one built into a radio (very nice), but they typically won't handle an antenna that's really out in 'left field' very well. Once you find that 'sweet spot', mark it or write it down! After that, it's just a matter of tweaking it a bit when you move. Not really a 'biggy'.
As for being out of the hobby for a while, the problems are still about the same. There are just different 'routes' to 'curing' them. You still end up in the same place, just by a different approach. More comfortable with an 'old fashion' way of doing it? So what, do it. Wanna try something 'new'? Hey, nothing wrong with that either, knock yourself out!
- 'Doc

 

[Moleculo]

The cheapest auto tuner I've ever seen is from LDG - the Z100 which is $149. You might be able to find a used one for less. You can find little manual tuners for a lot less. Since you're only going to switch between three bands, you could quickly remember the settings, or just tape them to the tuner so you can quickly switch over.

Another CHEAP option is something like this: Paradynamics - PDC30 - Antenna Matcher - CB Radio Superstore WalcottCB.com

Just find the settings for each band and then mark it with a sharpie. I saw several of these at the flea market this month...I could have picked them up for cheap for you. For the price of a new one, you might as well just order it from walcott though .

 

[BOOTY MONSTER]

would this also work for what hes looking for if hes not running power ?
SWR and Power Meters

 

[Wire Weasel]

I think you would like one of the MFJ 949 series antenna tuners. Have the cross needle meter reading power and SWR simultaneously, 30 or 300 watt ranges, and like two antenna ports plus a bypass setting. Set your antenna up where you want it, probably on 11 meters, then the MFJ will have it working on 12 and 10M for you.

Loads of used ones available, check ebay. New one is around $150

 

[Moleculo]

would this also work for what hes looking for if hes not running power ?
SWR and Power Meters

Yeah, that would probably work, too.

 

[W5LZ]

Booty',
Would that tuner/meter work? Good question, and I have no good answer. I think I'd have to pass on it though, at that price. Sounds odd, but it's too cheap, one of those too good to be true thingys. I'd be happy to find out that I'm wrong about it, but I've got a feeling I'm not. Sorry 'bout that.
- 'Doc

 

[Robb]

The LDG Z100 looks like a sweet possibility; although one of those little cheap tune-it-yourself gizmos will probably do - because I do not plan to use power - and I am cheap.

More like 2W dead key and 'shweenging' to 25-30W; and SSB power shouldn't kill the little $17.95 tuner or exceed its design specs.

I have an 8 ft grounding rod w/clamp that I haven't put in yet. Don't have the grounding cable yet. Would it be a better idea to cut it in half and have two ground stakes? I was reading on some HAM site, that it is another means to spread the ground field along a greater surface. Anyone ever do it that way? In fact, they used four 4 ft pieces in the ground with the grounding wire between them buried 1 ft deep. Salt was added to the fill dirt and mixed - then watered - to increase the conduction of the ground circuit.

Thanks for all of the tips!

 

[949Jake]

Booty',
Would that tuner/meter work? Good question, and I have no good answer. I think I'd have to pass on it though, at that price. Sounds odd, but it's too cheap, one of those too good to be true thingys. I'd be happy to find out that I'm wrong about it, but I've got a feeling I'm not. Sorry 'bout that.
- 'Doc

I used one for about 8 months in my mobile until it quit working. It had a different name brand on it, but same exact design. I can't exactly remember why it quit working, but I wouldn't be surprised if it was due to simple misoperation.

 

[W5LZ]

Rob,
About that grounding/ground rod. Depth has little to do with a good electrical/RF ground. As long as it's deep enough to not cause probelms, trip over it, tie up a lawn mower, etc, it's deep enough. A simple, single 8 foot ground rod does as much 'grounding' if it's laid flat on the ground rather than being driven as deep as it'll go. A mile or two of wire buried deep enough so that you don't get it caught in the lawnmower will work just dandy! That 'mile or two' is an exaggeration, but this is another area where 'more is better' is really the truth. How 'good' a ground you have is entirely dependent on how conductive the dirt is. Some just ain't gonna be a very good ground no matter what you try. If there's green stuff growing in it, it's probably about average, sort of. That bit about sowing the ground with salt sounds like a good idea, but it isn't. That salt tends to kill things and it loves to 'eat' metal. It really doesn't last all that long anyway. Typically, insulated wire lasts longer than uninsulated wire/cables/rods/whatever. No, that insulation doesn't make all that much difference in what an RF ground system does. The absolute most best thing you could do is thickly copper plate your yard! There are problems associated with that so would you please furnish lots of pictures when you do it?? Tell the neighbors to just shut up. It'll eventually turn green and be prettier than their yard anyway. They're just jealous!
- 'Doc

 

[Robb]

My uncle was telling me today (a USN electrician/Ret) that #4 stranded or solid core copper wire will be sufficient for grounding this sytem. It is cheaper to do it that way - as opposed to using tinned cooper braid - which is really very $$$. And I am cheap; does this info work with your experiences as well? Thanks!

 

[W5LZ]

I'm sure #4 wire ought to be big enough for most anything you'll do with grounding. I happen to have had some yards of larger cable used to run a second battery in a vehicle left over so used that to get out of the house to the first ground stake (too short to be called a ground rod). From there it branched into several runs of #10 (I think) that ended up going for some distance away from the shack. I continued adding those 'runs' until I just got tired of the whole thing and quit. It did make a difference. Long story short, all that was because of an interference complaint, city court, then state court. Finally was dismissed because of lack of jurisdiction. I was certainly willing to go to federal court, which does have jusrisdiction but the 'complainer' wasn't (think he finally did some reading and found he was in the wrong). That type of grounding meets the NEC, by the way, and is really worth doing, legally as well as for practical reasons. Hope you never find out about either reason...
- 'Doc

 

[Robb]

Wow; it had to go that far. If they would have filed in the right court it would be different. Their mistake - your gain. Unless you wanted to confront the Fed's over RF.

HAM's will use expensive filters for their radios. But is it necessary for CB's to do the same? If one has a HAM license and operating on the CB, then they are bound to the rules to work with compliance and ensure that they run their station in accordance with sound operating practices and engineering. I'm not even aware if there are notch/low pass/high pass filters available for 11 meters - is there?

I guess having irate neighbors would necessitate finding out. So much RF/CB interference is created by harmonics of the antenna being transmitted thru resonant lengths of masting or an ungrounded antenna if I remember correctly. But so many people have cable TV these days that it isn't much of an issue. At least as far as I am aware of. But I have seen that grounding a base station antenna has done much to eliminate a great deal of RF interference. I've also seen it improve my SWR as well, so it's not all bad...

 

[Moleculo]

I wish I had the ability to do better station grounding outside also. The problem of course isn't inside the shack; it's outside. I used some wide copper sheet metal that I cut into about a 2" wide strip to get from the bench to the wall access. Since that stuff isn't flexible enough to get through the access panel, I had to use 1" ground strap from there, which is tied to ground rod just outside the wall. The problem is to install the ground rod, I first had to drill though about 6" or more of concrete. And I had to drill the hole wide enough so I didn't have to worry about it exploding if I got a lightning hit (coax is grounded there also). One ground rod isn't really that great, but there's concrete beside the house running the whole length, so it's difficult/impossible to run wire. I would have to drill a few more holes and drive more rods and tie them together to really do it right. Problem is how close together the rods would have to be, though. Oh well....