I liked Mr. Fry's last comment. Technically speaking, Audioguy has the right idea and did a good job talking about it.
Over the years I have re-invented this antenna system while experimenting with it. The original design had no ground system: this was my idea. I am not writing to brag about it, but to explain in layman's terms why a whip antenna won't work with the sstran, unless you are willing to go thru MORE work than the antenna actually takes now to properly tune it.
The sstran antenna design works best when both the coil is tapped correctly and the antenna is the correct length to match the correct choice in position where the antenna input connects to the coil. I've never said this before but it would be very nice if somehow we were able to pinpoint the exact place on the coil and the exact length of the antenna needed for a specific frequency beforehand. Honestly I personally would never be able to do that, so I doubt anyone else could either.
The wire I use to wind the coil is coated and the taps I form are scraped of this coating.
IF you used wire that was bare (I'm thinking out loud here), you could tap any part of the coil instead of the 12 taps I provide, HOWEVER it seems as though you would be tapping for a very long time to get it right, provided you were using a 3meter antenna that you could not change. Basically that is how it is done with commercial AM towers. Instead we use an antenna that, like a trombone, slides up and down to 'help' you tune the antenna, so you are doing two things by choosing a tap close to where you need to tune, and then fine tuning by sliding the antenna up and down milimeters at a time until it resonates. For wx protection, the coating left on the coil is also painted with laquer, so it does require protection, and that is another good reason to provide particular taps.
Coax connected to the CB whip is not the proper wire to use, so you would have to rewire the whip. But even if you chose a good spot on your un-coated coil, you would probably need to cut the whip antenna to the right length. If you cut it improperly, then you would be buying a new whip. I'm probably oversimplifing here but I'm trying to make myself understood.
In regards to the antenna connector, I'm sure you could adapt the coaxial wire connector in a way that would plug into the sstran. But I've experimented not only with a whip CB antenna, but with other versions of the antenna design we use, and the CB whip is just not effective with the sstran, no matter how you slice it. The coax is simply the wrong vehicle for the signal anyway.
If you used a CB whip, you would cut off the connector and almost all the coax leaving the positive wire, connecting it to the top of the coil. The ground wire of the coax is not used, as the sstran antenna does not ground out in that way. The transmitter ground is connected to the antenna mast. If you look at the antenna plans on sstran.com, you will see that the antenna wire (white) is cut to only be as long as to reach the uppermost tap on the coil. The ground wire is cut to reach the top of the mast pipe. Keeping these wires as short as possible results in a better signal.
You will notice that in the sstran antenna instructions, there is no mention of a ground radial system: that one was my baby. My thinking was to design the antenna to be as close to a commercial broadcasting tower within the framework of the part 15 laws. I experimented with several lengths of radial and different types of wire for the ground system before I settled on the type I build right now.
Even a small radial system improves the signal of the antenna, however I found that 10 foot long radials work the best simply because it mirrors closely the length of the antenna. You will also notice that the notes regarding the antenna installation on the sstran website do specify placing the antenna way above the ground. Installing IN the ground was also "my baby", and because of my experimentation, that is what "I" recommend on board and to my customers. But the antenna was originally designed to be installed above ground, using a ground wire and lightning rod, as written in the sstran instructions.
Basically, when the subject of sstran transmitters and it's antenna system come up on this board, people write about what they have heard about it, some write about what they have read in the sstran instructions, and some write using theory, math, and FCC law, all of which are well and good. Often I read a combination of these things. And some write with the intentions of changing the design or in this case, using a CB antenna and telling why it will work. Also well and good and it would be much better if, after building and trying these designs, you report on how it works instead of saying it will work when you obviously didn't try it.
I'll be honest here; I tryed just about everything you can before I decided to build and sell this antenna. The antenna itself is not hard to build, nor is it costly, but the coil and ground system is cumbersome to build and is tricky, and in the past few years, probably in the interest of saving money and time, most of my customers order coils and ground systems only from me, and build the rest. That is fine and good with me.
To make it more efficient, I've changed small details of the antenna; I build it 1/4" 'thicker' to improve the bandwidth and sturdiness of it. In fact it could be thicker if I wanted it to be. But more importantly, the Installation and Proper Tuning of it means the difference between a mediocre signal/waste of time and money experience and a killer signal.
While I was experimenting with my first sstran and the original antenna design, I happened to live in a place that was in a river valley, surrounded by mountains, on land that was formerly a farm, but that was more rock and bedrock than anything else. One piece of this land was damp most of the year due to water run-off and ground water, and sat 200 feet behind my home, almost surrounded by trees and directly behind my home, a metal mobile home! To me, this was automatically a real-world AM installation. And, for sure, after having talked to about 160 of my customers over the past 7 years, not many lived in a similar place....so I lucked out. I want to add that the soil conductivity at my place in the Poconos in PA is pretty poor. However it is very near the same kind of place where the best commercial AM antennas in this country are located, in a valley (not on top of a mountain) on a wet plain or near water. I installed the antenna in the ground, and used a radial system to benefit from these conditions, and I should add that having the large metal building nearby also contributed to making the antenna somewhat directional, but that is not the point. I wanted to see how different enviornmental conditions affected the antenna. So I mounted it there, installed it on top of my metal house (which had a metal roof), and in another area of the property that was high and dry and void of surrounding trees. I tried it without a ground system, with and without lightning rods.......on and on and every conceivable way I physically could. The wet, low, on the ground location, 200 feet away from the metal building was the most effective installation in regards to strength of signal and quality of sound. I'm not saying that you have to have the same conditions that I had in order to achieve the very best signal, but that I was fortunate enough to have a wide variety of test sites on my property in order to properly test the antenna.
Also I measured with a meter the field strengths, and I can tell you that the audio wires had no signal, and the ground wire was so short, the meter needed to be on top of it to register signal, which it surely picked up from the antenna pipe proper.
I've posted all of this information before over the years but it looked like a good time to rehash my personal experiences with the antenna design. It is not meant to drum up sales for me but to help settle some differences of opinion on the design itself. If you experiment with the antenna and sstran tx yourself this information should give you a heads up and help save you from making costly errors in time and money, plus hopefully give you a good experirience no matter if you are just in it to experiment, learn or to put on the air a small AM radio station. It is far from plug and play like the Rangemaster is, and it was never meant to be a Rangemaster clone. In fact at first it was never meant to put out a better signal than a 'whole house' transmitter would, but with the addition of the antenna system and small changes to the transmitter itself, it can. This is just the best way to use the sstran to your best advantage.
I have enjoyed reading all the various comments on the board, especially the ones about the sstran. But as you can see I haven't posted in a long time because I got tired of the arguements, mostly about how I am wrong, and often nearly all the posts regarding the sstran are the same over the years. It still amazes me when I read posts that claim to be expert when the poster has never before experimented with a sstran! They are interesting, but misleading at best. So I've spent my time here reading and not responding, until now. There are always new readers and posters to the board so rehashing information for them is good as long as the information is accurate and easy to understand. Remember, typical part 15'ers benefit from experienced users' posts and legal information but few if any understand 'complicated' engineering/legal information.
This kind of information serves to confuse novices, and please take it from me: after OVER 160 customers, I get on average 7 emails from every customer/potential customer many of whom have read this board, although not completely. Maybe if they read every post ever written they MAY understand all aspects of part 15 broadcasting. That is a lot of emails to respond to!
The misinformation out there about the sstran and about part 15 in general is unreal. I try to keep it simple and unscary. And I don't recommend to my customers to read this board, simply because this is more of a network for experts and engineers than it is for the part 15 enthusiast.
I hope my post was helpful and not a waste of your time. But I'm really not interested in challenges to my post(s) simply because I have told of my experiences with the sstran system truthfully and in an easy-to-understand way. The system you use is entirely up to you.
Carl
