The username "simonjersey" suggests to me that the member's name is Simon, and he lives in Jersey, a small autonimous island nation off the coast of France, in the English Channel, that is ruled by England, and in which the language is English. If so, it is no wonder that Simon seemed a little annoyed at being told here that he has only "limited" abiliry in his native language
Simon,
As for your proposed use of a random length of wire with your AMT-3000, longer than the US limit of 10 feet, you should get excellent results using long wire. The transmitter output stage tuning network is a capacitive input "L" network with a loading coil in series with the inductor of said "L" network. The collector load resistance of the output transistor is somewhere between 600 and 1000 ohms, and the "L" network transforms its output resistance to the correct collector load resistance. The loading coil resonates with the capacitance of the antenna, but since you are using a longer wire than is allowed in the US, you can use a smaller loading coil, and perhaps none at all, depending on how much of your wire you can stretch out. You'll have to fiddle around with tuning coils and collector capacitance to get your wire to resonate at the operating frequency.
The newer AMT-5000, also mentioned in this thread, has a tuning network surprisingly similar to the one used in the AMT-3000, even though the operating principles of the two transmitters are quite different. Particularly, there is a big drain-to-ground capacitor, C 8, that is not unlike the big collector capacitor used in the AMT-3000. The large inductance of the AMT-5000 tuning and loading coil prevents its use with a long wire. Anyone interested in doing that would have to bypass the tuning and loading toroid and replace it with a smaller inductor.
It may be that the Restricted Service License, available in the UK, is also issued in Jersey. This allows the use of 1 W on AM. This is a whole lot better than Part 15 AM in the US, and you should look into it, if you had not already.
It should be obvious that Mr. simonjersey's language ability was posed only as a possible reason why, after so many attempts from members to gather information and give advice resulted in being asked the same starting question as if we hadn't said anything. I was trying to find a way in so we could be of genuine help.
Carl: Most of us know you as perhaps the most active member of this forum; I'm certain you meant no disrespect ... My advice ... don't spend another second fretting or excusing yourself.
Simon: The members don't yet know you or your circumstances. The only information we actually have so far is that you have a SSTRAN AMT3000 and you're on the second floor of some building somewhere in Europe. The rest is all conjecture, so all we can really do is based on guesswork. IOW it may work for you, or perhaps not, in varying degrees. I estimate there is plenty of information to get you started ... now it's up to you to enjoy the fun of experimenting, which is what a great deal of unlicensed radio is about.
It's a learning process for all of us, tho' we're all at widely different stages in that process
For what its worth,
unlicensed broadcasting in England is illegal on any band. They have no "part 15".
Italy on the other hand, doesn't care.
That being said,
Just because you make the antenna longer, does not necessarily mean you'll get more useful range out of it.
I've found adding antenna length doesn't do much on the stock AMT3000. In fact, adding more grounds helped the most.
"I've found adding antenna length doesn't do much on the stock AMT3000. In fact, adding more grounds helped the most."
This is the case with any MW or LW setup. The ground system, or counterpoise, is very important. Being limited by an upstairs 2nd floor location presents a problem of it's own, but not make the job impossible to attach to a decent Earth ground through a cold water pipe or attaching to the Earth ground at the breaker box.
Long wire or short doesnt matter. The RF path must have somewhere to return to the transmitter to complete the circuit. No ground..no circuit path.
I should also point out something I have noticed here a lot with new members asking questions. Most responses seem to reflect that the poster lives in the US and immediately everyone breaks out the rule book and thumps it like preaching to a congregation. Might want to ASK first before making assumptions and causing the poster to react like this one did to the responses given. True the initial post lacked crucial information, but did anyone ASK the person where they were located? Only one and it was just assumed going by other information provided through an ebay link to the UK ebay servers. That alone does not prove anything as anyone anywhere can purchase anything from ebay no matter what country that particular ebay is originating from.
Moral to the story...ask before assuming.
RFB
There isn't much to choose from. The AC neutral is one possibility. kc8gpd reports using the ground connection for his TV cable.
I've tried to tune up a transmitter using an indoor monopole and the AC neutral. The apparent ground impedance was so high that it prevented proper tuning of the transmitter.
The best results I've obtained indoors is while testing a top-loading coil wound on a large polyethylene bucket. I placed the coil on top of a woooden step ladder in my living room. Even though the step ladder was less than 10 feet high, I got about 600 feet of range. Enough of the signal got out of my house, which is built from conrete blocks, to get this range. For this test, I covered a large part of my floor with several sheets of aluminum foil as a ground plane. Needless to say, this was a only a temporary installation.
It occurs to me that the story of Jersey during WWII has not been fully told in books and movies. They were under German occupation from the fall of France in mid-1940 until soon after the formal German surrender in May, 1945. I wonder how the island's civilian population and the German garrison were supplied after France was liberated in 1944. By U-boat? I don't know. To be sure, those had to be a hungry 10 months or so on Jersey.
I'm sure that Simon's elders had harrowing tales to tell.
I do hope that Simon chimes in again here to let us know how he is doing.
Thank you for the responses.
I agree that I wasn't as clear as I could've been but I'm very new to this. I am indeed in Jersey in the Channel Islands and I'm impressed by some of the knowledge you have on the place. It is a tad annoying to presume because I'm in Europe my English isn't so good. I'm English and we invented the language (and alllllllll of its oddities!... haha)
I wasn't born here though but I'm aware of the occupation. The island isn't controlled by the UK at all really and rules about broadcasting aren't clear at all. I'm not looking to cover a wide area, at the moment I'm struggling in the flat I'm in to hear it clearly around the house despite tuning it perfectly.
The sound quality is excellent for AM though, so impressed!
I'll take your points on board and will try increasing the ground and buy some longer wire!
Simon
Hi Simon,
Yep, I did a little historical reading about Jersey. Very interesting, not a British possession but rather a Protectorate. The island is actually a wee bit smaller than the one I live on!! Yet it has 'states', which as I understand it are actually parishes. I assume these are similar to the clusters of housing areas amidst agricultural areas ... we call those 'hamlets'. San Juan Island is in San Juan County, an archipelago of 172 islands (more or less according to tides ;)), North Puget Sound area of Washington State. Jersey could well be like a sister island to us.
I'd measure out exactly 3 meters (118") of #18 wire attached to the antenna side, and a very short ground lead to some sort of ground in the house ... but the audio input and power supply may be all you need, depending on how your house wiring is grounded.
You need to decide how to mount your antenna wire. You could set it near the floor and run it up a wall with the excess going horizontal or along a drape fixture ... in the middle of the house for in-house listening.
I ran the 'came with' wire for a Talking House AM real estate transmitter stuffed up in the crack on one side and over an arched top of an arch window on a second floor room, set the frequency (this unit will self-tune with a unique patented motorized ferrite loop system) and the darned thing got out a good 600' -700' or maybe even more, during late afternoon last winter. Nothing attached to ground ... the Power Supply was missing, so I got a two-wire one, and the audio came from a battery-powered netbook.
Also, I don't see anywhere in the discussion which unit you have (did I miss it?) ... i.e., there is one for US and Canada which will tune 530 kHz - 1700 kHz in 10 kHz steps, and there is also one for outside the US (and Canada) which will tune 522 kHz - 1710 kHz in 9 kHz steps. Of course, you have to set the DIP switches correctly for the frequency you want to broadcast on, so they'll be significantly different for the two models. The pi-netwrk should automatically take care of that part of the tuning process
Do you have a Digital Volt Meter to plug in the probes to measure max DC volts? After you set the DIP switches for the frequency, you need to adjust the trimmer capacitor using the DVM. That basically concludes the tuning process ... however, it may also need to be re-tuned if you move the antenna wire.
All that stuff affects range. You need to get it to peak resonance if you can, but it shouldn't be too difficult. When you hit it, you'll know ... it'll go from a few feet to a few hundred feet.
With the freedom to use a long length antenna I wonder how it could be done for the best result.
One limitation is being indoors, where the ceilings are possibly no more than 8-feet high, so only a limited vertical antenna would fit.
Another limitation is being indoors, with walls that will interfere with the signal in several ways.
A third limitation might be the transmitter itself, which is intentionally designed to be used with a short antenna. It is unknown if it will work well with a long antenna.
One thing I did once, outdoors right near a window, was raise a 6-meter antenna to see how it compared to the usual 3-meter antenna, and I was surprised that it was not any better at all, it was the same coverage.
If you have metal window frames you can try a method that works very well for me, connect an antenna wire to the lower part of the window frame by drilling a hole and using a self-tapping screw. I have two setups using window frames and they both cover the entire indoors and very well outdoors.
Definitely a ground wire from the transmitter clamped to a cold water pipe might help a lot to send the signal way out to the distance.
Another trick, used by amateur radio operators living in apartments is to run a long wire neatly along the baseboards of the whole house (or a large portion of it) and using this as a ground wire, with a short vertical wire for the antenna up to the ceiling.
It would be great if you will write back someday to report total success from the advice you found here.
Tie a sinker to the end of the antenna wire and flush it down the toilet. Pay out the line as it falls 3 or 4 floors through the drain pipe.
You may experience some impedance/SWR changes depending upon what your neighbors are putting down the pipe.
Yes, tougne in cheek but we found a contractor used the sewer lines to run some CATV down the road.
"Yes, tougne in cheek but we found a contractor used the sewer lines to run some CATV down the road."
Yeah, well, ummm, I heard the program content was nuthin' but crap (Sorry, just couldn't resist ;))