Mixing to mono before sending on the cable is a very good idea, and reduces the exposure of the audio lines to unwanted influences.
What I mean is, if you put stereo on the cable, it would double the risk of the audio lines picking up interference. Mono cuts that risk in half.
I have to say; of all the stuff I have had (Gittings, Procaster, Hamilton) - this is the absolute best transmitter I have ever put on the air.
This time, without an engineer to help me, it took help from Phil (Awesome support!), and you guys here - but it is up, and holy crow does it put out!
Very pleased by your report, mir, on your approval of the AMT5000 as an outstanding transmitter.
Mine continues to resound everyday with my radio programming, and I keep it tuned in everywhere in the house and outdoors.
The special outdoor antenna I am building this summer will put the AMT5000 to the ultimate test. It is already tremendously effective with an inefficient antenna, I think opening it up all the way with the right antenna will be astounding!
Gives us more reports.
No - I am not hoping to gain psychic ability; I want to add a transmitter to a second location.
Other than getting the programming to the transmitter (which I have covered); is there anything I need to look out for?
The idea is to overlap where the signal is faint. so we will fade out, then back in as you drive.
The programming may be off by a bit; nothing I can (read: willing) to do to fix that...
Ideas? Caveats? "Don't be stupid, you can't do that" 's ?
Two problems that I know of, although I haven't done it myself...
First, the two transmitters will not be in syncronization because they are each generating separate and independent carriers, and they will NOT be identical, which will cause a warble in the overlap region. There are two suggestions for this: 1) use separate side-by-side frquencies so the mobile listener will need to switch to the stronger channel; 2) go BEYOND the overlap area and place a dead-zone between the two transmitters so they cannot interfere with each other.
But even if you could get the carriers synched, I think it would be a monster of a problem to get the audio on both stations perfectly at the same instant without an echo as one audio was ahead of the other.
Has anyone on this board done this?
First, the two transmitters will not be in syncronization because they are each generating separate and independent carriers, and they will NOT be identical, which will cause a warble in the overlap region. ... I think it would be a monster of a problem to get the audio on both stations perfectly at the same instant without an echo <snip>
Just to note that two, nearby "Part 15" MW AM transmitters even using the exact same, synchronous, carrier frequency can produce severe changes in the net r-f fields produced by that system around their joint coverage area, even with no program modulation (see link below).
Reception problems related to the inaccurate synchronization of the program audio used to amplitude-modulate those separate transmitters is another issue, still.
So it sounds like what I want to do is keep a dead zone between the transmitters.
OR; is there a way to sync them? I had seen GPS mentioned; I can get GPS modules really cheap.. ($6.50 without the antenna)
So it sounds like what I want to do is keep a dead zone between the transmitters.
True. But the dead-zone distance needed between those two systems for them to be essentially independent of each other as far as their joint coverage area probably is a lot greater than anticipated (maybe 5+ km).
If those two systems operated on carrier frequencies separated by 10 kHz or more, then the physical spacing needed between them would be reduced, and no synchronization would be needed between them (either for r-f or a-f).
OR; is there a way to sync them?
As shown in the link I posted earlier in this thread -- even when the r-f carriers of such nearby systems are exactly synchronized, their radiated fields combine in ways that produce severe variations in signal strength compared to that of either station, alone.
Probably best not to pursue this even in the ideal case, as the outcome is not likely to produce the desired result.
"Probably best not to pursue this even in the ideal case, as the outcome is not likely to produce the desired result."
NOTE: I realize that I am taking this out of the context it was presented in, so anyone reading this should clearly understand that this was not a shot at Rich. It was the statement taken by itself.
Which means I have to make it work now. That statement is exactly why Part15.us was started, why ekkoBSD was created, and why we (part 15'ers) build our stations.. 🙂
I am going to attempt the zero-beat method and see where this takes me...
The intellectual puzzle of solving some way of managing multiple AM transmitters on the same frequency might be comparable to a proposed FM technolgy named "Zone Casting."
Read about it here:
http://www.diymedia.net/archive/0413.htm#040413
Ok - not really.. but I did buy 50 feet of chicken wire.
I'll be putting that down in the morning.. when its cooler - and putting in my ground rod.. which is a blast... wish i could just wack it in the ground with a sledge hammer.. be a lot faster...
moving the 5' ratshack antenna mast to the ground.. got my hole dug, and a bag of quickcrete ready to be dumped in...
Progress!
Ground rod in the ground, just dug a little resevior and did the butter churn routine till it was all the way in there.
Ground plane is on the ground - 2 4'x50' rolls of chicken wire laid out, twity tied together.
Got some heavy ground wire that i wrapped around the rod and then to the chicken wire - stupid brazing torch wont stay lit though 🙁
Taking a break to shower and run the fam over to BK for the 50 cent softserv - woot!
Family can be pests sometimes when it comes to important Part 15 business.
The cone was a treat, I'm sure..
I still remember when I laid out my ground area and got things set up. I couldn't wait until I started tweekin' my SStran..
At first, I had it mounted to a leg of a wood swing with a counterpoise wire ran below across the yard, a 10' section of mast pipe, a coil below it with multiple taps. It worked but after I placed it over the chicken fencing with the antenna built from the instructions on the SStran site, it came alive!
Good luck and never forget the thrill!
I ran 3 rows of chicken wire; I now have about a 10'x20' strip of chick wire.
1) Do I need to have the tx and antenna directly over the center of the chicken wire? If not, and can get about another 10' giving me 20x20
2) When I tried to heat the wire with a brazing torch, the torch kep going out. Any tricks to getting the chicken wire soldered together? Tilting the torch seems to be a bad thing - all these years, and i never had reason to tilt a torch like that... just a plain old propane brazing torch.