Forum thread and RFB
I hope it's good day for all! All apologies for me being so naive in regards to Part15 transmitting. I am very grateful for this forums input, and you have been very informative RFB. I am aware of the greater distance AM will cover. My real concern is even with a proper coil based antenna, there will be an unknown in any environment we may go into. Events are for one night and move on in hopes of a re-book. Testing In the field at showtime, dusk, is not the time for a problem or multiple problems. Tuning the antenna, hum, sky noise are issues not for the novice I have learned.
What is the best solution for our situation. Ease of set up without worries that we can provide transmission service as contracted is most important. I have read where multiple FM transmitters is an option. I have seen some very reasonable prices on FM transmitters, China products mostly which is a concern. I am still doing research on antennas for the ATM3000, which is my issue at present. Perhaps the ATM5000 is an option, not sure as no reviews. Do I understand there is a coil on board for the ATM5000 and would this help? I thank you for your kind indulgence and tutelage.
Regards
Randy in Orlando
raecampus, you are asking for a solution that will work on show night without any rehearsals in advance. That is unrealistic.
You will only discover whether it will work by holding experimental tests at each site you intend using. Only then will you know what to expect.
Another factor not yet discussed is a question of how the presence of vehicles will re-shape the coverage pattern of your transmitter.
The AMT5000 does have a built in toroid loading coil, thus providing the freedom of not having to build a coil yourself.
In my setup I replaced an AMT3000 with an AMT5000 and the coverage range increased dramatically, even though I have a less than ideal antenna.
The advice on this website will always talk within the limits of the part 15 rules, and those rules are very stingy with little fussy bits.
For speed in setup and tear down the TH with or without the ATU for AM, or the CZH 05 for FM. Both do not require building from kit form and most likely will serve well for the purpose.
A little inside info on CZH's
These are very good units despite all the nay saying. There are some "clone" units out there that look exactly like the CZH units. AVOID THEM!!! Those are the ones that put out a junky signal and degrade in performance in a very short time.
The CZH 05 unit with its included whip will do the job and keep the signal within expected range and field strengths, not precisely but low enough that it will be apparent your not trying to throw too much power. They have an on-board 3 pole filter and can be powered from a 12VDC source, such as a car battery or small motorcycle battery if need be.
If you are into kit building, the EDM unit is a good choice also. Vastech also makes a pretty good little unit, except it has no enclosure so you would have to make an enclosure for it..preferably a metal enclosure.
It all would depend on how much time you want to spend on setup and tear down, or on the onset, building a kit and not running into any problems.
I am still not sure the ground rod method for AM is the way to go since your going to be going from one place to another, and having to deal with site owners, administrations etc, in getting permission to poke holes into their fields..especially a golf course. Even though a ground rod wont make a hole any larger than a "fat" pinky finger, by the time you do several shows, you may end up with a bunch of shallow holes that will no doubt affect the way a golf ball would roll over them...totally ruining someone's game for sure!
But hey if they allow it..go for it..that is if you want to spend the time slamming the ground rod in, connecting it all up and tuning up, then after the show yank that ground rod out of the dirt with a puller. Even a 4 foot long ground rod, you wont be able to yank that thing out of the dirt with your hands or pair of pliers!
A dent puller with a clamp on the end to clamp down on the ground rod and then yanking the counter weight to pull the ground rod out will work. Sure will get a lot of arm and back workout!
Anyway good luck with the venture! Let us know how it all goes!
RFB
Yes campus guy, best of luck with everything.
A dent puller with a clamp on the end to clamp down on the ground rod and then yanking the counter weight to pull the ground rod out will work.
Sounds like a plan. I've not much at pulling 4' ground rods back out with a pair of vice grips, but I've witnessed more than one being pulled out that way by big armed men.
I've never left a four foot rod behind, though most times for the temporary installs only drove them about 3 feet in. It really depends on the ground your driving into on how difficult it is to get back out.
There was one time I actually pulled an 8 foot rod out with a fence puller and a tree.
For awhile I had some junk part iron rod that came off a golf cart, it had a narrow kind of slit section in the center of the bar and used to be able to barely drive the rod through that into the ground, and the mushroomed top of the rod would stop it from slipping through.. It resulted in having hand grips for two people to pull it back out with; it usually worked.
Anyway, I've had my share of reusing ground rods!