Great info for somebody like me who is just
figuring all of this out now.
Thanks for everything PhilB. Especially the 3000
and 5000.
Bruce
The AMT5000 kit does not include a separate "studio interface" box. Such a box is not really necessary for an outdoor installation. Such a separate box would increase the kit cost and assembly complexity significantly.
As Carl said, the AMT5000 accepts balanced pro audio twisted pair input as well as unbalanced consumer audio inputs. You can run two (left, right) unbalanced audio cables or one mono balanced cable. Its just a matter of where you connect the cables. No switching is required.
You can drive the cables with any consumer audio or pro audio source without a "studio interface". If your audio source is consumer audio and you want the pro audio feed, you can use an inexpensive active converter such as the MCM Custom Audio Line Level Converter, model 555-8485.
Concerning the built-in audio processing in the AMT5000, you only need to do a one-time setting of the MODULATION control to 100% modulation. This control actually sets the limiting level. Think of it this way: MODULATION control = limiting control. This setting will not change, so it is easy to set and forget. The limiting responds to the true RMS audio level and does not use distortion-causing hard level clipping. No distortion is introduced when you exceed the limiting level. Instead, the maximum audio level is held constant above limiting with no distortion.
The other control is the COMPRESSION control. It sets the compression ratio in the range of 1:1 to 5:1. Compression is equivalent to AVC or AGC (automatic volume control or automatic gain control). It just "rides the gain" automatically for you. It's pretty much accepted that you should use a compression ratio of about 2:1 maximum. That's about the 9 o'clock setting on the COMPRESSION control.
So, once set, the processing controls will not need to be constantly changed or tweaked. The only thing you need to be concerned about is that the level of your audio source is set high enough to guarantee the level at the transmitter is up to or above the limiting level setting. Once properly set, that won't change over time. Regardless, you can always adjust it by adjusting your audio source output level.
OK, so you insist on using an external audio processor. You can do that by setting the AMT5000 MODULATION (limiting) control to maximum to disable limiting and set the COMPRESSION control to minimum (1:1 compression) and use your own compression/limiting processor.
Those criticizing the AMT5000 for what it doesn't have, such as that studio interface, or its documentation, etc. are really missing the point.
You can choose to pay $700 to $1000 to get the niceties and a plug and play device. Or you can spend an awful lot less to get a box which has the potential to blow them all away performance-wise - with some extra work attached to it. Including potentially doing some research into how to tune it (over and above the provided documentation).
It's up to you. If you don't want the latter, then don't buy it. But it doesn't diminish the effectiveness of the product, or its potential.
I also think there appears to be a built-in set of assumptions in the criticism. The point is always made that individuals new to the hobby wouldn't want to go through the work necessary to get the AMT5000 up and running (including going beyond the documentation, if necessary).
In a word - balderdash (I'd use something stronger if I could). That's ego and an associated god-like complex from people that want to believe that they kinow everything, and that puts them on a pedestal. From what I've seen, most newbies are willing to do whatever is necessary to get the most out of their stations. And if they feel uncomfortable on the technical side, then they likely wouldn't purchase a kit in the first place.
If you don't like the AMT5000, then fine. But don't slag it because of that personal bias. And don't make assumptions about what other people will want (or not want) to do.
Oh that's right, I'd forgotten that the Rangemaster has the option of an out-board "Audio Interface" for an additional batch of $$$.
But, as has been reported above, an audio interface is simple balanced-to-unbalanced connection and level matching which, to even the beginning kit builder, is a handful of inexpensive parts to "do-it-yourself."
But more to the point, with the AMT5000 such an outboard audio interface would be redundant (meaning you don't need it), because the audio and power is able to interface ONBOARD the transmitter, no added parts needed.
It's a better deal.
Rangemaster audio interface is included. You are staring to sound like.....
Both the Rangemaster & the ProCaster include an audio (and power) interface, allowing you to use twisted pair for the long runs to the transmitter. The usefulness of this device is debatable. I used it for power on the Rangemaster, as it allowed me to plug in a wall wart without modification (such as cutting off the barrel end and attaching it to twisted pair. However, I was also using an Inovonics 222, which had wire terminals, and I had to bypass the interface for audio.
I see it as a convenience device, rather than a necessity. You should get a few conveniences if you're spending $700-$1,000.
wdcx wrote: You are staring ...
Generally, "staring" is considered to be impolite. Is that your objection?
From what I'm hearing I may not have had correctly organized information about the Rangemaster.
Here's what I plan to do to improve what I say in the future.
I will visit the website and review all the facts about the device.
Then I will return and post my corrected facts.
The ALPB will guide us all.
On Post # 9 in this AMT5000 Series of the forum, I announced plans to move from 1680 to 1640 kHz to get farther away from iBah splatter coming from 1700.
Tonight the frequency change was accomplished.
Spectrum Analyzer carrier readings were taken before and after so we could observe how much retuning will be needed.
I tested power at minimum, middle and maximum for both frequencies and note that there is a drop in relative power after the change.
Coming next - Retuning the AMT5000 for resonance!
Per instructions I peaked the output viewing at volt-meter, then turned C1 1-full-turn CW past that peak which made the voltage reading drop.
But on the Spectrum Analyzer 35-feet away the output actually INCREASED by 1 dBm!
I am running 180mW into the final.
I just want to make the rule thumpers uncomfortable.
I'll reduce it soon.
While the ASMT5000 is working perfectly at its new frequency of 1640 kHz, I am still hearing the sputtering static being mixed with my carrier.
What I believe is happening is that the iBUZZ digital noise generated at 1690, 1700 and 1710 kHz is being received on my transmitting antenna and mix-modulated in my 1640 carrier.
Last night during setup the offending iBUZZ station was off the air and I heard no such static.
Since the interference is being caused by a religious station, I pray to their God that He (they like to capitalize everything) blesses KDX (the One True KDX) by turning off the iBUZZ.