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Post by Deleted on Apr 28, 2017 22:23:21 GMT
More Answers to Jim's Questions
POWER
Let's take advantage of the work you have done, Jim, having installed a 120 VAC power line out to the transmitter location.
Make it simple. Connect the supplied AC-to-AC Wall Wart and plug the existing power connector to the power jack on the back of the AMT5000.
IGNORE all our previous talk about various power options;
IGNORE the power input screws on J5... leave them empty!
IF we discover that hum from the AC line is inducing its way across to the audio line we can start a new discussion of power options, beginning fresh.
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Post by Deleted on Apr 28, 2017 22:36:55 GMT
One More for Now
Jim asked: "Can't I just run the Cat5E Solid STP cable from the computer out to the transmitter?"
Unfortunately I am not conversant with the cable types by their descriptions and do not know the answer to your question.
As far as the differences between running un-balanced cables at consumer level (-10dB) VS balanced cables at professional level (+4 dB) - perhaps I should mention that in EITHER case I believe the cables should be shielded. If the cable is balanced I believe the 2 inner conductors should be "twisted pair".
Other than that, I have already given a detailed description of what I recommend and what I believe you can expect by way of result.
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Post by jimhenry2000 on Apr 29, 2017 16:37:23 GMT
Carl, CAT5E is a specification of LAN cable. STP=Shielded Twisted Pair, vs UTP which is unshielded twisted pair. It is 4 pairs of twisted conductors. STP has an additional uninsulated conductor plus a foil shield. One More for NowJim asked: " Can't I just run the Cat5E Solid STP cable from the computer out to the transmitter?" Unfortunately I am not conversant with the cable types by their descriptions and do not know the answer to your question. As far as the differences between running un-balanced cables at consumer level (-10dB) VS balanced cables at professional level (+4 dB) - perhaps I should mention that in EITHER case I believe the cables should be shielded. If the cable is balanced I believe the 2 inner conductors should be "twisted pair". Other than that, I have already given a detailed description of what I recommend and what I believe you can expect by way of result.
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Post by Deleted on Apr 29, 2017 17:46:20 GMT
CAT5E STP Cable
J.H. describes the cable: "CAT5E is a specification of LAN cable. STP=Shielded Twisted Pair, vs UTP which is unshielded twisted pair. It is 4 pairs of twisted conductors. STP has an additional uninsulated conductor plus a foil shield."
What a versatile cable with spare room for later uses!
It should give you all the options you need for trying connections and changing them later if you decide to do so.
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Post by jimhenry2000 on Apr 29, 2017 20:50:23 GMT
Well I shut down the transmitter and brought the antenna and coax down. That's probably all I'm good for in today's heat. CAT5E STP CableJ.H. describes the cable: " CAT5E is a specification of LAN cable. STP=Shielded Twisted Pair, vs UTP which is unshielded twisted pair. It is 4 pairs of twisted conductors. STP has an additional uninsulated conductor plus a foil shield." What a versatile cable with spare room for later uses! It should give you all the options you need for trying connections and changing them later if you decide to do so.
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Post by jimhenry2000 on May 3, 2017 3:46:16 GMT
Today I received the audio amplifier Carl recommended, though I would still have to buy or fabricate a power supply if I decide to use it. First I am going to try to connect the audio output from my PC to the "Professional audio source" inputs on the AMT-5000, without the amplifier, since the manual doesn't mention the need for an amplifier. Hopefully I will get this done tomorrow (Wednesday) and we'll see what happens.
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Post by jimhenry2000 on Jun 1, 2017 1:23:02 GMT
I am getting very frustrated with the AMT-5000, though I don't think it's the transmitters fault. Today I went out to check out and hopefully improve the grounding system. I discovered two of the 20 ground radials had become disconnected from the ground ring so I re-soldered them. I added another 8' ground rod right under the antenna. It's only 4' in the ground so far. I've been pounding away with a 4 lb. drilling hammer until my arm felt it might fall off. I'll continue with that tomorrow but it is now connected to my grounding system. The original ground rod is still connected also but is about 100' away. I re-peaked the transmitter first with a dummy load then with the antenna attached. Now my range is even less than before! In case anyone can offer insight here are my observations: Gain, Modulation, and limiter set fully counter-clockwise for tuning, and RF power control set to mid-range for the tuning procedure. When adjusting C1 I get virtually zero change in RF input current, typically about 0.16v on my DMM. This is the case with both the dummy load and the antenna, and using about 5 different coil taps. Adjusting the RF power control up I am still able to reach 100 mw, with RF Input current hitting 0.29v and RF Input voltage of 5.2v.
The next problem is when I rotate the gain control fully clockwise my audio feed can be heard on my monitor radio but is very low. Rotating the modulation control fully clockwise makes zero difference. Rotating the Compression control fully clockwise does make a difference and it needs to be almost fully clockwise to sound decent on my radio, which is RIGHT NEXT TO THE TRANSMITTER AND ANTENNA.
It seems to me part of the problem is with the audio feed. I have checked the RDL STA-1M line amp and confirmed the connections are all good, and the gain is set to the max. I haven't taken down the audio cable to check continuity but I did do that pre-install, plus if there was a problem I assume I would get no input signal to the xmtr at all, which is not the case. Any ideas?? Tomorrow I am swapping out the 5000 and installing the ProCaster and hoping for better results.
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Post by Deleted on Jun 1, 2017 1:39:03 GMT
Thinking It Through
Jim, from your description it seems you are having poor results from both the RF peaking and the audio level.
My brain is overflowed right now so many things are going on, but I will keep thinking about it.
You should independently verify that the RDL Line Amp is providing audio in the +4 dB range. That level should hold at both ends of the long audio cable. Think of it as a telephone line designed to carry a specified audio level.
At last report you were using the supplied wall-wart power supply plugged into your outdoor 120 VAC line that you installed.
Is it true that in at an earlier time you were getting better results?
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Post by jimhenry2000 on Jun 1, 2017 2:00:23 GMT
Carl, Yes there were times when I was getting better results. My signal barely reaches from the house to the street now, which is about 800-1000 ft. Any idea how I can measure the audio signal, with either a DMM, VOM, or VTVM? I am still using the 120 vac power source but I will do away with that with the ProCaster. Thinking It ThroughJim, from your description it seems you are having poor results from both the RF peaking and the audio level. My brain is overflowed right now so many things are going on, but I will keep thinking about it. You should independently verify that the RDL Line Amp is providing audio in the +4 dB range. That level should hold at both ends of the long audio cable. Think of it as a telephone line designed to carry a specified audio level. At last report you were using the supplied wall-wart power supply plugged into your outdoor 120 VAC line that you installed. Is it true that in at an earlier time you were getting better results?
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Post by Deleted on Jun 1, 2017 2:37:32 GMT
Measuring the AudioWithin your computer generate a continuous tone at 0 dB (maximum level) on the audio software graph... make it 30-minutes or long enough so it won't keep running short. The following link is all about line levels and you'll easily spot the Line Levels given in 3 different AC measurement scales. LINE LEVELS LINKThe Professional Audio Level is what you want to see on the balanced line output from the RDL Line Amp, reading across the +/- lines. If the shield (ground lead) of your long balanced line isn't connected to anything at either end of the line, try connecting it at the transmitter end to the GND terminal of J5..
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Post by jimhenry2000 on Jun 1, 2017 4:07:44 GMT
The shield of the audio line is connected at the transmitter side but not at the other side. I will have to read that article to try to figure out what else you are talking about. I have no idea how to generate a continuous tone or any other tone on the PC. Measuring the AudioWithin your computer generate a continuous tone at 0 dB (maximum level) on the audio software graph... make it 30-minutes or long enough so it won't keep running short. The following link is all about line levels and you'll easily spot the Line Levels given in 3 different AC measurement scales. LINE LEVELS LINKThe Professional Audio Level is what you want to see on the balanced line output from the RDL Line Amp, reading across the +/- lines. If the shield (ground lead) of your long balanced line isn't connected to anything at either end of the line, try connecting it at the transmitter end to the GND terminal of J5..
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Post by Boomer on Jun 1, 2017 5:59:59 GMT
You can generate tones in wave editors like Cool Edit, Audition, Audacity, Sound Forge and others I'm sure.
Usually a menu option will offer a Generate applet if you click on it. It will ask what frequency to produce, select 1000 hz, a standard tone, Sine, and for 30 minutes, click okay and your editor's display should be filled with the waves. Push play and there's your tone.
You don't have to save it, just play it, but you can save it to a convenient file, like "1000 hz.wav", for testing media players, transmitters and other things.
I often do this, because when you're in test mode as you are, music or speech is not the best, the variations of levels between files can fool you.
Boomer
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Post by Deleted on Jun 1, 2017 13:42:15 GMT
Tone Soon to Come
Jim Henry says: "I have no idea how to generate a continuous tone or any other tone on the PC."
We can fix that! And it gives us a good idea of a service the ALPB can offer here on the forum!
Today we will generate a test tone and post it here IN THIS THREAD!
Anyone who needs a reference tone can get it right here.
Watch for that, coming today, June 1st, from ALPB.
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Post by Deleted on Jun 2, 2017 1:57:02 GMT
Tone Tomorrow
It's after dark now, not a time for testing long wires out in the night.
I'll be back tomorrow with the promised Reference Tone.
And now, Our National Anthem.
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Post by jimhenry2000 on Jun 2, 2017 2:01:40 GMT
Well for now, I have retired the AMT-5000. Down the road, I will build it into the heavy duty strand-mount Nortel enclosure but for now I'm pinning my hopes on the ProCaster. See new thread. Tone TomorrowIt's after dark now, not a time for testing long wires out in the night. I'll be back tomorrow with the promised Reference Tone. And now, Our National Anthem.
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