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Post by jimhenry2000 on Mar 10, 2017 6:18:55 GMT
I am making some progress. I now have an external xmtr enclosure but not ready to use it until I have a handle on how the 5000 is performing.I now have a 102" whip on a 25 foot telescoping fiberglass tower but so far I am not getting better performance than the factory config with both xmtr, long wire antenna, and ground wire inside. The external antenna is grounded to an 8 ft. groundrod that also grounds my home's backup generator. THe antenna goes back to the xmtr via 50ft 50 ohm coax. Currently the male lead of the PL-259 is just connected to the transmitters long antenna lead via an alligator clip. The coax shield is only grounded to the afore mentioned ground rod. The transmitter's long ground lead is still connected to the ground of its electrical outlet. Range is no better than the original factory set up and possibly worse. Someone here sent me a ton of links from part15.us which I printed and read throroughly but that mostly mentioned conecting the 5000 to an ISOTron but that is a long way off for me. Not sure what to do at this point. Any suggestions? On the bright side my township has embraced the idea and have already sent me several PSAs they would like me to broadcast.
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Post by station8 on Mar 10, 2017 17:24:44 GMT
Howdy Jim: I'll give you some ideas and hope it helps out. 1) Before you ever let people know your putting a station on the air please do testing first ! Just so you can iron out problems and issues. 2) I have 25 am tx here and I done various testing with different tx and different antenna on each units. And I can tell you from my experience you need to build the antenna for the tx otherwise your range will be bad ! Now using that 102 inch whip, Get rid of it it's not worth bothering with in my opinion. Now sstran made an antenna for the 3000 you should be able to use that antenna on the 5000 as well Here is the site www.sstran.com/pages/sstran_buildant.htmlHere is a range test the guy did on his sstran 3000 it will give you an idea what you can get with the Right antenna and setup OK. I do have the sstran 5000 myself and haven't got a perfect antenna for it yet do to im not a fet output Fan because every transmitter I have I don't like the way they preform personnaly. I could tell you more but would be easy to discuss on teamspeak and you could ask me anything then Or we could ask Carl if we could do a show on this topic and have several people to ask me question On the show what do you think?. NOTE: NOT one transmitter will work with same antenna this is what I found out in my testing ! I do have issue with this site a times so its hard to get with people. Have a great day station 8 ( Mr antenna man )
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Post by Deleted on Mar 11, 2017 1:36:14 GMT
Something Doesn't Sound Right
In the opening post Jim Henry said: "The external antenna is grounded to an 8 ft. groundrod."
Do you really mean that? Literally?
The antenna should not be grounded.
The transmission line shield from the transmitter can be grounded...
Or, a solid wire from the ground-side of the transmitter circuit can be run to the ground rod.
But the RF output coming from the loading coil is connected exclusively to the antenna.
MORE -
The groundrod in the earth makes for good electrical safety but will not do much to enhance range.
Range requires ground radials.
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Post by Deleted on Mar 11, 2017 2:04:24 GMT
Added Thought
Another advantage of grounding the AMT5000 to the ground rod WITH AS SHORT AND HEAVY WIRE AS POSSIBLE to keep the impedance as low as possible in the ground lead... it puts the transmitter in the right range to follow the tuning instructions and get the best results. But even when the transmitter is properly tuned into the antenna system, ground radials are still necessary to increase range.
After adding ground radials, the transmitter will need to be re-tuned.
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Post by jimhenry2000 on Mar 11, 2017 2:20:59 GMT
Carl, What I meant is that the antenna MAST is grounded to the 8ft. ground rod. At this location I do not have room for radials, HOWEVER, if radials can provide a benefit in range when they are not directly below the antenna, then I have options. I CAN set up a ground system with multiple radials but it might be as much as 100 ft. distyant from being directly below the antenna. Something Doesn't Sound RightIn the opening post Jim Henry said: " The external antenna is grounded to an 8 ft. groundrod." Do you really mean that? Literally? The antenna should not be grounded. The transmission line shield from the transmitter can be grounded... Or, a solid wire from the ground-side of the transmitter circuit can be run to the ground rod. But the RF output coming from the loading coil is connected exclusively to the antenna. MORE - The groundrod in the earth makes for good electrical safety but will not do much to enhance range. Range requires ground radials.
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Post by station8 on Mar 11, 2017 2:34:11 GMT
Howdy: Here some more info Jim.
1) You should NOT run a 50 ohm cable at 50 foot, This is one problem. I have found in my testing going behind about 40 foot your loosing range and the rf output to the Antenna.
You just can't hook up a 50 ohm cable direct to your tx without knowing The proper output impedance of the tx.
This is the reason why your loosing range!
With very low power you need to find ways to keep from having rf loss and It does make a big difference in what you do.
I did make my sstran 5000 go 2 mile without a ground system with the antenna base was 6 foot off Ground level.
So it can be done.
Hop this help station 8
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Post by Deleted on Mar 11, 2017 3:36:09 GMT
Specialized Technology
Jim Henry's circumstances: "if radials can provide a benefit in range when they are not directly below the antenna, then I have options."
There was an extended discussion of off-center or off-set radials over at part15_us but I only remember one thing that was said... the pattern of the omni-directional signal will be warped more toward one direction than another.... it would be good if we could locate that thread from months or a couple years ago.
Jeff Station8 brought up an important thought that I overlooked from Jim's opening post... the 50-foot coax transmission line. It will change the characteristics of the tuning and the resulting signal, and again this has been the subject of past posts but something with which I have had no experience.
I do want to run tests with transmission lines so I can keep transmitters indoors with antennas outdoors.
I think you need to bring these questions over to part15_us.
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Post by jimhenry2000 on Mar 11, 2017 4:18:27 GMT
Station 8, Thanks SO MUCH for your responses. I am aware of the plans on the SSTRAN site for the base loaded coil antenna. I just always thought that was strictly for the AMT-3000, not the AMT-5000. Anyway, I already DO own an ISOTRON 200B antenna. I'm just thinking I want to experiment with the 102" whip before I go to the ISOTRON. SO, it seems like very many people use a 102" whip, so what is the problem with that? Also from what I have read, I assume that I need to do SOMETHING to re-tune the xmtr circuit to match the 102" current antenna. Also, I am currently fine with getting rid of the 50 ohm coax and just using a good copper lead, say AWG 12ga stranded?? I welcome all input!! Howdy: Here some more info Jim. 1) You should NOT run a 50 ohm cable at 50 foot, This is one problem. I have found in my testing going behind about 40 foot your loosing range and the rf output to the Antenna. You just can't hook up a 50 ohm cable direct to your tx without knowing The proper output impedance of the tx. This is the reason why your loosing range! With very low power you need to find ways to keep from having rf loss and It does make a big difference in what you do. I did make my sstran 5000 go 2 mile without a ground system with the antenna base was 6 foot off Ground level. So it can be done. Hop this help station 8
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Post by station8 on Mar 11, 2017 5:39:33 GMT
Howdy you all: Jim I'll try to answer some information for you, But I will need info from you.
1) What kind of range you want ?
2) How high are you ? Example 2 story house or ground level
3) Setup of your tx site ?
I never was a fan of the 102 inch whip antenna,Its just me.
If you want to use the 102 inch its fine,But you should use the internal 5000 coil Then take some solid copper wire shorter the better and hook it up to the antenna & tx And tune for max reading and should be fine.
I have used stranded wire vers. Solid copper wire and got better performance out of Solid copper wire in my test !
As for the isotron I have heard different range result on that antenna with different tx So you will have to test and see what you get for range.
I can tell you from experience part 15 works different then the real broadcast stuff It either works or don't work!!
And you won't know your range until you do a drive test and I know this from fact after doing over 30 antenna Test with various tx test!!
Now when using the antenna for the sstran 3000 on the 5000 make sure you bypass the internal Coil due to the base coil on the antenna that is your manual atu for tuning the antenna correctly!
It be easy to talk on alpb team speak to help you out better. Then I could tell you everything I know.
I hope this help you out more.
Have a great day station 8
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Post by jimhenry2000 on Mar 11, 2017 9:11:15 GMT
Also that groundrod is smackdab in the middle of an asphalt driveway making radials not practical there. Something Doesn't Sound RightIn the opening post Jim Henry said: " The external antenna is grounded to an 8 ft. groundrod." Do you really mean that? Literally? The antenna should not be grounded. The transmission line shield from the transmitter can be grounded... Or, a solid wire from the ground-side of the transmitter circuit can be run to the ground rod. But the RF output coming from the loading coil is connected exclusively to the antenna. MORE - The groundrod in the earth makes for good electrical safety but will not do much to enhance range. Range requires ground radials.
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Post by jimhenry2000 on Mar 11, 2017 9:13:05 GMT
I can easily replace the 50ft. coax with 50ft. of AWG #12 stranded copper. Howdy: Here some more info Jim. 1) You should NOT run a 50 ohm cable at 50 foot, This is one problem. I have found in my testing going behind about 40 foot your loosing range and the rf output to the Antenna. You just can't hook up a 50 ohm cable direct to your tx without knowing The proper output impedance of the tx. This is the reason why your loosing range! With very low power you need to find ways to keep from having rf loss and It does make a big difference in what you do. I did make my sstran 5000 go 2 mile without a ground system with the antenna base was 6 foot off Ground level. So it can be done. Hop this help station 8
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Post by station8 on Mar 11, 2017 11:09:47 GMT
Howdy all: Jim I'll explain more.
Jim what is your back ground in this stuff ?
1) You can NOT run a 50 foot hot transmission line.
I'm keeping it simple !!!!
Here is the reason ,100 mW is not allot of power and by the time the rf power reaches the antenna Specially with a mismatch antenna and a long transmission line (50 feet)with a NO gain antenna you Have NO rf going into the antenna and out into the air wave.
And this is why you have NO range at all !!!!
This is a waste of time and money to do in this kind of setup !!!!!!!!
We really need to talk on the ALPB teamspeak so you can write down some notes that I'll tell you
And get a better understanding of what I'm trying to say and you can ask me question.
So we can start fresh
Have a great day station 8
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Post by Deleted on Mar 11, 2017 12:47:31 GMT
Morning Thoughts
These are "guesses" by a guy with "some experience" but are not definite "science"...
I would stick with the coax cable. Whether the "50-ohm" rating of the cable plays a role either positive or negative in this application is unknown, since the actual source and termination impedances are not in the 50-ohm range.
The coax cable will deliver the RF to the antenna without itself radiating, it may radiate somewhat, but in general will deliver the RF out to the antenna.
An open (unshielded) wire used as a transmission line will radiate and in effect become part of the antenna.
If there is a transmission-line loss of RF power it can be compensated by increasing the output power with the control provided on the AMT5000 circuit card.
Although some persons claim a 102" whip works better/worse than a plain wire, I believe the two are electronically the same and that either type works as well as the other.
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Post by station8 on Mar 11, 2017 13:41:13 GMT
Howdy all: I will explain.
NOTE: I can say this do to I done this test first hand !!
Carl You can NOT run long antenna or transmission lines on part 15 type transmitters !!!!
I have done the experiment on the talking house 5.0 / sstran 5000/ Etc.
And found going over 25 feet of coax cable I started notice rf output drop then I went to 30 feet coax cable And saw more drop then I went to 40 feet of coax cable it was really bad !
I used low loss coax cable in test/heavy shield.
Now I test each tx with a short antenna and did drive test and took notes.
Next I place a 50 foot copper stranded wire antenna and did a drive test and took notes.
In my findings I have found the short transmission line as well a short antenna you preformed great !!!
Now with a long transmission line and short antenna you had loss and your range decreased big time !!!!
Now with a long antenna and long transmission line it was crap in range and NOT worth talking about It was so bad !!!!
And in testing i even turning up the power more did NOT help at all when using long antenna and long Transmission line !!!
Now turning the power up on short antenna and long transmission line I did NOT see much improvements !!!
When I do testing personally i look and try everything I can think of to make failures and gain !!!
The only way to get good range is to keep transmission lines short due to loss !!
And also to build the right antenna for that tx other wise you will have range issues !!
And you need to build an antenna with gain as well !!
Have a great day station 8
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Post by jimhenry2000 on Mar 12, 2017 6:21:39 GMT
Perhaps I should wait to speak to station8 on Teamspeak after all. This forum leaves much to be desired. I attempted to respond to each of station8's questions but my responses disappear before I can go on to the next question.
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