Hi, Daniel.
Not enough power for tuning. Use 10W or 20w.
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Re: ATU-100 display artifacts
Hi, Tony
Bad display. Change it.?
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ATU-100 display artifacts
Hi,
I've just taken delivery of an ATU-100 from one of the Chinese online marketplaces, it looks really nicely built, looking at teh inside PCB,? the soldering looks very good as does the general build and toroid winding.
But,.... for some reason, the oled seems to suffer with a lot of display corruption whilst tuning, from powerup, the display is perfect, but putting just 1 watt into the tuner from the IC-705 causes various pixels or portions of the display to either go out, or other pixels to illuminate making the actual text very much unreadable.
For example, I often get a single pixel wide horizontal line beneath either the RF power value, or the SWR value or sometimes through the actual numbers, then other times I get part of the battery symbol missing or the word SWR will be missing part of the S.
Oddly, after first powering on, the display is always perfect.
I have tried all firmware versions going from 1.2 to 1.6 and exactly the same thing happens with each version.
Anyone else had anything like this, I am suspecting a faulty Oled, but it does work fine after every power up until I actually put RF in to start the tuning process.
The tuner seems to tune perfectly on every band with a relatively short radiating element and counterpoise wire attached to the ground terminal.
Regards
Tony.
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It sounds like your installation may be radio-coax-ATU-coax-xfmr-antenna? If not, full details would be most helpful.
If so, how long are the coax runs and how is your counterpoise deployed?
Al
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Hi Al.
I always tune at 5 watts or so, never at full power.
I’m not sure what you mean about getting rid of the transformer and connecting the wire directly to the ATU … but maybe you mean removing the 67’ antenna wire from the transformer box and connecting it directly to the ATU? ?Unfortunately that’s not possible since my EFHW transformer box is on the side of the 3rd floor of my house, and the antenna wire goes from there up into the trees out back. ?I have a friend willing to climb up there, but not very often.
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On Feb 8, 2023, at 10:11, Al Scanandoah < k2znqrp@...> wrote:
Try getting rid of the transformer and just connect the wire directly to the ATU. Also, if you haven't already done so, see if you get different tune results at reduced power.
Al
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Try getting rid of the transformer and just connect the wire directly to the ATU. Also, if you haven't already done so, see if you get different tune results at reduced power.
Al
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Hi Marek.
I tested the ATU-100 by connecting it to my radio and antenna. ?I don’t have a dummy load, but a friend does, so I will go through the tests you mentioned. ?I’m completely new here and really don’t know what I’m doing. :)
My EFHW unfortunately does not give low SWR on all bands — only 40 & 20 are useable. ?15 & 10 have SWR > 3 for the entire band. I’m not sure what the problem is there.
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On Feb 8, 2023, at 04:59, Marek SP9TKW < sp9tkw@...> wrote:
How did you validate that ATU works properly??
I used following method
- connected 50ohm dummy load and checked that I get 1:1 on all bands at 10, 20, 50, 80 and 100W
- connected 100ohm and then 200ohm dummy load and checked again if I get 1:1 on all bands with the same power settings as above
- during theses test I also verified that power displayed corresponds to power set. I allowed for 5% error.
After these tests were all OK, I took 12,5mtr (41feet) long wire with 9:1 UnUn and 5mtr (17feet) counterpoise and tested ATU. On all bands from 80-10 I get SWR <=1.5:1
Your EFHW should not require ATU, as it should give SWR <=1.6:1 on all bands except 10m. Of course if you want SWR even lower then ATU is needed as well as WARC bands.
GL 73 Marek
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How did you validate that ATU works properly??
I used following method
- connected 50ohm dummy load and checked that I get 1:1 on all bands at 10, 20, 50, 80 and 100W
- connected 100ohm and then 200ohm dummy load and checked again if I get 1:1 on all bands with the same power settings as above
- during theses test I also verified that power displayed corresponds to power set. I allowed for 5% error.
After these tests were all OK, I took 12,5mtr (41feet) long wire with 9:1 UnUn and 5mtr (17feet) counterpoise and tested ATU. On all bands from 80-10 I get SWR <=1.5:1
Your EFHW should not require ATU, as it should give SWR <=1.6:1 on all bands except 10m. Of course if you want SWR even lower then ATU is needed as well as WARC bands.
GL 73 Marek
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My EFHW has a 13’2”~ counterpoise. I don’t know about grounding the ATU — will have to read that page - thanks.
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On Feb 7, 2023, at 11:18, Al Scanandoah < k2znqrp@...> wrote:
Is the ATU well-grounded or does it at least have a suitable counterpoise? RF could be getting into the ATU's circuitry.
Here's a good read:?
Al
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Is the ATU well-grounded or does it at least have a suitable counterpoise? RF could be getting into the ATU's circuitry.
Here's a good read:?
Al
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I have done some more experimentation here. ?My EFHW should work on 15m, but 15m has high SWR on my install. ?Not sure why the EFHW has high SWR on 15m, but the tuner should be able to pull it in -- it pulls it in at 2.94, which would seem to be too high. ?On this EFHW, 17m “tunes” to 2.86. ?Is this what I should expect? ?I thought it should tune to somewhere between SWR of 1-2.
Again, I’m the new guy, never had a tuner, so I don’t really know what to expect, but everyone tells me that SWR of >2 is too high.
Thanks.
Daniel
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Hi, all.
I finally got my ATU-100 built over the weekend, and I tested it the other day with my 40m-10m EFHW. ?Because it’s an EFHW, I didn’t really know what to expect (I wasn’t sure it would be able to pull in the other bands), but it seemed to do okay. ?Then, later, when I actually tried to use it, it showed garbage on the display. ?Today it isn’t showing garbage, but it doesn’t seem to want to tune either.
I learned from this guy —??— that the proper operation is to short-press the button to reset the device, then long-press to enter tune mode. ?I have tried tuning on SSB while talking, on AM while talking, and on FM while not talking. ?(I would think that AM would not require me to talk either, but I’m the new guy here and don’t really know what I’m doing.)
Anyway, it seems to stay in tune mode now, not fully tuning any bands.
Three questions: 1- I assume there is a lot of user error here; am I doing this right? 2- my green button (exactly like the one in the video) is broken; any idea where I can get a suitable replacement? 3- did I maybe fry something on the tuner?
Constructive feedback welcome.
Thanks.
Daniel
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Re: Automatic vs Manual ATU
Not sure what your comment about ATU placement has to do with it's ability to tune without RF applied. Perhaps folks could be of more assistance if you could define the problem you're trying to solve.
Al
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Hi, all.
I finally got my ATU-100 built over the weekend, and I tested it the other day with my 40m-10m EFHW. ?Because it’s an EFHW, I didn’t really know what to expect (I wasn’t sure it would be able to pull in the other bands), but it seemed to do okay. ?Then, later, when I actually tried to use it, it showed garbage on the display. ?Today it isn’t showing garbage, but it doesn’t seem to want to tune either.
I learned from this guy —??— that the proper operation is to short-press the button to reset the device, then long-press to enter tune mode. ?I have tried tuning on SSB while talking, on AM while talking, and on FM while not talking. ?(I would think that AM would not require me to talk either, but I’m the new guy here and don’t really know what I’m doing.)
Anyway, it seems to stay in tune mode now, not fully tuning any bands.
Three questions: 1- I assume there is a lot of user error here; am I doing this right? 2- my green button (exactly like the one in the video) is broken; any idea where I can get a suitable replacement? 3- did I maybe fry something on the tuner?
Constructive feedback welcome.
Thanks.
Daniel
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Re: Automatic vs Manual ATU
An ATU should always, always, always be placed at the antenna feed point, not, not, behind the txrx.? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Returning to my good, old , remote motor controlled? Z match. Nothing can beat that? on rx?
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Re: Automatic vs Manual ATU
Eh? the match is between the AMU and the Tranciever not the AMU and the aerial
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On 07/02/2023 13:17, Paul Decker wrote: Put your antenna on the input side (where the Transceiver goes), and your antenna analyzer on the antenna side and see if it is still matched.
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Re: Automatic vs Manual ATU
An easy way to tell is, after the ATU is matched, when you switch between TX and RX, is there any relay clicking that indicate TX/RX changeover relays?? If not, it's highly likely it's using the same matching network for RX.
Another way to tell is to simulate RX.? Put your antenna on the input side (where the Transceiver goes), and your antenna analyzer on the antenna side and see if it is still matched.? ?
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Re: Automatic vs Manual ATU
My SGC239 auto tuner says that you tx first, get a good match , key up-you receive. But it does not say that the tx match is the same as an rx match
Conclusion: going back to my Z match with remote motor control?
Amen
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Re: Automatic vs Manual ATU
An ATU matches the impedance of the load with the impedance of the source.
On TX, the antenna is the load and the transmitter is the source.
On RX, the antenna is the source and the receiver is the load.
With "traditional" ATU's as we are familiar with, it just so happens matching TX also matches RX.
It's 100% possible to construct an ATU that can match in the RX position by using a sensitive noise bridge and selecting the receiver to receive a signal, then match for greatest RX signal strength.?
I've actually worked on and used a system which worked that way, the purpose was to silently tune before actually transmitting a covert burst transmission.?
On 02/06/2023 8:20 AM howard winwood G4GPF <winwoodh@...> wrote:
Simply put, an auto atu can ONLY tune a TX, BUT once tuned will enhance receive as the antenna will be tuned for both TX and RX.
An auto atu CANNOT tune an antenna for receive.
I have made this question to various people, and many dont agree!!!!!
The auto atu needs an error swr voltage, which is missing on rx !
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Re: Automatic vs Manual ATU
Who advised you that an ATU can match an antenna without any RF excitation, and did these people provide the physics-defying data to support those claims?
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Re: Automatic vs Manual ATU
Simply put, an auto atu can ONLY tune a TX, BUT once tuned will enhance receive as the antenna will be tuned for both TX and RX. An auto atu CANNOT tune an antenna for receive.
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I have made this question to various people, and many dont agree!!!!!
The auto atu needs an error swr voltage, which is missing on rx !
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Al Scanandoah
mike