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Re: 5W mini transmitter for presetting the ATU
¿ªÔÆÌåÓýHi Alison,I used to use a Z-matches and they were good but FRI-match (PA0FRI) with printed toroids is much better! Wheatstone LED swr indicator very simple and effective. I do not even bother with a power meter, just check V and I on small metered buck. Of course I use silver plated wire-wrap wire and can get 5200 spots from hotel window in Vienna over 3 days. 73 Ross EX0AA On 18 Jan 2024, at 06:16, Axel Kohlgrueber <axelkohlgrueber@...> wrote:
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Re: 5W mini transmitter for presetting the ATU
Oh wow,
Now I have seen that all three ATU-100 tuners have the operating software set
to 3.2 when they were purchased. How can I now check whether the corresponding changes to the minimum input power
for tuning from 5W to 1W have actually been made? Do I definitely need this PicKit 3 programmer to read the hex file?
?
Do I have to reduce the 10 secondary windings on the tandem match transformer
to 5 windings each, or could it work like that? ?
Jeez... |
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Re: 5W mini transmitter for presetting the ATU
Oh dear Oh dear, you should always look closely!
I'm currently assembling the fourth ATU-100. I ordered the first three about 2 years ago, they still required 5 W for control and, according to the construction instructions, each had 10 secondary turns in the tandem match transformer. Then in July 2023 I ordered two more ATU-100 kits. They already have them changed minimum power for tuning start: 1 watt Unfortunately, I wound the Tandemmatch Transformer according to the old building instructions with 10 turns each instead of 5 each. Damn. But it's also good that I noticed it. So I'll change the transformer and everything should be fine. Or can I save myself that? |
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Re: 5W mini transmitter for presetting the ATU
On Thu, Jan 18, 2024 at 06:39 AM, Axel Kohlgrueber wrote:
Good morning,I just see that the currently delivered ATU-100 with program version 3.2 has already been changed to 1 watt input power for tuning. |
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Re: 5W mini transmitter for presetting the ATU
Good morning,
Yes, you have to somehow push the required power into the ATU-100 so that it rattles properly and quickly. A small transmitter with digital frequency setting would be ideal, regardless of whether there is a 2 x 27m dipole or an end fed for 20m attached, which sends the transmission signal to the ATU with 5 watts for 1-3 seconds. I will probably change the ATU so that it gets by with around 1W. In principle, it takes a bit of effort for me to pay €35 for a PICKit 3 programmer when the ATU-100 kit only cost €28. Can't you do the reprogramming without a programmer, e.g. with an Arduino uno, or Raspberry 4, or PC? Greetings everyone, DL5GT |
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Re: installed QMX Rev 2 diode mod, now it is deaf
k9pz
I think i didnt have my dummy load attached all the way.
Still lots of issues. I need to replace C508 and L503 at minimum. Any recommendations? I have 2 ceramic disk capacitors in parallel replacing C508 currently. L503 is damaged but seems to work? Maybe? Tx is half power on all bands. 80,60, and 40m are ok but rx is down 10db or so from before botched mod. 20 and 30m are terribly out of spec. |
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Re: QMX (hi band) new build does not power up
¿ªÔÆÌåÓýCan you tell if the 3V3 linear regulator is coming up? If it's
not, then the MPU won't come up and turn on power hold. On 1/17/24 11:58, 2e0gwb@...
wrote:
I built a QMX low band in the summer with no issues. So, I bought a high band kit for Christmas and after building it, I see nothing. No bootloader, no start, nothing on the display. Comparing the two, on the second build, there is nothing at all on the 3.3V rail, it draws about 8.5mA while pressing the left encoder to power up, then nothing when I release the button. Unwisely maybe, I tried substituting all the individual boards from the new build into the earlier main board, and everything works there, so it must be some sort of fault on the new main board. I can't see anyone else with this issue on the forum, has anyone else seen this? Advice welcomed, at the moment it's sitting there useless! -- Paul -- AI7JR |
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I have QDX high band and low band radios. Both assembled by QRP Labs. I noticed that the high band was not receiving many stations, and thought the band must be closing - over a month or so. Then I received the low band from Hans and tried it on 20 meters, and Wow, was there a lot of traffic. I started comparing the two on 20 meters using the same power supply (10 volts into 12 volt radios) and the same antenna.
Below are screen shots of the spectrum on JTDX for both radios, the low band first, then the high band. I next ran the RF Filter Sweeps for both radios and took screen shots, low band first, then high band Both are running on v1.10. This is the high band's filter sweep on 17M: Where should I start looking to fix this? Thanks, Don KD5NRO |
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Re: #qmx PTT Control
#qmx
Per,
I have exactly the same problem with my Rev 1 QMX build running firmware 014. I had good results running barefoot on Ft8 and thought I would try hooking up my QRP Labs 50W amp. Much to my surprise, I have a constant 5V on the ring of the PTT in receive or transmit. I too hope the next firmware release will fix this. 73, Pete, KH6GK |
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Re: QMX: almost zero power out all bands
Found the problem!
The Source leg to Q507 (an AOD403 MOSFET key shaper circuit) had not been soldered to the board during factory install of the SMD components. I hope this will not be an issue for other boards out there.? I enjoyed the troubleshooting process, despite the hassle. I determined the issue must be in the initial Tx stages and started looking there. Thanks for all the suggestions - it really got me thinking and looking. 73 Larry VE7EA |
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Re: Weak receive on QMX version 1 - New build
¿ªÔÆÌåÓýHave you looked at the sweeps to see how they look?73, Cliff, AE5ZA
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Weak receive on QMX version 1 - New build
I finally got around to building the version one QMX I purchased last year at FDIM.? The build went well and I thought I has no problems, but it appears to be weak on receive.
I have 4.95+ watts out on all five bands.? So it appears the transmit side is doing well. On receive I have been able to make contacts using FT8 mode, but on CW receive I can barely hear anything.? Anything I do hear is weak on the QDX,? but strong on a nearby receiver. Everything else seems to be working just fine. My firmware version is 1.00_014. The serial number of this unit is #62 so it was a very early unit purchased from Hans at QRP vendor night at FDIM. Anyone have an Idea where the problem may be with my receive problem? Gary A. - W0MNA |
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Re: 5W mini transmitter for presetting the ATU
Besides being amused by the hard way approach, some thoughts.
The test transmitter has to put out the needed power on all bands of interest.? ?Easier said than done for many. I has to be robust, you are going to expose it to terrible SWR while the atu100 tunes. Or course if it fails, your back up plan?? More important when in the field. It must be efficient if portable as its using your field power. IT should have switching to remove it out of line or you do a lot of cable swapping. I'd suggest small. Me I use a Zmatch with a bridge sensor and also power meter. -- Allison ------------------ Post online only,? direct email will go to a bit bucket. |
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Re: Precision IC socket - QMXable
The downside of the connector is to degrade the heat flow through the leads - a major element of the heat sinking.
A couple of days ago I noticed power out dropped to 2W.? It took one hour to open the unit, separate the boards (I made extender cables to allow operation with separated boards) find the hot BS170, replace it and reassemble the QMX. I do have a vacuum de-soldering station that makes removal easy. |
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QMX (hi band) new build does not power up
I built a QMX low band in the summer with no issues. So, I bought a high band kit for Christmas and after building it, I see nothing. No bootloader, no start, nothing on the display. Comparing the two, on the second build, there is nothing at all on the 3.3V rail, it draws about 8.5mA while pressing the left encoder to power up, then nothing when I release the button. Unwisely maybe, I tried substituting all the individual boards from the new build into the earlier main board, and everything works there, so it must be some sort of fault on the new main board. I can't see anyone else with this issue on the forum, has anyone else seen this? Advice welcomed, at the moment it's sitting there useless!
George, M0HLP |
Paul - AI7JR
Bruce Akhurst
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