开云体育

Sorry for all the questions, I thought I had everything working, but now when I open the measurements screen and press the button, nothing happens. It will do an SWR scan with the Serial interface but not just show when you press tune.

Please comment. I'm thinking of investigating linear operation at reduced power, possibly up to 25W (~16v PS). Determine if it is necessary to be able to control PA bias currant individually. My test approach would be to test the PA linearity without a LPF (Lift thee LPF input capacitor and inductor and couple to a 50 ohm dummy load. Excite PA with low level and observe output with scope and spectrum analyzer as bias current is increased If linear operation cannot be obtained with reasonable bias due to mismatched IRF510s then provide for individual bias circuits.

Hi Hans and Group, Is there still the possibility that the SSB internal microphone can be made to work? I am not in a hurry, but I am unclear on that score. George K3GK

I have FW 1_01_03 FW loaded on my QMX+ but am seeing problems with seeing any GPS plots when i have logged into Putty and checking the GPS Viewer. The System config - GPS source is set to QMX+ Internal. Is any one else with the Beta firmware having any issues with GPS?

Finally after waiting 2 weeks to get a suitable Mic set up, today is the day. Was very impressed by the QMX+ setting itself up to make SSB. Tomorrow I go on air to test it out. Using the dummy load to test I only found one undesirable trait. Noted a spluttering on the audio that sounded a bit like RF feedback into the Mic input. However discovered that this was caused by activating "Mic noise cancelling". Left it disabled for now, thinking possibly phasing issue between internal and external mic? Incidentally the mic is a Chinese one for the usdx......I disconnected the internal speaker and corrected the wiring to suit. de VK6XT

I just finished building a QDX board version 3 with the latest 1.10 firmware installed and have been testing it. I built it for 9v operation and am using a variable bench power supply to test it. I have made a few FT8 QSOs on both 40m and 20m, I am noticing the power starts out at about 4w and slowly drops to about 2w by the end of the FT8 transmission cycle. The voltage from the power supply is a rock solid 9v. The current draw on transmit starts at about 1.02 amps and drops to about .4 - .5 amps by the end of the transmission cycle. Is this normal and if not, what should I be looking at? 73 Doug WB5WRC

Installing the new SSB operating software on the QMX+ worked right away. Initial setup was completed without any instructions. Impressive work from the developer! By the way: You can see how to quickly dismantle a 20m antenna mast here. :) https://www.facebook.com/share/v/1EbbHBmeX6/

The output on the upper bands seem a bit weak on my QMX+. Is there a tutorial on tuning up the QMX+ like you can the QCX?

I know its a little cheeky but any idea how long to an update. None of my QMXs will calibrate and I have to turn the pre phase and amplitude off.

A new chat has been created: All, I've built the QMX rev 4 60-15m transceiver. I've ran all the terminal test and analysis sweep with positive results. I've even made an FT8 contact on 15m, and CW contact on 20m. However, the radio has had a behavior repeated multiple times that I don't know where to start to investigate. When I reach over to adjust a knob, push a button, or simply touch the case, the radio's screen will loose all characters, and audio will go to a loud hiss. Powering off and then on resolves the issue. The issue has repeated itself possible 8 to 10 times over the past ~10 hours of on time. Any ideas on what might be causing the issue, and/or how to resolve. Regards, Wilson Little (NT5AT) By: NT5AT - Wilson <wilsonlittle66@...> View/Join This Chat Do not reply to this message to post to the chat. You can participate in chats only through the group's website.

I suspect that my factory built QMX has a blown BS170. I was running FT8 on 15m into a resonant antenna tuned with an external SWR analyzer. The rig measured the SWR at 1.26:1. I don't believe that the SWR changed at all during the operation. I checked it again when I noticed the power drop, both on the rig and with the external meter. It was still about 1.26:1. I think I can rule out high SWR. Here is a list of output powers that I measured when new with the battery, as recorded at the factory, and after the failure: 20m has 3.7 watts on Talentcell battery (Factory 3.8 watts) (After the failure 2.2 watts) 17m has 4.5 watts on Talentcell battery (Factory 4.5 watts) (After the failure 2.2 watts) 15m has 4.7 watts on Talentcell battery (Factory 4.6 watts) (After the failure 1.9 watts) 12m has 3.5 watts on Talentcell battery (Factory 3.4 watts) (After the failure 1.9 watts) 10m has 3.8 watts on Talentcell battery (Factory 3.6 watts) (After the failure 2.0 watts) I use a dummy load and a mini QRP Power Meter like this one to measure power: https://www.aliexpress.com/item/1005003913071532.html I use a Talentcell YB1203000 (12v, 3Ah) battery which my DVM is measuring 12.3v fully charged. Could it be that the extra 0.3v is too much for the BS170's especially on higher frequencies? If so, would a "DROK DC-DC Adjustable Buck Voltage Converter Stabilizer 6-32V to 1.25-32V LCD Display Constant Volt Amp 6V 12V 24V Step Down Voltage Regulator Power Module" prevent future failures if I reduce the voltage to 11v? I've read about the addition of a couple of zener diodes (1N4756A) to the BS170s of QDXs. Would this also provide protection on the QMX? I haven't inspected the rig yet but will follow these instructions found here to repair it: /g/QRPLabs/topic/107789309#msg127369 I know that FT8 is 100% duty cycle and that can be hard on rigs but I'm wondering if I should just use my QMX for CW. I'd rather be operating than changing blown FETs. Thanks. Paul VA3ZC

I'm thinking of rewiring T501 to change from a 12V unit to a 9V unit. Can I use 20 gauge wire instead of the supplied 22 gauge? Paul VA3ZC

We had six folks join the MI QRP Zoom Chat on 10 April. Please join us Thursday April 17 (and every Thursday) at 4PM Eastern for the Michigan QRP Club weekly QRP Chat where the main topics will be QRP and other ham interests. New hams are encouraged to participate and ask questions. It's fun, it's easy, and it's free. You only need a computer, a smart phone, or a tablet that can connect to the Internet. OR if you can't be close to any of those you can join by audio with any standard phone. Just follow the directions below. No software needs be loaded or installed. Anyone can join and non members are welcome. Details are here: https://www.miqrp.net/zoom Zoom ID: 811 0835 6229 The topic for Thursday, 17 April will be TBD. Ed AB8DF Ernie NE3TE Tony W8CDC Stan WB8QJZ Casey KC9IH Stuart M0SGV Started out talking about cars. Ernie just got a new one. Ed showed this new paddles. https://www.ur5cdx.com/index.php?main_page=product_info&cPath=21&products_id=52 Northern Michigan ice storm caused major damage. It has been over a week and there are still major power outages. Stan played with satellites during the week but did not have any luck with the ISS and slow scan. Tony used to work the OSCAR 7 and 10 back in the day. Stan has a handheld that automatically tracks birds and the upcoming passes. DM1701 with open GD77 firmware is the way to go https://www.amazon.com/Baofeng-DM-1701-Channels-Programming-Earpiece/dp/B07R7QM63X?th=1 Stuart is still working on his Michigan Mighty Mite and wants to see how it looks with his new Tiny SA. Casey is playing with antennas and some hamsticks. Spending a lot of time on FM nets. We talked about the 80 meter nets and swap meets. The agenda for the 10 April QRP Chat: Ernie to do a short introduction and acknowledge any new folks to the Zoom chat. The topic for next week will be an open forum. During the open forum anyone can take the floor. We will go one by one until all have had a chance to have the floor. Files, pictures and presentations can be shared if you have any. Please try to stay muted when someone has the floor. Thanks Ed AB8DF

? ? I sent my QMX+ to? Jeff early in March feeling that it was beyond repair. He found a load of problems, mainly bad soldering. He felt that it could be redeemed and sent me comprehensive details of the defects and costs. He approached the project with a great deal of knowledge and enthusiasm for which I a very grateful. I would be very happy to recommend him. Kind regards and 73s to all, James Silvester MJ7HEE ?

Could the digi mode be switched off in the system configuration? juergen dl8zad

Hello OGs, YLs, Question, actually it could be a feature request.. The stm32 chip has an internal real time clock. Wouldn't it be nice to make usable? Currently the clock may be shown on the display ant it starts counting - starting from zero on power-on. Two things would be needed: - software - a settigs menu where the user would be able to set current time without a need of playing with gps - hardware... the diagram shows that cpu's vbat leg is connected right to the gnd... adding small battery there would be required to persist the time on power off. And since stm32's rtc draws some microAmps, some small button battery should suffice. What do you think?

Hi, My QMXs work great under Windows with wsjtx. I have wsjtx installed on the Raspberry Pi 4 and 5. There's no control. Only two dots appear under the A in the frequency display. But that's not enough for the QMX to transmit. What could be the cause, and what should I do? Vy73 Reinhard DL3AS