I need some help with my QCX20 ver. 3.? It originally worked, receiving well but only 1.75 watts output.? I measured 5.1 watts at the drain on all BS170’s? I then reworked L1, L2 and L3 removing a couple of turns from each.? It seemed to make little difference in the output but then I smelled heat and smoke and shut it down immediately.??Capacitor C26 appears to have gotten very hot.??I have not replaced it yet. Now I have no LCD except the two rows of squares, no receive or output.

I have 13.36 and 5.0 out from the regulator.

I have .01 on both Clk0 and Clk1.

C2 is 3.42; D2 is 5.02; T1 pins 1,2,3,4 are 0 and pins 5, 6.7, 8 are 2.47.

Top of C43 is 2.47; C44 is 1.28; C45 is 1.28; C46 is 2.47.

LCD PIN 1 – 0.00?????????????? (0.00)

LCD PIN 2 – 4.98?????????????? (4.94)

LCD PIN 3 – 1.58 ????????????? (0.57)

LCD PIN 4 – 0.00?????????????? (4.92)

LCD PIN 5 – 0.00?????????????? (0.00)

LCD PIN 6 - .20????????????????? (0.00)

LCD PIN 7 – 4.97?????????????? (1.08)

LCD PIN 8 – 4.96?????????????? (1.08)

LCD PIN 9 – 4.96?????????????? (1.06)

LCD PIN 10 – 4.96???????????? (1.04)

LCD PIN 11 – 4.48???????????? (0.00)

LCD PIN 12 – 4.36???????????? (4.94)

LCD PIN 13 – 4.12???????????? (4.92)

LCD PIN 14 – 4.12???????????? (0.00)

LCD PIN 15 – 4.66???????????? )4.41)

LCD PIN 16 – 0.00???????????? (0.00)

?Thanks for any help.

Gary K4VIG

I am able to test with qcx.?

Does anyone have or is anyone able to help me write a simple arduino sketch to turn on the QRP Labs Si5351A Synthesiser Module, PCB Rev 4?

I just want to turn on clk0 for a period so I can test whether the unit is working.? Also, I'd like to see my small scope work.? I know it works on low frequencies with the qcx as a signal generator.??

Any help would be appreciated.??

Very nice indeed!

开云体育

Hear hear! These guys are the best of the best. One of the big ingredients in being that good is the ability to copy CW by ear in adverse conditions far better than any machine or software can. They may be using a computer to send CW but none of them would ever use a CW decoder. No decoder would be anywhere near as good at copying signals in QRM or weak signals as a good CW contester's ears and brain. To use one would immediately remove any chance of winning or placing well in a contest.

Paul N1BUG

Hay there James
Yes the U3s works fine up to the start of transmitting then reboots
Yes I can go through all the menus and set the correct info
Yes different power supply same results
Home made PSU running to 7805 5 volt regulator.
I have been into building and repairing radios for almost 55 years. I am 70 years old and got my first ham ticket in 1975.? I have built about 30 Heathkits including the complete SB-104A station.. Repaired Kenwood TS 820s, Icom 740 Many kits built by others. Lots of AA5 type radios etc. etc. So I can solder. This U3s was working well but the Atmal 328P became corrupt and factory reset did not solve the problem. That is why I am trying to flash the firmware.
Now my error reads,,,,
Reading | ################################################## | 100% 0.00s
avrdude.exe: Device signature = 0xffffff
avrdude.exe: Yikes!? Invalid device signature.
???????????? Double check connections and try again, or use -F to override
???????????? this check.
avrdude.exe done.? Thank you.

I don't understand where to use "-F" so I can't try that yet.
My wire connections are correct and the same as the arduino sketch list them. I know the 328P is corrupt because I tried a new chip from QRP labs. I have ordered a new chip but won't get it for a couple weeks. Any Ideas? Carl?? AB1ZI

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No sorry, these guys KNOW CW, and can copy it better than ANY computer program.? Especially in conditions with QRM.
PERIOD!

Joe WB9SBD

I had a look at the WRTC2018 competition and tried to work some of the HQ. Got 25 of them despite the pile ups. There was a video about the competition site showing the operation in a tent of one team. CW on the computer only.? And I was wondering about hte incredible speeds they operated with. Thanks to the CW decoder on the QCX which seems to work best with high speed.? What for using CW, when in the competition I am against computers with operators probably not even knowing CW.
Fake CW I would say.

The first U3 I built years ago I seem to remember having a similar problem. I was using a very small phone charger I seem to remember which caused all sorts of problems.

Swapped it out with a linear PSU and never looked back.

Cheers. James.

Before you flash the U3 did you check what Roger suggested.

Is the U3 working fine before transmitting?
Can you go through the menus etc..
Have you tried a different PSU.
What PSU are you using first.
Is it your first build of this kit kit.

Cheers James.

Dam it James, I think you hit it on the head. No I didn't flash the arduino. What a Dumass I am.I will do the arduino? and try it again. Some one smack me up side the head. I'll let you know. Carl

开云体育

That's a good call Roger.

Hello Carl.

Have you tried a reboot of your PC after installing the libusb.dll.

Also, are you selecting the arduino from the Avrdudess drop down menu.
I'm assuming that you have flashed the arduino isp sketch to the arduino.?
And are you selecting the correct com port to be used with the arduino as the programmer.
Can you see the arduino com port in your PC device manager.

I've always found zadig a useful tool to install peripherals like the arduino etc to the PC to be used with Avrdudess too.

Kind regards, James.

Are you sure that your power supply is sufficiently robust? I had a similar problem with my u3s; changing the power supply fixed the problem. You might try putting a 4700uF cap across the power and see if it helps.

Roger
G3YTN


--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

I am looking for help installing firmware on my U3s. I am using Arduino IDE as the ISP. Also using Avrdudess. I had a hard time getting the libusb0.dll installed but now have it in the two windows folders per instructions, I now don't get an error starting Avrdudess any more, However, I do get this error massage from Avrdudess,,?

avrdude.exe: stk500_getsync() attempt 10 of 10: not in sync: resp=0x00
avrdude.exe done.? Thank you.

Now I am lost. Can anyone help me with this problem?? The U3s reboots every time it starts to transmit. I tried? a restore with the same results. Carl

Steve,

Changing QCX CW OFFSET has no effect on the filter center frequency or bandwidth.


Brady,

Assuming you bypassed the onboard filter (discussed above) there is no reason QRP Guys filter will not work unless their input impedance is so much lower than QCX PHONES jack is designed to drive.

72, 73
John
N3AAZ