Very interesting.
The author appears to be affiliated with Oregon State University (not far from my QTH).
The "source code" file appears to contain only documents, not actual source code.
So a certain amount of trust will be involved when installing the APK.
73, Mike KK7ER
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The beatings will continue until morale improves! -- Ryan Flowers - W7RLF
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Re: qcx+ 200Hz filter gain
Hi Mike. Since the problem corrects itself when applying 12v to pin 7 of IC7 and doesn't stay fixed, you may have a capacitor issue. C9 (47 nF) connects from pin 5 of IC7 to ground. It may be leaky. With the power off, check resistance from pin 5 of IC7 to ground. It should be a couple megohms after that capacitor charges up.
73 .. .Ron
Any suggestion please.
The QCX+ 200Hz filter has no gain. All the DC voltages and Waveforms are okay up to and including IC7 but the DC voltages on IC8 bias pins are not 2.5v ish but only 0.8v. I accidentally shorted pins 8 to pin 7 on IC7b and everything started working normally including all the voltages on IC's 8, 9 and 10. When I powered off again the fault was back but if I again shorted pin 8 to 7 on IC 7b all works normally. All values of components checked plus? around these areas. Any ideas why putting 12V to pin 7 of IC7? makes everything work normally? I don't like changing components unless I have to but have changed IC8.
Any help gratefully received.?
Thanks?
Mike G4TSQ
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Re: Earthquakes in Turkey
Saw the news, came here to see this. I'm glad my favorite QRP Hall-of-Famer and his family are okay! Having experienced severe quakes in Southern CA as a youngster, (Loma Prieta, Landers etc) I know how rattling they can be even when you're not on top of the epicenter. 73 to all.? -- Ryan Flowers - W7RLF
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Any suggestion please.
The QCX+ 200Hz filter has no gain. All the DC voltages and Waveforms are okay up to and including IC7 but the DC voltages on IC8 bias pins are not 2.5v ish but only 0.8v. I accidentally shorted pins 8 to pin 7 on IC7b and everything started working normally including all the voltages on IC's 8, 9 and 10. When I powered off again the fault was back but if I again shorted pin 8 to 7 on IC 7b all works normally. All values of components checked plus? around these areas. Any ideas why putting 12V to pin 7 of IC7? makes everything work normally? I don't like changing components unless I have to but have changed IC8.
Any help gratefully received.?
Thanks?
Mike G4TSQ
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Re: Earthquakes in Turkey
Just woke up and saw the news. It's pretty bad over there. Not only was the magnitude high but it was shallow at around 11 miles down. Unfortunately, the number of persons injured/killed is only going to go up in orders of magnitude. I have friends there but haven't heard anything from them yet. I imagine comms are affected with the exception of amateur radio.
--
Wayne S.
KF7RCM
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Re: Earthquakes in Turkey
Hans hope you, family and friends are ok. Also prayers offered for all of Turkey
Everett Catlin WA2BHS
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Re: Earthquakes in Turkey
Hans,
Very thankful you and your family are safe. ?For those of us who pray we will be doing so for all those affected by this tragedy. 750 km away doesn¡¯t seem like that far away considering the severity of the quake. Praying that your QTH is safe.?
I, and I¡¯m sure others, would like to contribute to relief efforts for Turkey as they begin. I¡¯m always hesitant to contribute based on news articles alone. However, if at some time in the future, you can endorse a group that is helping I would be happy to contribute.?
Stay safe and God bless.?
toggle quoted message
Show quoted text
On Feb 6, 2023, at 08:37, Hans Summers <hans.summers@...> wrote:
? Thank you Hugh, Tony and all
Terrible times indeed. We are all fine here thank you, my QTH is about 750km or so West of the affected area. The devastation on the news channels is severe.
Yes indeed. A horrible tragedy. It affects Syria also.
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Hi JP
Ooooohhh I forgot that. I must take care of that duty now. I was so happy to see a whole box of 210 beautiful QDX boards in 35 panels of 6, each individually wrapped, that I forgot!
On Mon, Feb 6, 2023 at 5:01 PM JP McGinley < j.p.mcg@...> wrote: Hans,
? Hopefully your?genius?colleagues were flogged to within an inch of their lives.? How dare they stop you
from taking our money!!!
JP
KA3BWP
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Hans,
? Hopefully your?genius?colleagues were flogged to within an inch of their lives. ?How dare they stop you
from taking our money!!!
JP
KA3BWP
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Ian, assuming you have the frequency display set to 7,020,00(0), use the formula:
x = (7020000 X 27004000) / measured freq in Hz
"x" will then be the required reference frequency in Hz.
73 .. .Ron
On 06/02/2023 08:40, G0VGS via wrote:
>It does
> appear, however, to be slightly off frequency.? The reference frequency
> is set to default (27.004).
Ian
Yes, section 8.5 in the manual gives the clue.
It can be done by careful calculation or "try it and see".
73 Alan G4ZFQ
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Hi all
Whilst I have 1,000 more QDX Rev 5 PCBs in manufacturing... today on my return from 2 weeks away, I asked my colleagues to do a complete stock take of everything to see what else I'm low on stock. During that process... my dear genius?colleagues discovered a previously neglected box in their stock cupboard containing 210 more QDX Rev 5 boards! So we are NOT out of stock as I had thought last week...?
Therefore?I have removed the "pre-order terms sometime in February" thing from the QDX shop page. And we will now ship the pending orders that were supposedly waiting for "sometime in February". And in fact since we actually ARE in February, not all is lost...?
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If it was transmitting for any length of time with no antenna or dummy load attached, then the three output BS-170 MOSFETs are most likely blown. It is also possible that Q6 and IC3 are bad as well. Start by carefully removing one of the BS-170s and testing it. Be careful to not damage the board while doing this. If you don't have some kind of solder removal tool, try solder wick and liquid flux for this operation. If one BS-170 is bad, then all three are likely bad. While you have all three out of the circuit, look for the drive signal at the gates of the MOSFETs. It comes from IC3 and should measure about 2.5 volts DC on your DVM. If that isn't there, then IC3 is bad. If it is there then look for 12 volts on the collector of Q6 while transmitting. If that isn't there or is there whether keying or not, then Q6 needs to be replaced. Note that the 12 volts should come up rapidly when keyed and diminish slowly when unkeyed, in the absence of a load. If all that is now well, install new MOSFETs and test the transmitter into the dummy load.?
Good luck .... Ron
Yesterday I managed to find that I had a short that caused it to always be trying to transmit. I have fixed that and I have successfully completed the alignment procedure.
As far as I can tell the radio is now fully functional with the exception that measuring the output using a QRPLabs dummy load, the output voltage is 3mV during receive and drops to 1mV when transmitting. I assume I have blown something in my PA due to continuously being transmitting (although throughout my testing thus far, I have been measuring the current draw and it hasn't gone above 200mA).
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Re: Earthquakes in Turkey
Saw the news as well. Terrible for those impacted.??
Glad to hear your well Hans.
--
Allison
------------------
Post online only, please no email.
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Re: Earthquakes in Turkey
Thank you Hugh, Tony and all
Terrible times indeed. We are all fine here thank you, my QTH is about 750km or so West of the affected area. The devastation on the news channels is severe.
Yes indeed. A horrible tragedy. It affects Syria also.
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Re: Earthquakes in Turkey
Yes indeed. A horrible tragedy. It affects Syria also.
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Re: BPF Peak Issue / Question
Nice job Levi. Glad you found it.?
73¡¸é´Ç²Ô
On Sun, Feb 5, 2023 at 23:20 Levi ¨C K6LCM < lcm@...> wrote: Thank you, Ron. I checked all of those voltages and saw that 5, 6 and 8 were measuring 0.9 v. All of the wires on the T50-2 toroid had continuity but one or more must have had some amount of excessive resistance from incomplete enamel removal. I reheated these toroid wires once again and the voltages popped up to 2.5v and the BPF amplitude scaling factor jumped up to 08-09.
I think I am all set. Thank you!
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Thinking of Hans, his family, and his friends and colleagues as I read about the destruction in Turkey. I know everyone on this forum hopes you are safe and wishes you well.
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On 06/02/2023 11:26, Richard wrote: I haven't seen any info about the 4-capacitor short Richard, One of the many past posts referring to this is /g/QRPLabs/topic/96637601#98443Reading/searching old posts will reveal a lot more. It seems many do not have need to remove them, but do anyway. Also presumably to get it to transmit while running the input analysis is to use the PTT socket I do not think it is intended to TX, just to observe the input. Maybe interesting but not essential! I think the manual gives details of the setup if you really want to. 73 Alan G4ZFQ
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Yesterday I managed to find that I had a short that caused it to always be trying to transmit. I have fixed that and I have successfully completed the alignment procedure.
As far as I can tell the radio is now fully functional with the exception that measuring the output using a QRPLabs dummy load, the output voltage is 3mV during receive and drops to 1mV when transmitting. I assume I have blown something in my PA due to continuously being transmitting (although throughout my testing thus far, I have been measuring the current draw and it hasn't gone above 200mA).
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Ronald Taylor
JP McGinley KA3BWP
Hugh Mason 9V1SA / G4MRE / AI7QX