Re: QMX - smoke - another C107/Q108 failure
It looks like about 38 seconds or so, if I'm measuring this right.
Jonathan KN6LFB
By
Jonathan Burchmore
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#108744
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Re: QMX - smoke - another C107/Q108 failure
Here's a tighter view:
And zoomed in on the linear regulator portion. ?Vertical scale in both is 500mV/division with a -1.5V offset.
Here's a similar trace with channel two showing LIN_REG_EN.
By
Jonathan Burchmore
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#108743
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Re: QMX substitute for Q103
I don't see why it should not work with the AOD21357. Specs are very similar to the AOD403 and both are well over dimensioned for this purpose. I would try it if I were in your shoes.
Experience is
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aa0jr Jakob <aa0jr@...>
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#108741
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Re: #QMX holy smoke released again, C107 and D108 destroyed
#qmx
IF IT FITS and you want to use a premium cap, I would use the Kyocera TPSE477K010R0050 for $2.58 at Digikey, qty 1. It is 470uF 10% tolerance 50 milliohm ESR, Not cheap, but this series is surge
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Steven Dick, K1RF
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#108740
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Re: BS170 Fail
Or put an absorptive bridge between the QxX and switch it in for tuning, then out to operate. Also don't let the tuner auto tune when it detects a change in SWR.
--
73, Dan? NM3A
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Daniel Walter
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#108739
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Re: QMX - smoke - another C107/Q108 failure
The 1N4148 diode in series with the linear 3.3V output is a necessary evil
to prevent backward current flow once the 3.3V SMPS rail comes up. However,
it destabilizes the linear 3.3V rail as noted by
By
Tony Scaminaci
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#108738
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WSJT-X results
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73
Karl
KI4ZUQ
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Karl
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#108737
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Re: QRP antenna tuner?
Looks good Karl, does it work good for you? I have one sitting in a box in Florida waiting for my return to assemble it.
4S has some good kits and they have a great organization too.
I activated my
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KK4ITX John
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#108735
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Re: QMX - smoke - another C107/Q108 failure
Jonathan,
After turning the power OFF and having the 3.3V VDD drop to 0V, how long does the 5V VCC stay at xxV ?
73 Kees K5BCQ
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Kees T
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#108734
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Re: QMX - smoke - another C107/Q108 failure
Hello Hans and Jonathan,
The plots require some questions to be answered in my mind.
1) What is happening to 3.3V between t=80ms and t=200ms after Power ON ? Need more detail on the actual voltage
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Kees T
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#108733
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CAT port returns ` ` ` on QCXmini
Just curious if anyone has seen this and might know what's going on.? Using Putty on the CAT port of a QCX-Mini, the QCX returns a (`) with each character typed.? ?For example, if I type FA; and
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Jerry Moyer
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#108732
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Re: QDX rev 5 Troubleshooting
First, it is considered good form always to post your name and call at the end of a post.? Then, others can direct their posts to the correct person.? Also, when posting in response, direct the post
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Evan Hand
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#108731
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Re: BS170 Fail
Wayne,
Thanks for the reply!
Read over other posts here about use of auto-tuners and the Q-Line. In some cases they'll show a momentary high VSWR to your rig. The PA in QCX-QDX-QMX doesn't like too
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Al Holt
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#108730
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Re: QRP antenna tuner?
Picture of a 4sqrp tuner...
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73
Karl
KI4ZUQ
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Karl
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#108729
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Re: QMX working FB then shorted out. Ideas?
Steven,
Thanks so much for the response. I'll get to it and respond when I know more. I've a lot to learn here.
73,
Cliff, AE5ZA
By
Cliff
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#108728
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Re: QDX rev 5 Troubleshooting
Thanks again John and Nick,
Managed to get some more PD time.
I disconnected the cat on D3 and D6 to see if that told me anything but I don’t think it it did, results below, look like the only
By
laycockc+GIO@...
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#108727
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Re: A weird problem
A QDX which w1NC did over for me. Thanks. I will be back later this afternoon.
HIF
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Leland Lannoye, W9HIF
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#108726
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Re: BS170 Fail
Hey, Al, but I will admit, it's not one specific for QRP. It's my shack's auto tuner. That might not be the best choice.
Wayne
By
Wayne KB4DSF
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#108725
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Re: BS170 Fail
Hey, Roger. I've not noticed any SWR fluctuations, but you bring up a good point. I might have to watch that more closely when I repair the radio.
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Wayne KB4DSF
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#108724
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Re: BS170 Fail
Wayne,
Are you using any kind of antenna tuner?
I think using a manual tuner with a switchable SWR indicator is a good way to prevent future BS170 failures.
Good luck with the repairs!
--Al
By
Al Holt
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#108723
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