Re: A little toy for PCB rework
I wonder if these are torch tip cleaning tools?
Roy WA0YMH?
From MPJA, a tool to clean out solder-filled holes in PCBs.
<>
No financial interest in this company,?except to keep them in business.
73 Jim N6OTQ
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Re: #qmx Don¡¯t Use USB-C PD to power your QMX?!
#qmx
Hot Plugging is the killer too, it takes the human brain a few ms to get that connector in that socket first time and
with a steady hand.
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It's been 2 years since I was on FT8. Yesterday I looked up Hans's instructions for setting up the QMX on WSJT-X (Win10) and they were clear as could be and very simple. For some reason I got a couple of hamlib errors, but they mysteriously went away. I quickly logged 5 20m QSOs at 5w and 3 40m QSOs at 4w, through my multi-band EFHW antenna which is very close to resonant on those bands.?
I'm still 90% CW, but FT8 is a nice diversion.
Thanks, Hans!!
73, Randy, KS4L
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Re: A little toy for PCB rework
I don't agree with his wood burning monster on a PC board to
remove multiple pins.
There IS the problem of too much heat! Precision is called for.
....Dave
On 9/18/23 10:56 AM, Rich Brandt, AE8AA
wrote:
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Removing solder from holes in your boards EASILY.? (I post this
every time the question comes up.)
A while back, Keith AG5GW posted this topic
in which he linked
by
His description and demo on removing solder from holes:
Recommended.? All should review the video.?
The essence is, use solder braid to wick out your clogged
holes BUT DIP THE BRAID IN LIQUID FLUX BEFORE YOU START.?
There are more tips than that, and the demos are worth
seeing.? You don't need a desoldering vacuum system, or a hand
desoldering plunger pump, or a stainless steel needle.? Braid
and liquid flux and a little finesse --?
which this guy shows you -- gets it done.
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Re: QMX Build disaster No. 1
Hi Hans,
I finally finished the build without any further issues. It all works as expected. Very pleased with it.
Many thanks for creating these kits.
Martin
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Re: More on spike and avalanche breakdown
On Sun, Sep 17, 2023 at 10:39 PM, Tony Scaminaci wrote:
How this would be done at HF frequencies is beyond me. The trombone line length would be so large we¡¯d have to climb a ladder to pull it all the way around the Smith chart lol.
Short and open are easiest to define and produce and one or the other is often the worst case. For those other cases we used to use a high-Q tuned circuit (air variable cap, air-core inductor), which would cover much of the Smith Chart when tuned through resonance.? A strategically-chosen added length of transmission would allow coverage of the rest.? Of course you need a different circuit per test frequency. This was at VHF and UHF, mostly, though HF parts would be load-pull tested at 30MHz.? IIRC, we ran 12V parts at 16V and overdrove the part by 3dB beyond saturation so it was a severe test.? I also think that the QRP Labs class D and E amplifiers are less troubled by stability issues than class? A and AB. 73, Don N2VGU
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Re: Circuit board and mounting hole dimensions.
#clock
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Back in the dawn of time we had a WWVB receiver that we checked our lab standard with, and WWVB was only stable overnight in MA. ?I'd have to say if you can get a good (ground wave) signal 24x7 you might be able to lock a local standard to it, but otherwise you might have to watch the reference and tweak your standard occasionally, as we did.
I'd use a GPSDO, those are easy, cheap, and usually pretty solid.
73, Willie N1JBJ
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On Sep 17, 2023, at 5:27 PM, Jerry Moyer via groups.io <ac5jm@...> wrote:
There are several cheap WWVB receivers available.? Has anyone successfully implemented WWVB as a 1pps time source rather than GPS for QRP Labs kits?? How did you do it and what are the pros and cons between WWVB and GPS?? One that comes to my mind is a clear view of the sky is not required with the WWVB 60kHz signal.? A disadvantage might be potential interference to 60kHz from LED light dimmers and such.? Which is more reliable?? Maybe have one automatically back up the other?
-Jerry AC5JM
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A big problem with VLF time standards is their keying is accurate to around 1mS.? It depends on things like the tuning and matching components and antenna used at the transmitter.? I believe that the 60kHz transmitter here in UK (MSF) uses a "crowbar" across the antenna to rapidly quench the transmitted signal to ensure that the keyed waveform drops within 1mS of the second epoch.? If you were to use such a signal for synchronizing a standard oscillator, you would need to average the keying pulses over a considerable time period.? Then you might run into the diurnal variation in VLF signal propagation as the ionosphere changes between day and night.? Compare with a GNSS receiver which typically has a jitter in the 1 second pulse of 10 to 20nS and a much more stable propagation path.
--
Peter Lee
G3SPL
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Re: A little toy for PCB rework
Removing solder from holes in your boards EASILY.? (I post this every time the question comes up.)
A while back, Keith AG5GW posted this topicin which he linked by His description and demo on removing solder from holes: Recommended.? All should review the video.? The essence is, use solder braid to wick out your clogged holes BUT DIP THE BRAID IN LIQUID FLUX BEFORE YOU START.? There are more tips than that, and the demos are worth seeing.? You don't need a desoldering vacuum system, or a hand desoldering plunger pump, or a stainless steel needle.? Braid and liquid flux and a little finesse --? which this guy shows you -- gets it done.
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Re: More on spike and avalanche breakdown
The fact that open and short are only two possible states misses real loads.
That the load can if reactive cause a shift in the operating point of the BS170s.
The way to set other states is fairly simple, a good old 365p capactitor
across the load.
I have posted about this before, and it fell into the bit bucket.
--
Allison
------------------
Post online only,?
direct email will go to a bit bucket.
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Re: A little toy for PCB rework
If you can find a hat pin you don¡¯t need a pin vise.
Phil K3UT
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Re: Newbee Q: Are there 'designated builders' for QRPLabs kits?
Mark, I live in West Allis and have built 2 QDX kits. They both work great. One for myself and oner for another ham. If you are interested, I'd be happy to help you out as we live very close. I also love building kits. I'm also retired so I have the time. :)
73,
Dean - KC9REN
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On Sun, Sep 17, 2023 at 10:25 AM, Mark/KD9NOO/airchecklover wrote:
I see the QRPLabs wait list is over 6 mos. long.?
Is there such a thing as a "designated builder" list?
Thanks,
Mark? KD9NOO
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I live about 600 miles away from WWVB also (in Idaho). My wristwatch WWVB receiver also only tries at night. If I force it to try during the day, it is hit or miss. I can only assume that my wristwatch radio has marginal sensitivity, at best, for good 60kHz reception. Well, it¡¯s a radio stuffed into a tiny wristwatch package, so that¡¯s not surprising. :) I also have a wall clock that receives WWVB but I don¡¯t know when it tries to sync and the seconds are always right on (I¡¯ve never had to mess with it).
A company called Canaduino still sells a WWVB receiver module. You can find them on Amazon for about $13 or so. Or, some people have luck harvesting the module out of cheap used clocks if you know what to look for.
You would have to hook up the Canaduino module to a Arduino or similar to try and decode the WWVB signal into a 1 PPS. I don¡¯t think you¡¯ll get it directly from the module. And I¡¯m not so sure it would be accurate enough to use for calibration (like a GOS 1 PPS pulse) but maybe?
73, Gregg
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Re: QMX LPF for [80m/60m] - Version 1 measured results
I remeasured the insertion loss with the LPF switching diodes operating with default transmit bias current. It's noticeably reduced. See attached sweeps. Worst-case loss on 60m now about 0.9dB for the LPF and both diode switches. 80m is about 0.6dB. I'd be interested to know if anyone has figures to compare with any of the original filters.
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I live in the Philly area. I can only hear it sporadically?at night. Indeed, I have a few wrist watches with WWV RX's in them . They try to sync at 1,2,3 & 4AM. This night time reception appears to be a "thing". I have many clocks that only try at night.
Maybe 600 miles is close enough for the groundwave??
Used to be that you could buy a tuned/resonant WWVB antenna from a guy in CT via ebay. He's got a few Youtubes about tuned antennas. In his video's?he's always able to receive WWVB on 60KHz with one of his antennas.
Mark/NI2O
Really?? I didn't know that.? I have always been able to hear the 60 kHz signal 24/7 in northeast Oklahoma 600 miles away.? I thought WWVB was designed to cover at least the lower 48 states of US the same.? The only situation that I have experienced when it cannot be heard is when there is local interference covering it up.? I have literally never not heard it when I tuned it in with a decent receiver with almost any length of wire for an antenna.? Maybe 600 miles is close enough that it works all the time??
-Jerry AC5JM
On Monday, September 18, 2023 at 05:34:09 AM CDT, Daniel Walter via <nm3a= [email protected]> wrote:
Have not tried this and don't know if it's even possible. But even if it is, in most areas of NA, it's only receivable at night for a few hours.?
--
73, Dan? NM3A
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Really?? I didn't know that.? I have always been able to hear the 60 kHz signal 24/7 in northeast Oklahoma 600 miles away.? I thought WWVB was designed to cover at least the lower 48 states of US the same.? The only situation that I have experienced when it cannot be heard is when there is local interference covering it up.? I have literally never not heard it when I tuned it in with a decent receiver with almost any length of wire for an antenna.? Maybe 600 miles is close enough that it works all the time??
-Jerry AC5JM
On Monday, September 18, 2023 at 05:34:09 AM CDT, Daniel Walter via groups.io <nm3a@...> wrote:
Have not tried this and don't know if it's even possible. But even if it is, in most areas of NA, it's only receivable at night for a few hours.?
--
73, Dan? NM3A
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Additionally, the rotary encoder fails on the terminal hardware test.? I ordered this replacement from Mouser,?? The picture is wrong but the specs appear to be a good replacement for my defective encoder.
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Re: A little toy for PCB rework
But melting the solder and then wacking the board on the table is so much more fulfilling. ?
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Re: Finally a somewhat successful QMX build
#qmx
2 - You can not power down the radio when using the terminal.? It seems all the controls are disabled when using the terminal program.
You can, but not while the terminal program has an application open or has entered the configuration. So the terminal program would need to be just at the main menu.?
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Randy
Donald S Brant Jr
Mark Phillips