Right now, I'm using the venerable 7805 linear regulator with a small heatsink to power my QLG1 and Clock.? Together they draw about 100ma.? Doing this allows me to connect up to any 6 to 15 VDC power source I have.? I consider the regulator defense against transients and other poorly regulated wall warts that would destroy both gizmos.
Now, I'm considering using one of , which is much more efficient than the 7805, i.e., no need for a heatsink.? Not really all that cheap but I'm using one in another application and I've not had any problems.? I will handle 1.5A load at 90+% efficiency.
73 Cliff k1iff
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Hi and HNY to all.
Sadly I'm going to be a grumpy old S*d.
Unlike many lucky people, I have an internet connection that speeds along at
less than 250kbs, as do many other members who don't live in centers of
"broadband excellence". A video attached to an email today has jammed my
system for most of today, with dropped connection, timed out etc. it was a
25Meg file that I did'nt want, but had to download because it was there.
If people want to jam my system, then fine. I'll spam them to the dark ages
(ok, I'm Trumping). Please don't send huge attachments. It buggers a lot of
peoples email communications.
very happy new year to all, 73 Mike G8NXD ( whose broadband is slower than
dial-up)
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Yes, I have had that problem, especially with the older phone chargers. But many of the newer ones, are fine. I usually give them a light load and watch the output for a while.? I have had times when I returned from the dump with 20+ in a bag, checked them, and threw 15 back. But the price is right!? ?The same source works for displays if you play with Arduino stuff. The Nokia phones come apart easily and the display is the same on sold by many of the vendors.? ?I don't pick the dump like I used to, but some things are just too convenient and cheap ! Also small motors and switch
On Mon, Jan 1, 2018 at 10:48 AM, Roger Hill <rhill@...> wrote:
Hi Frank.
That's what I did to start with...I took an old 5 volt phone charger and used it. But then I was having drift problems with the U3S? - it was gradually increasing frequency with use, ending up about 100Hz high from the dial frequency -? and finally discovered that my '5 volt' charger was producing 6.68 volts ...very stable, but very high!
Changing that out for the one I mentioned earlier, which was very steady at 5.01 volts by my meter, fixed my drift problem.
Roger
G3YTN
On 2018-01-01 15:33, Frank W1FRA wrote:
For years, I have gone to the local Transfer Station, ie the Dump, and simply collected cell phone chargers, all 5VDC, and especially the newer Motorola ones, very stable. Free, get to know the people working there, and they will even save them for you. And free.
?
I especially like the ones that are used with Fisjer Price toys. They are rugged, and very stable.
?
Frank? ?W1FRA
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Hi Frank.
That's what I did to start with...I took an old 5 volt phone charger and used it. But then I was having drift problems with the U3S? - it was gradually increasing frequency with use, ending up about 100Hz high from the dial frequency -? and finally discovered that my '5 volt' charger was producing 6.68 volts ...very stable, but very high!
Changing that out for the one I mentioned earlier, which was very steady at 5.01 volts by my meter, fixed my drift problem.
Roger
G3YTN
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On 2018-01-01 15:33, Frank W1FRA wrote:
For years, I have gone to the local Transfer Station, ie the Dump, and simply collected cell phone chargers, all 5VDC, and especially the newer Motorola ones, very stable. Free, get to know the people working there, and they will even save them for you. And free.
?
I especially like the ones that are used with Fisjer Price toys. They are rugged, and very stable.
?
Frank? ?W1FRA
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For years, I have gone to the local Transfer Station, ie the Dump, and simply collected cell phone chargers, all 5VDC, and especially the newer Motorola ones, very stable. Free, get to know the people working there, and they will even save them for you. And free.
I especially like the ones that are used with Fisjer Price toys. They are rugged, and very stable.
Frank? ?W1FRA
On Mon, Jan 1, 2018 at 10:25 AM, Roger Hill <rhill@...> wrote:
Hi Vince
I used this Raspberry Pi psu from Amazon.
I cut the micro usb plug off the end, and also used a 4700uF capacitor across the power terminals inside the U3S case. It worked fine.
I have since replaced it with a home brew LM317 regulator arrangement, so I now feed the U3S with 12volts from my 'used for everything' power supply, and regulated it to 5 volts. That also works well, even though the LM317 gets quite hot.
What that also does is let me use the 12V supply to feed the BS170's, but I have not done that yet.
Roger
G3YTN
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**
Roger Hill
**
On 2018-01-01 14:46, V Zecchinelli wrote:
Can anyone suggest a reliable/stable 5dc P/S for U3S?
73 N1VIN? Vince
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HF beacons for US launched balloons
One of the great aspects of the Amateur Radio hobby is the wide variety of activities and sub-topics. One can move in and out of different areas of the field- wherever your interests take you. Having only been a licensed amateur for a bit over 30 years, I still learn something new regularly.
Of interest to me, is the recent proliferation of high altitude balloons with sensors and telemetry transmitters aboard. For many years, these beacon transmitters have been primarily in the VHF/UHF range. My understanding is that this was for a number of reasons, including the need for light payloads, and international regulations concerning unattended (un-controlled) beacons. Of late, I see many that are transmitting in the HF spectrum, using the weak signal modes of WSPR and JT9, for example.
It has always been my understanding of FCC regulations that unattended beacons below 28 MHz were not allowed for USA amateurs. This appears to have somewhat been ignored by the masses of people running WSPR beacons 24/7- These are not intended to be unattended transmitters. However...
I am curious if there has been an exception made for balloon flights for these unattended HF beacons that are operating under FCC regulations and carrying US callsigns. If this is the case, I would greatly appreciate someone being able to help me locate the appropriate regulation or notice from the FCC that allows this.
Thanks in advance,
Bruce Beford, N1RX
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Hi Vince
I used this Raspberry Pi psu from Amazon.
I cut the micro usb plug off the end, and also used a 4700uF capacitor across the power terminals inside the U3S case. It worked fine.
I have since replaced it with a home brew LM317 regulator arrangement, so I now feed the U3S with 12volts from my 'used for everything' power supply, and regulated it to 5 volts. That also works well, even though the LM317 gets quite hot.
What that also does is let me use the 12V supply to feed the BS170's, but I have not done that yet.
Roger
G3YTN
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**
Roger Hill
**
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On 2018-01-01 14:46, V Zecchinelli wrote: Can anyone suggest a reliable/stable 5dc P/S for U3S?
73 N1VIN? Vince
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Re: U3S20 balloon launched.
#case
U3S20 is trying to grab solar energy...I think it runs the first WSPR TX and stops.Second TX made it to JT9 but see calibration is off by 100hz high on the waterfall.Altitude is good...no WSPR data yet.
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1518?-26?-1.1?1749?@?CQ?N2NXZ?FN13
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1519?-26?-1.0?1749?@?4332.9?35.34
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Can anyone suggest a reliable/stable 5dc P/S for U3S?
73 N1VIN? Vince
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U3S20 balloon launched.
#case
Happy New Year to all.
This morning was an opportunity to launch U3S20 balloon.
Weather here in NY has been terrible and today was the best shot I had in weeks so took it.
Early launch and now have to see if it will power up in the sun once it rises more.Not sure what to expect using a new GPS.
30m WSPR x 2 / 30m JT9 x 2 (WSPR dial)
20m WSPR x 2 / 20m JT9 x 2 (14.078 dial)
Jim,N2NXZ
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Re: Loud tone on QCX 40
#qcx
It could be side tone getting turned on. Plug it into an antenna and see if there is any
On Mon, Jan 1, 2018 at 2:19 AM, KE0IMD <ke0imd@...> wrote: I am also experiencing a loud tone on my QCX 40. The tone resembles feedback and has a "hollow" sound to it. When I turn the volume up/down, the volume of the tone increases/decreases relatively. I've not plugged in an antenna, this is on startup and onward, which makes it unable to be calibrated.
I inspected my solder joints and everything appears fine. I followed the installation manual exact for the 40 meter kit. Not sure where to start on this one, I'm not an electronics expert like many of you here.
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Hi all I¡¯ve attached a short video of my 40m qcx up and running, I¡¯ve built several kits and I must say this one was a nice one, but I think when I order a 20m version I think it might be best to wind and install T1 first before the rest of the board is populated, I found it tricky! Thanks Hans 73 fer nw John M0CDL?
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Re: Loud tone on QCX 40
#qcx
I am also experiencing a loud tone on my QCX 40. The tone resembles feedback and has a "hollow" sound to it. When I turn the volume up/down, the volume of the tone increases/decreases relatively. I've not plugged in an antenna, this is on startup and onward, which makes it unable to be calibrated.
I inspected my solder joints and everything appears fine. I followed the installation manual exact for the 40 meter kit. Not sure where to start on this one, I'm not an electronics expert like many of you here.
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Re: Turn on your QRSS Transmitters!
This is no practical joke, we¡¯ve been doing the New Year QRSS Party for years.
There was an outage at ?yesterday which is where a lot of people host their grabbers.
73 Keith G6NHU
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On 31 Dec 2017, at 20:44, TrueBlue < 44-40@...> wrote:
Apparently, this is an elaborate practical joke:? As of 2043Z 31DEC2017 all the grabbers accessible from the western US are DOWN, including David's.
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IV output unable to drive FET driver hard enough?
Chris Wilson 01 January 2018
I use my U3S QRP Labs exciter to drive a PA on 137kHz, and it works
fine. Hans made changes allowing a 180 degree out of phase pair of
signals to come from the Si5351A synthesizer chip with the intention
of this being able to drive a push pull Class D FET driver chip
directly without a X2 signal being divided and split by a preceding
IC, please see original and simplified circuits below. I tried this
but the circa 2.2V outputs of the Si5351A chip is not sufficient to
drive the inputs of the IR2110 FET driver.
Any ideas please? Thanks and a very happy and healthy New Year to all!
Original PA circuit (works fine with "normal" U3S):
Modded amp circuit (simplified in the hope of building with one less
IC):
IR2110FET driver specs:
74F74 IC specs:
--
2E0ILY
Best regards,
Chris mailto:chris@...
--
Best regards, Chris Wilson (2E0ILY)
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Re: outboard cw decoder for the QCX
Hi I was wondering about the 4 row display my self as I have several doing nothing and would be nice to have one full line for can decide. It may allow another line to display additional information if the system can handle it. This only a suggestion and a nice idea if it doesn't impact on your time. I am still waiting for my kit it's killing me waiting but that is life.?
Barry?
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inventoried my QCX 30 and noticed there was no 33nF (C15) in th kit. Thought I would notify someone in case it is a kitting issue. Kit has 25-Oct-2017 on it.
regards,
Jeff
KD1IT
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Rich
I would definitely check continiuity through each winding of the receiver transformer. My 40m version looks not as neat as the higher band version in the manual, but the calibration was amazing. Its easy to solder to the outside of the insulation only, so check continuity without touching wire. When all is well, the calibration nulling is amazing. Much of the receiver is audio circuitry. Mine was intermittent so I turned on the builtin signal source,? poked around a and quickly found a loose resistor.
The test audio should be clean. Unlike some qrp rigs, the qcx has generous audio. Maybe your volume control is too high. Peaking the trimmer is not that sharp on my 40m version. But nulling the pots is very sharp, leading to amazing image rejection. Don't fear when meter jumps back up, as the number will change indicating rescaling.?
Motorboating sound does seem to imply audio is overdriven. I would check bias voltage at the regulator.
Curt
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N4TMI Coil and Resonance Tester
I just finished building and testing a coil tester that N4TMI wrote about in 73 Magazine.?
Here's a link to Alan Wolke's W2AEW YouTube channel:?
and
Here's a link to a webpage that is basically the N4TMI article reproduced with comments:?https://www.radio-collector.com/coil-resonance-tester/
Here's a photo of the board undergoing a quick test. I used a 47?H inductor and temporarily soldered a 150pF cap on. I've since changed the soldered on cap to machine pins so I can pull the cap to measure where the circuit resonates without it. I intentionally left the switch off and used machine pins per Alan's video to cut the size of the board down.
Test results
Value of the inductor per Mouser: 47?H
Value of the inductor using the the freq attained (1.84MHz) and the ARRL L/C/F slide rule: 49?H
Value of the inductor using a Keysight U1733C: 44.9?H (probably should have run it through a cal routine)
Calculated value of the inductor using the equations from the article: 49.878?H
Since I couldn't remove C1 I was not able to completely use the equations in the article.
Closeup of the board (it's pretty small). Note that you can also use an SMA connector. In fact, you can mount the SMA connector with the BNC. I right angle connector looking out the side of the board or mounted on the bottom will give you room to connect to it. You can also leave off the power jack. Just add pins or wire directly to the circuit board using the provided holes. You don't need a spectrum analyzer to measure frequency. A good counter will do the job as well as a calibrated oscilloscope.?
?
I've included a link to the Eagle files and a PDF of the schematic and board layout. SMD's are 0806 size. If you know how to use Eagle you can swap the parts for through hole. That will cause you to have to reroute the board and possibly increase the size of the board. The J310 MOSFET's were on Mouser. N4TMI used a different MOSFET and those can be found on eBay. I chose to stick with the J310's that Alan used in his video and modify the schematic to follow his (changed one resistor value).
Link to the board on Osh Park's site (no benefit to me. All cost is in what the charge):?https://oshpark.com/projects/gx7Ixj44
Link to GitHub where you can download the Eagle Files: https://github.com/Mike6158/N4TMI-Coil-Tester
It's pretty simple to determine the value of an inductor using this circuit.
--
73
NE5U
Mike
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I just completed the QCX No. 1747. I am unable to peak the trimmer cap. and the pots have no effect either. I have double checked all of the components, and rebuilt the T1 transformer. I have build several toroids before, so I am familiar with removing the insulation and checked that several times even removing the transformer and reinstalling it. The sound from the headphones sounds like a motorboat. The indicator indicated a ¡°4¡± and does not move at all. I would appreciate any pointers of things to check. I am a very experienced kit builder, so I feel confident about my soldering, etc.
Thanks and 73
Rich W4WU
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Mike
Bruce Beford N1RX
KE0IMD
Keith, G6NHU