Re: 50w PA 80m version overheats transformers?
Hi,
I have built the 80m version of the 50w PA. It works and delivers 35w at 20v supply. However, the transformers T1, T2, T3 gets hot to touch quickly when TX'ing. (dummy load or tuned antenna makes no difference) For instance, sending "CQ CQ CQ de SM4VEY SM4VEY SM4VEY" two times at 20 wpm makes them so hot that it affects the performance and I start hearing "clonks" after each dit and dah. Has anyone else experienced this problem?
Regards Jonas
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Re: #qmx #ssb CESSB update (Controlled Envelope SSB)
#qmx
#ssb
Look at Walter Wirkler’s patents on SSB/split sideband transmitters filed in 1938 and assigned to Collins Radio around 1940. ?Walter was an early engineer at Collins who I think did the sideband work as part of his MSEE work in the late ‘30s. ?
This was phasing approach which, as far as I know, Collins never used until later years because the phasing networks were difficult to replicate. ?Of course, Collins used mechanical filters ( which they didn’t invent but learned to build at reasonable
cost) to provide SSB.
Wirkler was somewhat eccentric and left Collins about the time the company started SSB work because he thought that the company used more paper than aluminum building its products. ?He continued work on a number of neat projects including aircraft control
and data link programs.
73
Jim w0nkn
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On Oct 6, 2024, at 12:21?PM, Franz Niedermeyer via groups.io <wholeflaffer@...> wrote:
?
I agree that you could emphasize an upgrade in hardware for the proposed "QSX", such that the finals can handle a greater range of abuse from the big, bad outside world of antenna systems and power sources. ?It would be yet another step forward from the
uSDX legacy.
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Thanks for all the info, my Amazon cart is getting really full. ??
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Re: #qmx #ssb CESSB update (Controlled Envelope SSB)
#qmx
#ssb
I agree that you could emphasize an upgrade in hardware for the proposed "QSX", such that the finals can handle a greater range of abuse from the big, bad outside world of antenna systems and power sources. ?It would be yet another step forward from the uSDX legacy.
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Re: #qmx #ssb CESSB update (Controlled Envelope SSB)
#qmx
#ssb
Dunno but I'll take some wine !
72,
Bill, N4QA/QRP
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Re: #qmx #ssb CESSB update (Controlled Envelope SSB)
#qmx
#ssb
On Sun, Oct 6, 2024 at 01:40 PM, Bill, N4QA/QRP wrote:
My new QMX-PLUS just took off from Charles de Gaulle Airport, headed this way !
Now the question is : will you get complimentary cheese ?
?
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Re: #qmx #ssb CESSB update (Controlled Envelope SSB)
#qmx
#ssb
For those interested, there is a new article on ESSB in the current issue of QEX magazine (September/October 2024) entitled "Class-E SSB tranmission SDR and the Dreaded Arctangent Problem" by James A.R.? Koehler, VE5FP starting on P22.? Link below.? You need to be an ARRL member and log in to read it.
-Steve K1RF
------ Original Message ------
Date 10/6/2024 8:23:32 AM
Subject Re: [QRPLabs] #qmx #ssb CESSB update (Controlled Envelope SSB)
How will the eventual QSX differ from the QMX+ once the QMX+ has CESSB? Will they be one and the same?
Very good question and one I've been giving a lot of thought to. Since QMX+ now does or will do almost everything QSX was going to do - in many cases, better - it kind of obsoletes QSX (at least in its originally intended format). When I've collected and organized my thoughts I'll post on it.?
73 Hans G0UPL
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Ideally, what you want is a soldering iron with closed loop temperature control. That is, the iron senses and maintains the desired tip temperature. That's how? you get the best of both worlds: fast heating without the tip getting too hot and damaging your boards or components.
Once upon a time, that?type of soldering tool was an expensive luxury that only a few ham builders had. Now there are affordable options, starting with the TS-100 and its relatives. The original TS-100 could only be powered with a 5.5/2.5mm barrel plug, and was usually sold with a suitable power supply. The upgraded TS-101 can be powered with either the barrel jack or USB-PD; so can the Pinecil from PINE64, a variation on the theme that ships with the open source IronOS installed. Right now the bare Pinecil is the least expensive option that is readily available (US$40 from Amazon with very fast delivery -- same day in some locations; a bit less directly from PINE64 but you'll wait); it doesn't come with a power supply, but you can use a USB-PD laptop charger. For portable use, a 12V battery or a USB-PD power bank are options; performance will be better with the power bank because it delivers more voltage so the iron heats faster. The TS-101 usually comes in a bundle that includes a power adapter that plugs into the barrel jack on the pencil.
Temperature controlled soldering stations are also popular. The ones you're most likely to see in ham shacks are the Hakko FX-888D and the Weller WE1010. (Old timers may have earlier models.) They don't perform any better (some builders say the TS100, etc are better because the tip and heater are integrated), but they have larger and easier to handle irons and the temperature controls are more convenient. Prices fluctuate, but if you want for a good deal either will be a bit over US$100. There are some Chinese clones that use Hakko tips but mostly don't copy the look of the Hakko (though full-on clones exist); they may be less than US$50 from Asian sources.
The Cadillac option is an RF-heated soldering station. Metcal invented them; there are some clones now. Super-fast tip heating, super-high price. They are a delight to use but are overkill for most builders. Metcal recently introduced a more affordable model, but it's still US$250.
(Me? I have a vintage WTCPT soldering station bought new in the 90s, a combination soldering iron and hot air station from China, and a TS-100. Plus a butane-powered Portasol that is awesome for soldering coax connectors in the field. And I have access to a makerspace with RF heated stations from Thermaltronics.)
On Sun, Oct 6, 2024 at 10:45?AM Donald S Brant Jr via <dsbrantjr= [email protected]> wrote: I suggest using only 63/37 solder with RMA flux core, from a reputable supplier.? My favorite is Multicore, Kester or Alpha are also good.? Stay far away from the lead-free alloys, they will cause you nothing but headaches.
I recommend?binocular magnification, either the traditional headworn magnifier, the newer "glasses" kind, or best and most expensive, a binocular microscope.
A variable temperature soldering station is a big help, with different sizes of tips for different uses.? Hakko and Weller are better but more costly.? I would make certain of future parts supply when considering an off-brand station.? Hint:? Many Yihua stations use Hakko tips.
I like the metal wool type of tip cleaner over the damp sponge.? Have a bottle of RMA flux handy, for when a joint needs flux but not more solder.? Isopropanol and acid brushes for flux removal.
Good luck and 73, Don N2VGU
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Re: #qmx #ssb CESSB update (Controlled Envelope SSB)
#qmx
#ssb
Yep ! Not only can they fly but they can drive too ! QMX-PLUS arrives via FEDEX truck tomorrow !
72,
Bill, N4QA/QRP
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I tried touching up the legs on IC1 to no effect.
I felt like I should try to remove the TCXO to give myself more room to work.?
That has not gone well at all. I got the component legs that were connecting the TXCO to the main board to drop out but seems like the pads on the two boards are still soldered together. I’m trying to mop up with solder wick but not having much luck and everything is looking pretty burnt.
?
Desoldering is not as easy as they make it look on the YouTube! ?
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HI Roy.??
Here's a maybe too long reply, but I like cheerleading for the 'solder-blob' enamel wire removal method.
Didn't mean to repeat several of the good suggestions already sent your way, but I had it all typed out. :)
Chris' pics are a good start for the basic tools you'll need.
The special micro lead clipping tool is almost a must for good results. Check out the Hakko's on Amazon.?
A PCB Holding Stand will make the job go easier and faster.?
I HIGHGLY recommend Kester Tin/Lead (Sn/Pb) 63/37 Rosin Core solder. You can't go wrong with it. I use 0.031 diameter wire in general but will also use 0.020 diameter wire depending on the size of the joint and if there are nearby pins or other pads that might be easily bridged. The 1 ounce packs should be enough for a kit or two.
I've also had excellent results in the past with Radio Shack Tin/Lead/Silver solder. AND, its back, being made in the USA again. Not cheap, but well worth it.? Note: some folks say rework for joints made with silver bearing solder is harder, but I've never had a problem.?
You'll likely want some Solder Wick. I use the 2mm width for almost everything.?
And, consider getting some ChipQuik liquid flux. It will come in handy for tough joints and rework. I dab a bit on solder wick to help the 'pull' reaction go faster and better.
99% Isopropyl Alcohol is the best for flux cleanup. Costs a lot more than 91% but works WAY better. A pint should last a long, long time.
I can highly recommend the WEP 882D soldering/hot air station. (Pic from Amazon attached to this message.)?
I've built 3 QMX series kits, 3 50W Amp kits and several Dummy Load, SQP/PWR meters and other useful test kits using this station.?
The solder that came with it is less than stellar. I chucked it. The non-magnetic tweezers are great. I used them successfully when replacing small SMDs.
I used the medium sized conical tip for almost all joints and the larger screwdriver tip for joints that go to the ground plane, especially on two QMX+ kits, to be able to put more heat, quickly on those joints. I did test the broad, flat knife tip for the solder blob method wire tinning (but much prefer my Weller 100P - see next and below). I ordered some extra ultra fine conical tips and used them to successfully practice SMD soldering techniques on IC packages with very small pin spacing.?
TOROID PREP
A general tip I've shared previously is to definitely use the 'solder blob' method to remove enamel from toroid winding wire BEFORE final insertion and soldering into the circuit.? ?I see a LOT of folks on the group who have had to chase down bad toroid lead solder joints because the enamel wasn't fully burned off. And I believe anything that helps reduce excessive heat time for electronics components leads and surrounding areas is generally a very good thing.?
So here are some excerpts From a Toroid Preparation Guide written years ago by Michael Fisher WT9W, where I first learned of this technique.?
*
PREPARING THE LEADS
Now that you have wound the toroid it is time to prepare the leads.? First you must determine how the toroid is to be mounted on the board (laying flat or standing vertical).? You will then need to mark the wire leads using the fine tip black Magic Marker (Sharpie).? I mark the leads at the edge of the toroid just before the lead would hit the pc board when the toroid is mounted flush.??
(NOTE: I personally mark the wires from the bottom of the PCB with a fatter tipped Sharpie then have learned to guesstimate and burn back the enamel a bit further to account for the thickness of the PCB plus just a bit more. If you do this, be sure to clean off the Sharpie ink around the solder pads on the PCB with some Isopropyl Alcohol before soldering!)
REMOVING THE ENAMEL AND TINNING THE LEADS
A soldering iron can also be used to remove the enamel.? The method works best with a temperature controlled iron or workstation.? If you can adjust the temperature on your iron, you will want to set it between 750 and 800 degrees F.? If your iron has removable tips, put on a larger tip then you would normally use for pc board soldering.? The larger tip will hold more solder and will maintain a more constant temperature during the enamel removal process.? To start removing the enamel, melt a large blob of solder on to the tip.? The solder should melt almost instantly and should remain molten on the soldering iron tip.? Next, run the wire slowly through the solder on the tip until you reach the mark you had put on the wire.? ?You will see the enamel being removed and the wire being tinned at the same time.? The solder will retain the ash from the enamel.? This will require you to clean the contaminated solder off of the soldering iron tip and melt fresh solder on to the tip frequently.
*
I have built many 'toroid dense' kits over the years. I have used Michael's method and never had a problem with a solder joint for a toroid.
I use an old Weller W100 soldering iron normally used by stained glass workers. I clamp it horizontally to the edge of my work bench with either 'wide' side of the tip facing up. I also use a doubled over layer of heavy duty aluminum foil underneath the tip area.?
That iron is still available. There are look alike clones out there but I've seen some really bad reviews for those. Its not cheap, but not really awfully expensive especially if you think you'll be using it a lot. Mine is about 20 years old and the original tip is still working fine.?
Feed solder onto the tip with one hand to build up a nice blob of hot solder on the tip then feed in the wire ends with the other hand slowly until the enamel is burned off back to the mark made earlier (and a bit more - see the NOTE above). Its useful to be ready to feed in some extra solder sometimes.?
I do find that thicker wire might need a scrape or two with an X-Acto knife edge to give the solder some bare wire to 'bite' on to start the burn off reaction with this method.? I keep a small, wet kitchen sponge nearby and wipe the soldering iron tip clean frequently.?
Give it a try. Experiment on some extra wire to get some practice before committing to its use on actual kit components. I think you'll find it works great!
And in general . . . .?
Take your time, inspect, clean and re-inspect each joint as you go along. I do ohm meter checks where detailed and many other joints too.?
73 GREG KI4NVX
Greg McCain
gamccain50@...
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On Sunday, October 6, 2024 at 08:43:45 AM EDT, Chris KB1NLW via groups.io <chrisrey1@...> wrote:
From a presentation I made to my local club.
?
For de-soldering Solder wick possibly in conjunction with Quick Chip ( a special low temperature solder that lowers the temperature of an existing solder junction - see videos )
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On Fri, Oct 4, 2024 at 06:17 PM, Stan Dye wrote:
Note that the general power-on process is this:
1 - pressing the power-on button turns on Q103/Q105, which puts the voltage from the input jack on the +12V rail
2 - this +12V goes to the input of IC101 which creates the initial 3.3V VDD voltage via D103, which is also connected at the top of D109.
3 - this VDD voltage powers on the CPU
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Thank you Stan.? I now have some hope that the problem may lie with the power circuit.
1 - When I press the power on button I see +12v on the +12v rail.
2a. I measure 2.17v on IC101 Vo pin and 1.2v on Vdd.? My measurements are with a digital meter measuring voltage so may not be precise.
Are there any further checks that I can make before replacing D109?
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Re: Automatic Antenna Tuner, Internal Battery with a charger and built-in speaker for QMX+. Open Source.
?
Looks like a great addition to the QMX+!!! Partly on the same topic... If you happen to have an Elecraft T1 tuner and want to control the saved band settings from your QDX/QMX you can look into some python code I just got working for my Rock 4 SE single board computer: ?? This is work in progress since the CAT control of the transceiver occasionally get lost, but the script does the job apart from that. Basically the script is polling the present frequency via hamlib rigctld, and any change of band will be sent to the Elecraft T1 which will switch to the memorized band setting accordingly.? My guess is that the code is even easier to set up on a Raspberry Pi. Will try that soon. I would have wished that the N7DDC Ali Express tuner was able to save band settings too... that would have been a much cheaper alternative. I hope the code can be useful for someone. Any improvements or new ideas are appreciated.
?
73 Anders SM0HPL
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Re: #qmx #ssb CESSB update (Controlled Envelope SSB)
#qmx
#ssb
I didn't know they could fly now too, but at this rate I would not be terribly surprised if that was a firmware upgrade as well...??
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I suggest using only 63/37 solder with RMA flux core, from a reputable supplier.? My favorite is Multicore, Kester or Alpha are also good.? Stay far away from the lead-free alloys, they will cause you nothing but headaches.
I recommend?binocular magnification, either the traditional headworn magnifier, the newer "glasses" kind, or best and most expensive, a binocular microscope.
A variable temperature soldering station is a big help, with different sizes of tips for different uses.? Hakko and Weller are better but more costly.? I would make certain of future parts supply when considering an off-brand station.? Hint:? Many Yihua stations use Hakko tips.
I like the metal wool type of tip cleaner over the damp sponge.? Have a bottle of RMA flux handy, for when a joint needs flux but not more solder.? Isopropanol and acid brushes for flux removal.
Good luck and 73, Don N2VGU
?
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Re: #qmx #ssb CESSB update (Controlled Envelope SSB)
#qmx
#ssb
On Sun, Oct 6, 2024 at 07:23 AM, Hans Summers wrote:
When I've collected and organized my thoughts I'll post on it.?
?
Could you consider these for the QSX:
?
- More robust PA that tolerates accidental mismatches better then the '170's
- Wider range of allowable DC input voltage
?
Thanks/73,
?
--
John AE5X
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Re: Automatic Antenna Tuner, Internal Battery with a charger and built-in speaker for QMX+. Open Source.
Sardar,
Congratulations to you and the hams who helped on this amazing effort. It's a fabuluous addition to Hans' QMX+ xcvr.
I hope that this becomes a group build and a forum is established to support it.
Many thanks to you all for your efforts!
73,
Larry,? K3PEG
Super nice! I hope the custom menu and GPIO controls are not far off in Hans’s roadmap, so we would not need the extra button.
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Re: QMX practice mode suggestions
Great thread. Given where we are with FW 1_00_27, what is the best way setting up CW practice, especially muting RX noise?
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I have a couple of extra torids for this project. ?I didn’t find them readily available, so ordered extras. ? When you start your build, get a hold of me if you want one.
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Bill, N4QA/QRP
Shirley Dulcey KE1L
Kevin MW0KXN
Donald S Brant Jr
Chris Raine W3PB