Date   

Re: Source for replacement parts in small quantities?

Vernon Matheson
 

Look up Kits and Parts on the inet...

Vern

On 2020-08-02 00:01, W5EGA@... wrote:
Does anyone have a good source for small quantities of parts here in the US? I need to buy a replacement resistor but I don't have a need for 100 of them? I would prefer it be a US based company to cut down on shipping times and costs. 


Boost module with 50 W Amp?

w2eck
 

I posted this a while back but never saw a reply. Also know subject has been up several times before. Thinking about trying the 50w Amp kit. Wondering if this Boost module with work to power the amp
https://www.amazon.com/DROK-0-5V-30V-Adjustable-Regulator-Transformer/dp/B07XC66XF6   it will do the necessary voltage but just 4amps. 

anyone using a similar boost module?

73 Paul W2ECK 


Source for replacement parts in small quantities?

W5EGA@...
 

Does anyone have a good source for small quantities of parts here in the US? I need to buy a replacement resistor but I don't have a need for 100 of them? I would prefer it be a US based company to cut down on shipping times and costs. 


Typo in the QCX+ manual 1.02

W5EGA@...
 

Just noticed a typo and wanted to add it here for correction in later revisions...

Under the section "3.59  Install 10K resistor R46" the color code has the 10K resistor listed as "brown-black-black-brown-red" but it should read "brown-black-black-red-brown".



(Also, just noticed that you spelled "colour" wrong.... I'm joking!) 


Re: How about an ultra-portable "QCX mini" version? #qcx

DL2ARL
 

coming back to the root of this thread...

The rig that fits all the wishes of the many, that rig will be an expensive one and will by no means be available on a $50 budget; this seems self-evident.  If all wishes would have to be included, Hans would have to sell a rig as big as a refrigerator and expensive as a sports car.  You can google for such: there's plenty of them out there and I never thought there is so much money in the world to buy them all. So I am not asking from Hans to include yet another feature, just because I happen to like it that way! What he is doing is smart enough as it is and the number of kits he has produced in a fairly short time is proof enough.

The qCx+ has been increasing in volume, but in the right way. Now it offers plenty of room into it's housing for experiments of all sorts, and it also offers plenty of room inside for a battery and maybe even a tuner of some sort. So putting all together, the "bigger" qCx has gotten smartly smaller. I never enjoyed the "official" case of the old qCx because of the obvious reason that it was a fit that was too tight for my liking. The new concept perfectly meets my needs and even if I would like it smaller, it getting bigger lets me make it smart so that it shrinks again to a higher level of portable efficiency.

Think of a grab'n go rig, one that you can take with you even if the odds of having time for a qso are neglectible. A rig that is always ready. Don't think towards some disciplined and highly organized SOTA or highgrade ambitious dxPedition. Think of a rig you might like and love to carry with you even when going shopping for shoes with your spouse. Now think of them in that fancy shoe shop having more that one pair of shoes and of those even more in different shades of the same color that beg to be carefully assessed in front of a mirror and you having by this a spare minute in your car with some kind of casual antenna on the roof...

This never happened to you? It did to me. I had the rig handy the smart small one, all self contained, battery loaded, ready to be flipped into use. But I seem to have been sleeping at that time and probably just dreaming.

Yours friendly, Razvan DL2ARL

PS: regarding the dreaming near the shoe shop: a smart fellow (was it Friedrich Schiller?) once said: The whole life is a dream; hence being wise means having pleasant dreams.


Re: How about an ultra-portable "QCX mini" version? #qcx

DL2ARL
 

Hello group!
the idea of a SMD rig to reduce the size of a qcx to fit the need of ambitious sota activators is welcome and a great idea indeed. After having built several if not almost all the kits offered by kd1jv I must say that even the manufacture of the rig is easier in SMD if you have the tools and the patience to do so: with SMD you do not have to place the component on one side of the pcb and turn it upside-down to solder it in place from behind. A HUGE improvement!

BUT! Be aware that even the smallest rig, let it be only of the size of an ONEr (one square inch) will be a PAIN to use if
...when connected to all it's periphery it will resemble to a patient on intensive care (to quote Steve wG0AT).

Any yet so small rig out there in the green will need... a battery, will need ... a key, will need some sort of hearing aid, will most likely need an antenna too and this last source of sorrow will also probably love to be tuned of some sorts...

so that there will be lots and lots of cables, connectors, wires and gadgets around, all begging to be forgotten at home, lost somewhere between rocks, in a shallow river or in the bottom of your trousers pocket...

Didn't you experience that Tarzan-howl feeling when standing at the desired portable spot you find out that you forgot your headphones in the car or the cable between the tuner and the rig just got broken, the 3.2 to 5.1mm adapter for the power supply seems to be hiding somewhere in the backpack and  key fixture just dropped between two boulders so that you can still see it, but no chance to get it back up except if turning the mountain over your head.

However small the rig might be, if it is not self contained with all it's periphery, it will be a pain to use out there in the green. This is why I always envy those happy Ee'le-kraft guys that only slip their kayExxTwofer out of it's poach, throw a wire over some bushes, flip a switch and there they go. No wires, no pain and even a microphone are they allowed to enjoy that's built into their rig, just wirelessly begging to be  bespoken.

And there is some other issues: for a rig meant to be of real portable efficiency, it's power consumption has to be carefully optimized. It does not make much sense for example to use a low voltage LiPo battery, painfully, noisefully and loosily boost the voltage up to 12V to keep the PowerAmplifier happy and on the other hand waste the energy with a 7805 linear voltage converter to meet the 5V need of the digital part and of the receiver.

A power management of some sorts has to be implemented into the rig from an early stage of it's development so that it allows for separate power supply rails for different consumption needs. This way the low voltage, low power part of the rig could be fed directly from a small battery pack and the power division could receive a higher voltage either out of another battery pack or via some sort of more or less noisy DC-DC power converter which does not disturb the receiver.

Yes, it is easy to speak, easy to tell the others what they should do
and it is harder to go to the workbench and get the things done, but I just allowed me here to think loud for a moment.

If your intention is just having an ultra- small rig, in this case splendid designs of kd1jv are still commercially available in different flavors and bandwidths. One can't get  much smaller than that and even the efficiency has been taken care of! But you still end up with a box that is surprisingly small for the features it contains,  but that is so small that it is difficult to handle and after having set everything together, power supply, key, antenna tuner and some sort of hearing aid, you end up with that wG0AT patient on intensive care I already mentioned having wires and adaptors sticking out of all of his openings...

Not nice at all. I found solution for this too, by fixing everything with elastic bands to a plastic board that fits into a lunch box. But it's still a pain and usually I loose more time setting the whole up than I am allowed to spend qso-ing. And afterwards I have to put everything neatly back where it came from, which ends up ugly, because things seem to have swollen up during use and fit no more into the cases they came from.

Think of all this wishing yourself a rig that is so small you can no longer use it because it's too small in the wrong way. At least for me, it has to be of some kind of smallness that is SMART, not of a smallness that's just small.

Tell me more!

Yours friendly, Razvan DL2ARL


Re: QCX/QCX+ CAT Rig Control? #cat

Gregg Myers
 

Yes, the time can bet set via CAT. Look at the responses to “Setting time via CAT command #qcx” in the forum from a day ago.

73,
Gregg W7GRM

On Sat, Aug 1, 2020 at 3:58 PM Podolsky A <w8du@...> wrote:
I meant to ask....is there a way to set the time on the rig via CAT? I do not have the GPS module.
Tnx de Arnie W8DU


Re: #qcx T1 mounting instructions QCX+ #qcx

Phil/K3UT
 

I flex there is another run of boards, I think all the confusion of T1 holes could be eliminated if the hole numbers could be screened right on the board. 

Half way through building my QCX+. My third build in the Q series. The build goes lots faster when the resistors are flat mounted!

Phil, K3UT 


Re: QCX/QCX+ CAT Rig Control? #cat

Podolsky A <w8du@...>
 

I meant to ask....is there a way to set the time on the rig via CAT? I do not have the GPS module.
Tnx de Arnie W8DU


Re: QCX/QCX+ CAT Rig Control? #cat

Podolsky A <w8du@...>
 

Tnx Alan. Looks pretty easy. Just have to get a TTL to USB level converter.
73 de Arnie W8DU


Re: Qcx 40 no RF output

Maurizio
 

Dear Alan, thank you for your advice. What values ​​should I detect on transistors?
Maurizio


Re: #qcx T1 mounting instructions QCX+ #qcx

Ben
 

Yes I wrote about it in this message: 

Op 1 aug. 2020 om 21:40 heeft Terrence Ryan <terry@...> het volgende geschreven:

I can't find any references to this in the messages, but the last step for mounting the leads of T1  (P23, step(15)), says to put the remaining end of secondary 3 into hole 2. However, hole 2 was populated in step (8) which is the other end of secondary 3. The lead is right at hole 1, which is the only remaining hole of the 8, so I'm inclined to think it's a type. Can anyone confirm that? Also, is there a link to a general errata?
73, Terry n3fih


Re: Advice re solar power? - One More Parameter, Temperature

Jim Manley
 

Hi Bob,

I was able to download the full file and yes, I knew to look at it in Presentation mode.  I have to say that the animation didn't add much that moving my eyeballs to focus on the numbers to the right in the chart hadn't already accomplished.

I'm not just one of those skoolhowse edumacated injuneers who, six munse uhgo, cutn't evun spall injuneer, and now I are one!  I do agree with you about instructions, but I'm a rare engineer who actually writes instructions that can be understood even by technicians!  I started doing hands-on stuff at 12 years old, where most technicians intellectually stagnate.  Just remember, if it weren't for us engineers, you techs would still be screwing your nuts (as self-satisfying as that might be), trying to make square wheels turn easier by adding more suspension lift pressure until you blew a gasket, and walking around muttering to yourselves, "Mr. engineer said, 'Pie are squared.'  Pie are squared?  Pie are not square, pie are round.  Crumb cake are square!" 😝

At least neither of us are mathematicians.  If you haven't heard about the test to see who was smarter, an engineer or a mathematician, where a clock on a wall and a recliner in a room were involved,  I'll send you that one off-list.  Antifa is everywhere, these days.

I'm very glad to hear that you survived and are mending from your brain tumor removal.  That would make most humanities majors completely useless, instead of mostly useless!  Make sure you ask your brain surgeon if you'll be able to play the violin, and when he says, "Yes!", you can say, "Great!  I never could before!"

And ... scene!  The next performance of the Mighty Carson Art Players will feature Henry WIllis, Mel Tillis, Ernie Ford, Chevy Chase, Chase Manhattan, and Spot the Wonder Dog in "To Kill a Mocking Nerd".  Look for it in another random thread somewhere here on the QRP Labs Support Group and Group Grope Mental Therapy Club!



Jim  KJ7JHE
Lame Deer Montana High School Amateur Radio Club  KJ7JKU


On Sat, Aug 1, 2020 at 8:26 AM Bob Ballard <bobnmarji@...> wrote:

Jim,

 

LOL!  Danged Engineers … I had to deal with a raft of you guys during my almost 40 years in Aerospace Defense.  The sad reality is that the bulk of Engineers actually believe that they are so much smarter than non-Engineers that they consistently fail to consider anything they don’t initiate.  They also “Doan need no stinkin’ Instructions!” (consider the scene from “The Treasure of the Sierra Madre”) and wouldn’t follow the Instructions if they read them anyway!

 

 

You did put the attached file in PowerPoint Presentation mode per my initial message’s clearly stated Instruction, right? -“(put it into Presentation mode to run the animations properly)”.    

 

If you (unlike most Engineers) did follow the Instructions and the animations simply didn’t work which is a likely event because the initially attached file left my computer at 712 KBs,

attached above is a non-animated version of the presentation that should address the failure of the initial attachment (hopefully this one will arrive intact).

 

I concede; you win the hottest and coldest environment descriptions contest.      

 

 

As far as nurse behavior,  I’ll refrain from describing my brain tumor removal on June 5, 2020 beyond the 6.5 hour surgery, 3 days in ICU, 10 days in rehab with incredibly caring nurses that treated me like a beloved member of their family.  However, I still have low energy output that they tell me will take a few more months to return to “normal” (no permanent brain damage though thank God).

 

 

FWIW – I think we both have wasted enough time with our respective rants so I’m ending my participation with this one unless the attached file also fails to function normally.  Feel free to fire the final “get the last laugh” round and/or carry on all by yourself if you like.  Your great sense of humor and the laughter is certainly worth the time it takes to read it.

 

 

73,

Bob – KG5SQJ

 

From: QRPLabs@groups.io <QRPLabs@groups.io> On Behalf Of Jim Manley
Sent: Saturday, August 1, 2020 1:50 AM
To: QRPLabs@groups.io
Subject: Re: [QRPLabs] Advice re solar power? - One More Parameter, Temperature

 

Hi Bob,

 

When I tried to open your presentation, which shows here that it's 306 KBs, there was only one page.  It had a static chart showing panel power horizontally, and it had the 100 watt column circled in red.  Not exactly the most informative and exciting PowerPunt presentation I've ever seen, and I've seen some doozies.  I've been using PP since it first ran only on Macs in black and white (not even gray-scale), well before its inventors-founded Forethought was bought by Microsloth.  So, no, I didn't get to witness any whiz-bang animations or much more information than the numbers and letters on that chart.

 

As far as the connecting cable goes, it doesn't contribute to the warming of the cells, just a reduction in the power delivered, which will vary all over the place with the in situ setup.  So, it's not a factor for this discussion.

 

I don't doubt that high temperatures reduce output - I can vouch that my output goes to about zero in anything hotter than about 75 F, or lower then about 65 F, as I have low blood pressure and high metabolism.  When I was in an ICU overnight, the nurses told me to breath faster, because I kept setting off the low-breathing-rate alarm that could only be set down to 10 breaths/minute.

 

I was asleep when it was happening, and I asked them how I was supposed to breath faster while I was asleep.  They said that they didn't care how I did it, just do it!  When I proposed certain kinds of strenuous exercise with them in positions detailed in the Kama Sutra, they suddenly didn't seem so interested in my well-being.  Never tick off a nurse, especially ones monitoring you in an ICU when you're asleep!

 

If you want to try hot, go to the Persian/Arabian Gulf on a haze-gray Navy ship with black carborundum non-skid deck areas, or anywhere on the black, six-inch thick, HY-120 steel hull of a submarine.  The seawater injection temperature into the condenser of the engineering plant in that bathtub of a body of "water" is routinely well above 90 F, and that's the source of "cooling" for the vast majority of equipment on the ship .. including the crew!

 

On the other hand, we have five fingers (for now - the night is young), and there are some places I can invite you to visit in Montana in the Winter, and stick your tongue on the frame of a solar panel while witnessing the cells' vastly-improved performance.  Can you spell "Ralphie" from "A Christmas Story", in the scene with the flagpole out in front of the school?  Actually, it gets cold enough there that your tongue can get stuck to the cold air if you stick it out!

 

 

Jim  KJ7JHE

Lame Deer Montana High School Amateur Radio Club  KJ7JKU

 

 

On Fri, Jul 31, 2020 at 9:43 PM Bob Ballard <bobnmarji@...> wrote:

LOL!  Please note my comments below.  No whining nor griping … just all in fun!!!  😊

 

73,

Bob – KG5SQJ

 

From: QRPLabs@groups.io <QRPLabs@groups.io> On Behalf Of Jim Manley
Sent: Friday, July 31, 2020 7:52 PM
To: QRPLabs@groupsio
Subject: Re: [QRPLabs] Advice re solar power? - One More Parameter, Temperature

 

Hi Bob,

 

I assume that the temperatures are ambient _at_the_cells_ and not the ambient air temperature around the outside of the panel, which could easily be two very different things, depending on a lot of other very different things.  Being under glass, and with the cells made of a darker material (mounted on a dark background?), you could have quite a little oven cooking things.

Oh c’mon Jim!  You didn’t really fail to read what the presentation said, did you?     

The presentation indicates the cell temperature in several places.  For example, note the text highlighted in the first animation -  “the solar cell itself, not the surrounding.”.

  

Also, although I suspect it's a much smaller contribution, the current flowing through the cells and the connecting conductors have their own resistances, which means they're each also a contributor to heat, and it's all under that glass, so the air surrounding the cells will get that much warmer.

Yup!  And so do the losses attributable to the 40’ of AWG 10 solar system cable necessary to keep the solar cells out in the sun as long as possible and me and my radio under the trees and in the shade!

  

Being an engineer, I realize that the thermodynamic model for this is already the kind of thing that a massively-parallel, high-performance computing system was built to execute.  So, the $64,000 / 64 KW question is, has anyone done that, or at least done in situ measurements at enough points in a typical assembled panel to provide yet-another interesting graphic?

I’m not an Engineer so I obviously yield to your educated and experienced expertise on this subject.  Nevertheless, with the ambient air temperature above 95°F I have tested my two 100 Watt solar panels that I use to charge 12v Bioenno BLF-1220A 20aH  Lithium batteries.  I use the twin 100 Watt panels to charge each battery one at a time while the other battery is running my 100 Watt Kenwood TS-690SAT radio on Field Day.  When aligned directly at the sun, each solar panel produces approximately 65-70 Watts to an 80% discharged battery using Genasun GV-10-Pb-12V MPPT charge controllers (no RFI).  And yes, I know this system is a ridiculous overkill for this QRP thread but that is the only solar system I currently use.

If you think the solar panels won’t get hot enough to reduce their 100 Watt rated output that much, try briefly touching one of those shiny aluminum solar panel frames after it has been sitting in the hot Texas sun at 95°F (or more) air temperature for 2-3 hours.  And, as you stated above, the much darker Monocrystalline cells will absorb even more heat than the shiny aluminum frame.  And heaven help you if the frame you touch is one of the black powder-coated models (sizzle!)!  FWIW - If the wind is blowing they do work somewhat better because the air flow will slightly reduce the cell’s temperature.

  

Another brain fart that just escaped my cranium is, could small(er) fans be used to circulate cooler air (the ambient air has to be cooler than what's under the glass, even in 100 F Texas conditions, right)?  For a big enough solar panel array, could pumping subterranean-cooled water up (and warmed water back down) further increase the efficiency of the panels?

Yes that would work but what is the “big enough” point of diminishing returns where the cooling system consumes more energy cooling the cells than the cells produce to meet the need?  And this rabbit hole declines even more considering we should be focused on just enough solar power to charge batteries required to run QRP radios.

 

  

If this is feasible and hasn't been patented, I hereby lay claim to this being original prior art, with complete drawings, specs, computer models, etc., available for inspection at my QTH (I'm also a patent-holder :)  Now, you just need to figger out where, exactly, I am to see it all! 😃

Sounds good to me!

 

Thanks and  

Jim  KJ7JHE

Lame Deer Montana High School Amateur Radio Club  KJ7JKU


Re: No 5 volts

N3MNT
 

Two more solder joints to check.  Is there still no 5V with front board disconnected?


Re: #qcx T1 mounting instructions QCX+ #qcx

Ronald Taylor
 

Terry, in the instructions and in the photos both of those holes are labeled and referred to as “2”. If you match the numbered photo to the numbered instruction it’s clear where the wire goes. And you are correct. It’s the only remaining hole and right where the only remaining wire from the toroid is located. 

Ron

On Sat, Aug 1, 2020 at 12:40 Terrence Ryan <terry@...> wrote:
I can't find any references to this in the messages, but the last step for mounting the leads of T1  (P23, step(15)), says to put the remaining end of secondary 3 into hole 2. However, hole 2 was populated in step (8) which is the other end of secondary 3. The lead is right at hole 1, which is the only remaining hole of the 8, so I'm inclined to think it's a type. Can anyone confirm that? Also, is there a link to a general errata?
73, Terry n3fih


Re: No 5 volts

sean <kc2lwx@...>
 

Any closer  shots of the solder side of the board

De kc2lwx 
Sean



On Sat, Aug 1, 2020 at 4:21 PM, ajparent1/KB1GMX
<kb1gmx@...> wrote:
Since 5V is used in more than a few places on the board Id assume short
maybe at the regulator but anywhere is possible.

Allison
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Re: No 5 volts

ajparent1/kb1gmx
 

Since 5V is used in more than a few places on the board Id assume short
maybe at the regulator but anywhere is possible.

Allison
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Re: Linear amps for SSB taking 3.5 W up to 45 W - half decent Ebay offerings.

ajparent1/kb1gmx
 

Well finally someone that realizes that the RDparts are not ne plus ultra 
or anything other than expensive.  Several other tried and had to work
like mad to get to 20W barely.  Doing RF power uising LDmos fets at
12V is not high performance or terribly linear.
 
He didn't sell many at all.  Its not even in his retired list.  I barely remember it
from 2010.

At high power layout is everything.  

Allison
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Re: Linear amps for SSB taking 3.5 W up to 45 W - half decent Ebay offerings.

Hans Summers
 

Hello Tim

I'm not sure the use of a common bias resistor is as bad for linearity as you think. But until someone measures it and we have quantitative data to discuss there's not a lot to say. 

Aa far as replacing single devices, I'd never recommend that anyway. I think in several places in my documentation I recommend always replacing all transistors in the PA at the same time with devices from the same batch. This applies to the Ultimate3S PA (if using more than  one transistor), or the QCX/QCX+, 50W PA, or the driver and final stages of the 10W Linear. All the devices used are so dirt cheap anyway that it makes no sense to take risks for the sake of penny pinching. 

I don't believe it is significantly easier to design around an RD15HVF1 than an IRF510. The RD has some marginal benefits but I don't think they anywhere near justify the 10x higher price tag. 

The 10W Linear kit http://qrp-labs.com/linear costs $26. The 50W QCX/QCX+ PA costs $29.50. If using RD-series and the kit prices were doubled, but the performance pretty much the same, I doubt the QRP Labs kits would be so attractive. 

73 Hans G0UPL 


On Sat, Aug 1, 2020, 21:26 Timothy Fidler <engstr@...> wrote:
Hans

with all due respect to the superlative CW design I think they will find out about the limitations of the common bias design. Since you buy your Mosfets from a common supplier for quality reasons it won't be as bad as it could be but that raises the issue what happens in the case of a field replacement.  I'm going to be cheeky and put photos of a French implementation of a US design in the Files area of this wunnerful (sic ) site.  Bear in mind though it is called a 45 W PEP design (the French jobbie) that back calcs to be about 11 W Rms , which is typical of IRF510s run in linear mode on a nominal 12V.  The amp design shown could be greatly improved by making it a dual bander via a send LPF which would be relay selected. An even   swisher mod would be to have the board designed with Vias so that either the RD16HH or the IRF510 could be used by connecting the appropriate strapping via Cu wire. (The board would need to be DSided for this to be simple).


Re: #linear Amps and non-linear Amps #linear

ajparent1/kb1gmx
 

Interesting  two amps at the link one does 100W the onter near 50..
THe 100W unit uses 10in a 5x5 push pull and does about half the
power of my 4x4 6M (220W at 28V) unit with the same IRF510s. 
That's pretty poor power for 28V amp. 

The WA2EBY design is near 21 years old since publised.  I built
it in 2006 and its been solid since runing about 45-55W on all
bands save for 10M where its 37w.  But it does it with two irf510s.

Both of mine are linear so long as they are not over driven.

Also both have to be built so they are stable at about 100ma
or more per device.

Allison 
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