Another path to take, if you already have a 50 ohm dummy load, is to use that instead.? You will need to calibrate the system in that case.
I am working on a version of the DDL using a SparkFun, Microview module in place of the Arduino board and display and an MFJ, 300W Dry Dummy Load.? I am also adding a Peak power function to the sketch and a bootup option to enter the reference power reading and have the system self-calibrate.? It is in the 'breadboard' stage at this time and I will post the code, etc. when I have packaged it up and tested it in that form.
Dennis KG4RUL
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Re: QSX 10W HF Linear PA kit
I use a indelible marker to color the leads.
You can use an inductance meter to check, the higher one will be 3T ..
Raj
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At 28-10-18, you wrote: Hello from the rapidly warming and drying out downunder.
I have got as far as winding the transformers and installing them. My method for remembering which was the three turn and which was the two turn winding of T204 was to leave the tails of the three turn winding appreciably longer than the tails of the two turn winding. Now I have this transformer in my left hand, it has two windings, one has longer tails than the other. Now is it the three turn or the two turn winding? I should have written it down!
I have to comment on the excellent quality of the assembly manual. Well done and thanks, Hans!
vy 73 all.
Kevin VK3DAP / ZL2DAP
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Re: QSX 10W HF Linear PA kit
Hello from the rapidly warming and drying out downunder.
I have got as far as winding the transformers and installing them. My method for remembering which was the three turn and which was the two turn winding of T204 was to leave the tails of the three turn winding appreciably longer than the tails of the two turn winding. Now I have this transformer in my left hand, it has two windings, one has longer tails than the other. Now is it the three turn or the two turn winding? I should have written it down!
I have to comment on the excellent quality of the assembly manual. Well done and thanks, Hans!
vy 73 all.
Kevin VK3DAP / ZL2DAP
--
Kevin B. G. Luxford
kbgluxford@...
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Mouser has 2,837 of the 1k 3W Xicon in stock, item number 283-1.0K-RC
They don't really have to be 1k, there are plenty of other choices.
For example, get the same part at 1.2 k, item 283-1.2K-RC
and use 1200/50 = 24 of them in parallel instead of 20.
If all you ever expect to feed it is 18 watts or so, maybe use 300/50 = 6 of? ?283-300-RC
You wouldn't even need that oil bath, just good air flow.
Other values that might? be of interest:? 51? 100 150 200 300 510 750
Jerry, KE7ER
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On Sat, Oct 27, 2018 at 07:53 PM, Jack Purdum wrote:
A number of you have written me privately saying you're having trouble finding the 1K 3W resistors for the dummy load project (Nov., 2018, QST).
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All:
A number of you have written me privately saying you're having trouble finding the 1K 3W resistors for the dummy load project (Nov., 2018, QST). If you don't have access to QST, you can download the assembly manual from our site:
Evidently, some eBay suppliers say they have them, but the order quickly becomes a back order. Check before you order. Someone just wrote to me and said Arrow carries them:
but they are saying a December delivery. I bought mine from Rich at communications-lab.com:
You may want to write first, as he was moving his business to HI when we last spoke. Also, if you know that you're always going to be using QRP power levels, you could cut back on the wattage and that should make them easier to find (and cheaper).
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Re: Nextion Basic 3.2 Display will not update
#ubitx
I'm replying to an old post, much of it was about SD cards with the Nextion displays (for those that use email, not the web).?
I got a 4.3" Nextion Enhanced display for a non-bitx project and tried HC and HC-I SD cards to get it to load the firmware.? All of the attempts were made formatting the cards as VFAT32 from Linux, all were dismal failures.
What I finally had to do was format one in my wife's laptop (long format) to get it to recognize it as VFAT32.? Also what I did to avoid having to format it like that again was to use dd and make an image of the blank, formatted card.
The first one I tried to use was just an HC.? No go. The display still didn't like it. The second one was an HC-I card.? That one worked.? Also that one was formatted using the above mentioned image.?
I hope this helps someone else that may encounter similar problems.
Vince - K8ZW (using the group's web interface)
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Re: QSX 10W HF Linear PA kit
Having built a few already RTFM is valid.? It is compact so take time and check everything.
Allison
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Re: SolderSmoke Podcast #207 uBITX 15 Mtrs, 60 mtrs, homebrew, antennas, Cubesats
Thanks for telling me about the DX contest and that 15 was opened. Just got D4C , MonteVerde , which seems to be off the coast of Africa, an Island ? 5 watts, uBITX !? 80 meter loop with an antenna tuner ? No, not possible. can't be. Love Solder Smoke. Trying to get people to listen as they travel.?
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Thanks.?? I will try that.?? Im not 80 yet,? just 76,? but eyes and shakes etc seem 100. ? ? Sent from for Windows 10 ?
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From: Michael ShreeveSent: Saturday, October 27, 2018 11:46 AM To: [email protected]Subject: Re: [BITX20] Nervous #ubitx-help ? Yes, I'd say its the soldering that's pretty much the only challenge. I have one friend whos in his 80s and he is challenged by soldering now. Couple of things, 1 is shaking. The way to be successful if you shake is, wrap the wires your trying to solder, do not "tack" the wires together or try to. Do not TACK wirer to connections on jacks or plugs. Wrap the wire first. 2 . Use the best magnifying glass you can get, one with a table mount, those spring mounted ones that are cheap now on Ebay. They used to use Fluorescents, not they use led lighting and are light weight. I even took a ring mount light and put it on a large magnifying lens handheld,? that had a handle and used to have batteries in the handle and an incandescent flashlight bulb for light. Upgraded it, love it. Magnification and lighting will extend your construction activities tremendously, especially, generally, if your older and have those old eyes that require reading glasses ? VERY COMMON, not to worry !
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Chinese on-line retailers sell electrets with external amplifier on a 15x20mm board complete with separate 5 pin header.? This unit seem to be very effective for BITX radios.? Past week? I received 2 pcs .
Frank? ,? EI7KS
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Re: SolderSmoke Podcast #207 uBITX 15 Mtrs, 60 mtrs, homebrew, antennas, Cubesats
Thanks for posting that, something to listen to. 1000 watt ubitx all band. LOL
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Yes, I'd say its the soldering that's pretty much the only challenge. I have one friend whos in his 80s and he is challenged by soldering now. Couple of things, 1 is shaking. The way to be successful if you shake is, wrap the wires your trying to solder, do not "tack" the wires together or try to. Do not TACK wirer to connections on jacks or plugs. Wrap the wire first. 2 . Use the best magnifying glass you can get, one with a table mount, those spring mounted ones that are cheap now on Ebay. They used to use Fluorescents, not they use led lighting and are light weight. I even took a ring mount light and put it on a large magnifying lens handheld,? that had a handle and used to have batteries in the handle and an incandescent flashlight bulb for light. Upgraded it, love it. Magnification and lighting will extend your construction activities tremendously, especially, generally, if your older and have those old eyes that require reading glasses ? VERY COMMON, not to worry !
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SolderSmoke Podcast #207 uBITX 15 Mtrs, 60 mtrs, homebrew, antennas, Cubesats
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I have just used Allan'sdownload file V1.92-3.5 for tft loading to micro SD card.
All looks well but there is not any sound. I wonder as this is a work in progress if this an
unresolved problem or have I managed to cause the problem. Any help with this would
be appreciated
Regards
Fred Aunger
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Ruarto
Recognize that much of the assembly is soldering wires. First take some time having fun to identify the version, and how it goes together. The ubitx has a prominent set of 4 relays, compare pictures. Perhaps examing the parts may convey that you can assemble it. Maybe you can work with a local ham if you later need to. Its an opportunity to enjoy radio, one step at a time.
Curt
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? I have been lurking and trying to follow these treads and am getting real nervous.? ? I am elderly and not that proficient of a electronic tech,? don¡¯t have oscilloscopes, etc.??? I was told it was ready to work just needed to be assembled.???? Was I wrong? ? Am I in trouble here? ? I have about everything,? case, board, etc¡.???? but now am wondering if I should perhaps get someone younger (less shakey) and with more electronic and radio savvy to assemble it for me for a fee. ? ? I got this a couple months ago,? and think its possibly a bitx40 not a 20.?? Or basic ubitx.?? ? Any suggestions?? ? ? ? ?
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This tells me that there is a fault BEFORE the first mixer. High probability is a shorted
trifilar transformer. I found one such case by rocking the toroid and there was a jump
in SSB power.
Check the 45MHz L5 and L7 for bad connection. You can check for continuity with a
multimeter.
Most probably the fault is somewhere common to RX and RX.
Good luck, faults are usually very simple.
Raj
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At 27-10-18, Evan Clark (OSC) wrote: Thanks for the help everyone. I am now seeing over ten watts out when keying CW. Still need to fiddle with the SSB as I have no power out there. I also have some issues with the audio, I think that's just due to incorrect tune up but it seems way off. Thanks for everyone's help!
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Re: QSX 10W HF Linear PA kit
I use one that came with a Dremel. Small and handy.
I found the holes for the 0.6mm wire to be a tight fit. After making
bifilar
transformer the lead wires will not be straight and they struggle to
get through the kit pcb holes.
Hans can keep this in mind!
Half kit done, rest later!
Raj
At 26-10-18, you wrote:
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On Thu, Oct 25, 2018 at 11:21
PM, Glenn wrote:
another small issue..... all holes in the heat-sink have burs on
them.
You want to keep it FLAT as the devices have to be flat to it for best
heat transfer.
Burs are easily removed with a precision knife (Exacto or similar).?
A good builder
checks for accidental shorts prior to power up.
FYI the bigger thing is that the FBxx-2402 ferrite have sharp edges on
the holes
and can strip enamel from wires while winding.? I use a small cone
shaped
Carborundum stone to take the edges of the holes down.
Allison
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I hope you are not trying it with the K3 on the same bench.? You will fully overload (even the K3). it will give you wrong readings. - f
On Sat, Oct 27, 2018 at 2:26 AM Timothy Fidler < engstr@...> wrote: Forgot word to the wise? - TEF for what it is worth strongly advises against making Allard hardware mods with Original Farhan software/firmware in place. Or? ?you may go to hell in a hand basket with all sorts of issues? and? people like Maestro? Allard may have trouble working out where the hell you are. I Suggest you try to get out of current hole before you try to reflash the nano uP (if that is what you might think of next) .? People have been down that route and ended up with no tcvr at all (you really need a second Raduino to be sure you have a backout path).. ..or live dangerously.
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Ah, good to hear!
Jerry
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On Fri, Oct 26, 2018 at 04:29 PM, Evan Clark (OSC) wrote:
Thanks for the help everyone. I am now seeing over ten watts out when keying CW. Still need to fiddle with the SSB as I have no power out there. I also have some issues with the audio, I think that's just due to incorrect tune up but it seems way off. Thanks for everyone's help!
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Raj vu2zap
Michael Shreeve
