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Re: Known issues on uBITX r4
#ubitx
hirosmb JAZZ
¿ªÔÆÌåÓýIC. I¡¯ll pay my attention to this distorted audio issue for a while.Any other known hardware problems on uBITX r4, the latest board? Many thanks, MVS. // hiro
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Re: Known issues on uBITX r4
#ubitx
There are few members who reported? the good functioning of Audio amplifier. ?we need to check whether the element is wrong in design or some pieces went? out with distorted output. Regards MVS Sarma ? On Fri, Jun 29, 2018 at 9:44 AM, hirosmb JAZZ <hirosmb@...> wrote:
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Re: Noise Burst
#bitx40
Installed raduino v1.27.1 and it works fine. No RF noise burst on transmit. Great piece of software Allard.?
Now looking to do more hacks of the hardware to take full advantage of the software features. 73 -- John VK6JAH |
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Re: Known issues on uBITX r4
#ubitx
¿ªÔÆÌåÓýJack, Thanks for ur quick reply. Does the r4 board still need to be fixed for the distortion issue? // hiro
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Re: Known issues on uBITX r4
#ubitx
Jack Purdum
Most of the mods that have been made are summarized at: ubitx.net Jack, W8TEE
On Thursday, June 28, 2018, 11:31:43 PM EDT, <hirosmb@...> wrote:
Hi, all. I¡¯m really new to uBITX and planning to place my order to hfsignals.com very soon. Then please share its known hardware issues of uBITX r4 that I need to modify or solder. Thanks in advance and hope to QSO with my uBITX soon. // hiro, JJ1FXF |
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Known issues on uBITX r4
#ubitx
Hi, all.
I¡¯m really new to uBITX and planning to place my order to hfsignals.com very soon. Then please share its known hardware issues of uBITX r4 that I need to modify or solder. Thanks in advance and hope to QSO with my uBITX soon. // hiro, JJ1FXF |
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Compiler warnings
Jack Purdum
All: Several people have asked about compiler warnings they are getting, like: ????????warning: ISO C++ forbids converting a string constant to 'char*' A variation on this are the "deprecated" warnings issued by the compiler. Even more confusing is the fact that the warnings they now see were not there before. Usually, this is because of a compiler update. As a general rule, compiler warnings do not prevent the compile from finishing or performing an upload. However, warnings mean something is bending the rules. For anyone who might be interested, this was my answer to one of those people.
Steve: I think everyone understands what a syntax error is: Not following the rules of the language. Semantic errors are more difficult because the rules are followed, but the context is wrong. For example, we know an English sentence needs a noun and a verb...those are the rules. However, if I say: "The dog meowed.", it obeys the syntax rules, but the semantics are out of context. I'm not sure how far back, but around version 1.65 the GCC compiler
started performing some syntax and semantic checking at the "lint"
level. My company produced a C compiler back in the '80's and we had a "picky flag" that could be set from 0 to 10. It performed syntax and semantic checks at increasing stringent levels. I never saw any published C code that passed our Picky Level 10. Indeed, that level was so intrusive that we never used it. Most work was done at Picky Level 4. When we were ready for distribution, we cranked it up to level 10. Truth be told, we still didn't bother to fix some of the warnings. Somewhere between 1.65 and 1.85 they kicked the GCC compiler's equivalent of our Picky Flag up a notch, hence warnings now where none existed before. That's a good thing. However, the bad thing is that there are now a lot of warnings that unnecessarily cause people concern. Even worse, a lot of it comes from libraries, which is NOT your responsibility to fix. The library writer should fix those. When I first compiled the ?BITX code, I had probably a hundred such warnings, mainly because I insisted on using only one INO file, making all the other CPP files (plus a header). True, it was a pain in the butt to fix all the warnings, but it was worth it. Why? First, by not using multiple INO files, the compiler cannot perform data type checking. You'd be surprised by how many bugs hide under the blanket of missing type checking. Second, because the compiler no longer has to glom all the source files into one huge file to compile it, it allows the GCC to perform incremental compiles. This is a HUGE win. When I compile the JackAl code for the first time in the morning, it must recompile all files. In the process, it clears the "dirty flag" for each source file. Even with my 8-core, 3.7GHz machine with a mega-munch of memory, the JackAl code takes almost 2 minutes to compile. If I used all INO files, it would always take 2 minutes to compile the source code regardless of how many file changes I made. With incremental compiles, it sets the dirty flag and recompiles only those files that have changed since the last compile. This drops my compile time (on a single-file change) to about 5 seconds. Given that I might do 30-50 compiles a day, you do the math Kind of a long answer, but it's important that you understand what's going on "under the hood" from time-to-time. Usually, compiler warnings can be ignored, but always keep in mind it still means the compiler saw something it didn't like. Jack, W8TEE
On Thursday, June 28, 2018, 7:13:32 PM EDT, Steve Smith <steve@...> wrote:
thanks - I erased the EPROM and then calibrated and I am getting real results. These were new part so I am not sure how the EPROM would have had values, but the first few times we loaded the software we did not have an SD card in. Could that have affected it? Also, thanks for the explanation of the warnings, Jack. I am running version 1.85 of the Arduino IDE on Windows 10. Is there a reason some folks get the warnings and others don't? Is it a setting in the IDE? 73s Steve |
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Re: RFI from uBitx TX after AGC and other mods installed
Mark M
After I sent this it dawned on me to check the 12v supply as well. Sure enough, it's there too. FWIW, I'm powering it off a 20A Astron 13.8v linear power supply and feeding it into my old Heathkit Cantenna dummy load.
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I have it installed in one of the amateurradiokits.in cases. The power wiring runs very close to the antenna connection and the final amp transistors. I tried twisting the wires tightly but it didn't make any difference. If I disconnect the final amp supply line it goes away and there's no noise from the speaker with the AGC board in place. Anyway, a couple more observations... Mark AA7TA On 6/28/18 5:07 PM, Mark M wrote:
Don... |
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Re: RF power chain mods and improvements..
One last thing, testing CW uses none of the IF and modulator so if it works you can't know if the IF is fine.
MUST test using SSB.? Ideal bias for Q20 will have the collector at about 6V (+-1V).? To high or low and it functions poorly.? ?In mine the 3904s had it at 3.5V, that is too low.? This is typical of normal variations across different device lots devices.?? Allison |
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Re: RF power chain mods and improvements..
R23 change yes and 18 ohms may be too low still.
Likely operating point, R21 may be too low. Before you go to band pass filters try one thing... pain to install, Low pass filter between the junction of pins 5 and 3 on t2 (IF port of the first mixer) and R27 and c16 (the junction of the RX/TX 45mhz amps).? The low pass filter is for 45mhz cut off I use .176uh (5turns on t30-6) and 68pf on each side (pi section). This is the only thing that seems to help with the spur and enough to be ok if the drive is not excessive.? If the TIA is getting excess out of band or distortion the spur is bigger the filter helps (about 3-6db).? Sample size of one can't prove it.? Worth a try if you can measure the results before and after.?? Allison |
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Re: RFI from uBitx TX after AGC and other mods installed
Sure does, Mark. Now to find where it's coming from. Please check the 12 volt input pin of the Raduino's 7805. See if it is there, too. On my AGC boards I don't have ANY bypassing on the 5 volt feed and still don't hear anything. But my 12 volt is well filtered. Could be the difference. -Don
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Re: RFI from uBitx TX after AGC and other mods installed
Mark M
Don...
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I finally had a chance to start looking into this on my ubitx (I'm seeing the same issue). I managed to borrow a scope and putting it on the 5v supply seems to indicate that you're right. I see up to about 40 mv p-t-p on the 5v line when xmitting SSB with the AGC board not connected at all. It's pretty clean in receive. I'm tapping into the 5v line on the raduino. So that certainly looks like the smoking gun. Now to figure out how it's getting in there... Hope this helps... Mark AA7TA On 6/28/18 12:30 PM, Don, ND6T via Groups.Io wrote:
... It seems that |
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Re: Latest Build, Mods and results.
CIRCUITBOARD DETAILS.
Hello Alan. Thanks for your interest. Attached is a wiring diagram (more useful than another schematic), an underneath view of the circuit board which should help with your construction. The relays are the same as used on the uBITX board i.e. HFD27-012-S available on eBAY. The pots are 100 ohm available on eBAY. The 100 ohm resistor functions as the "pot" for 10M since this has the lowest output and runs flat out. This is actually a very simple mod to do and work FANTASTICALLY.? Mike N6CMY |
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Re: RF power chain mods and improvements..
Thank you Allison for the clarification. I read the thread about the mixing problem and understand where the problem is. |
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Re: Latest Build, Mods and results.
M Garza
And that was the wrong link... Sorry Here is what the link should be: Marco - KG5PRT On Thu, Jun 28, 2018 at 2:36 PM M Garza <mgarza896@...> wrote:
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Don, ND6T
Gwen Patton
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