On 2025-05-17 07:23, Terrance Robertson, KN6ZDE via groups.io wrote: If you want to purchase several instruments, consider Digilent's
Analog Discovery 3 [1]. *** Cool instrument. I like that it has all those extra analyzers. Not very fast at 125Msamples/second though. It should be able to do up to 30MHz on the scope. I have a Hantek 2D72. It's a scope/DMM/AWG. The scope is 250Megasamples/second if you're using one probe. 125 if you're using two. The Arbitrary Waveform Generator is good to about 25MHz. I have created a file for it that turns it into a two-tone oscillator for testing SSB transmitters. Doesn't have all those other analyzers though. Cheaper - now $169 on Amazon. The Hantek has become my favorite scope, because it's just so small & convenient. And I have *lots* of scopes. After buying the Hantek, I found the OWON HD272S, which costs about $15 more, but has a larger screen & a better multimeter. - Jerry, KF6VB
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If you want to purchase several instruments, consider .? At about 4"x4"x1", it's great if you don't have a lot of space.? It includes the following instruments:
- Oscilloscope
- Waveform Generator
- Power Supplies
- Voltmeter
- Data Logger
- Logic Analyzer
- Pattern Generator
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- Static I/O
- Spectrum Analyzer
- Network Analyzer
- Impedance Analyzer
- Curve Tracer
- Protocol Analyzer
- Script Editor
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I recommend the Pro pack which includes probes and a BNC adapter which increases the bandwidth.
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I have a similar signal generator, but the brand is "FeelElec" and the model is FY6800.? ?I have used it extensively for SSB transmitter testing.? It also functions as a pretty good frequency counter.
It's not a laboratory grade instrument.? But for general purpose use on the bench, it's quite a bargain.? I don't see the same problem as Oliver, as the amplitude can go down without noticing significant noise or distortion,
at least for basic SSB testing.? And it does generate quadrature tones at audio frequencies, so you can drive a QSE.? This generator will be very useful for T41 transmitter tests if it performs like mine.
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Strongly recommended is a TinySA Ultra spectrum analyzer.? You need to get the Ultra, because the regular TinySA does not have enough resolution to distinguish SSB tones.
But even with that, the scan is extremely slow.? You should also get a 50 watt rated attenuator of 30 to 40 dB, and a collection of smaller attenuators.? 10 watts is +40 dBm, so
you need at least 40 dB of attenuation to keep from blowing up the spectrum analyzer during transmitter testing.? An alternative is a directional coupler and attenuator.
A collection of SMA cables of various lengths is helpful.
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I believe the TinySA Ultra was upgraded recently, however, the scan speed is still very slow.? My TinySA Ultra includes an RF signal generator.? Very useful!
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I tried using an SDRPlay as a spectrum analzyer.? It works, but it was a hassle to use.? The TinySA Ultra was much easier to deal with on the bench, and it doesn't require a computer.
In my opinion a spectrum analyzer is a bare minimum needed to tune up a phasing type SSB transmitter.? Ultimately I purchased a Siglent spectrum analyzer VNA combo which is a really amazing instrument.
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For tuning filters, a NanoVNA is extremely helpful.? Another bare minimum, but in my case the Siglent VNA has proved to be far superior.? But you will pay $$$ to get that.
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--
73 Greg KF5N
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Don't forget that most junior colleges and universities have EE departments, or at least physics depts that have all the test equipment you'd ever need. You can take your T41 to their labs and use their equipment. Just ask permissions of the dept head, tell them you are a licensed ham radio operator, what you want to do, and ask when would be a good time. I would even take a photo of the T41 with you so they know it's a serious radio. If I were running a lab, I would make your task a "teachable" moment as part of a lab. Even some high schools have robust test equipment.
Jack, W8TEE
On Saturday, May 17, 2025 at 07:32:35 AM EDT, John Owens K1JO via groups.io <johnowenschina@...> wrote:
[Edited Message Follows]
I'm looking for test equipment suggestions. I have an oscilloscope, DVM, LCR meter but need enough equipment to at least finish this T-41...doubt I will live long enough to build anything more complicated ;-)
In the DSP and SDR book they mention an audio signal generator with quadrature and a spectrum analyzer. Any suggestions on models that won't break the bank but are sufficient for building, testing and tuning the T-41?
Anyone advice on this signal generator, not sure if it can generate quadrature? https://www.amazon.com/Professional-Generator-Seesii-Precision-Dual-Channel/dp/B08T9H9FBY/ref=asc_df_B08T9H9FBY?mcid=b9e572b8f8e63e6fbdcf4c21c805b61f&hvocijid=15043490532578762466-B08T9H9FBY-&hvexpln=73&tag=hyprod-20&linkCode=df0&hvadid=721245378154&hvpos=&hvnetw=g&hvrand=15043490532578762466&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9002666&hvtargid=pla-2281435177858&th=1
-- Jack, W8TEE
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I have that signal generator and it isn't great. It's very noisy for low amplitude (<100mV) signals. It is useful for some quick tests, but you can't trust it at low signal levels. I've not tried to generate quadrature signals with it, not sure if its capable.
I've had some success using my computer's sound card as a quadrature signal generator for audio frequencies, but the DAC is not fast enough for fully testing the T41.
On Saturday, May 17th, 2025 at 7:32 AM, John Owens K1JO via groups.io <johnowenschina@...> wrote:
[Edited Message Follows]
I'm looking for test equipment suggestions. I have an oscilloscope, DVM, LCR meter but need enough equipment to at least finish this T-41...doubt I will live long enough to build anything more complicated ;-)
In the DSP and SDR book they mention an audio signal generator with quadrature and a spectrum analyzer. Any suggestions on models that won't break the bank but are sufficient for building, testing and tuning the T-41?
Anyone advice on this signal generator, not sure if it can generate quadrature? https://www.amazon.com/Professional-Generator-Seesii-Precision-Dual-Channel/dp/B08T9H9FBY/ref=asc_df_B08T9H9FBY?mcid=b9e572b8f8e63e6fbdcf4c21c805b61f&hvocijid=15043490532578762466-B08T9H9FBY-&hvexpln=73&tag=hyprod-20&linkCode=df0&hvadid=721245378154&hvpos=&hvnetw=g&hvrand=15043490532578762466&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9002666&hvtargid=pla-2281435177858&th=1
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I'm looking for test equipment suggestions. I have an oscilloscope, DVM, LCR meter but need enough equipment to at least finish this T-41...doubt I will live long enough to build anything more complicated ;-)
In the DSP and SDR book they mention an audio signal generator with quadrature and a spectrum analyzer. Any suggestions on models that won't break the bank but are sufficient for building, testing and tuning the T-41?
Anyone advice on this signal generator, not sure if it can generate quadrature? https://www.amazon.com/Professional-Generator-Seesii-Precision-Dual-Channel/dp/B08T9H9FBY/ref=asc_df_B08T9H9FBY?mcid=b9e572b8f8e63e6fbdcf4c21c805b61f&hvocijid=15043490532578762466-B08T9H9FBY-&hvexpln=73&tag=hyprod-20&linkCode=df0&hvadid=721245378154&hvpos=&hvnetw=g&hvrand=15043490532578762466&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9002666&hvtargid=pla-2281435177858&th=1
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Ok once we get rolling ill let my son take over the booth and ill come see you¡
Dr.?William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com
email:??bill@... ?
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On May 15, 2025, at 8:22?PM, Tim via groups.io <w4yn@...> wrote:
? I am set up in parking lot where Ecom trailers are, just behind them, W472 and W473, 2 white canopies (if they survive storms tonight)
I have the the 3pin jumpers, and will try for a runner to run some to Dr. Bill, bad hip here prevents much wondering.
I have lots of vintage HF and some Icom vhf and uhf rigs, 2m hill topper (rare) a Tar heel screw driver and a Mosley Mini 33AW 20-10 including WARC bands.
Some qrp rigs and other STUFF!!
Tim W4YN
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I am set up in parking lot where Ecom trailers are, just behind them, W472 and W473, 2 white canopies (if they survive storms tonight)
I have the the 3pin jumpers, and will try for a runner to run some to Dr. Bill, bad hip here prevents much wondering.
I have lots of vintage HF and some Icom vhf and uhf rigs, 2m hill topper (rare) a Tar heel screw driver and a Mosley Mini 33AW 20-10 including WARC bands.
Some qrp rigs and other STUFF!!
Tim W4YN
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I am currently at Hamvention with a plethora of boards and kits. ?All set up in booth #2607 just across the floor from ICOM. ?
Dr.?William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com
email:??bill@... ?
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Thanks Oliver.? I'll do it the way you recommend. dave
This is a part of the code that I've not dug into in detail, so reader beware.
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If I understand the code correctly, you would need to do the following steps in order to have the default values in the code be those specific to your rig:
1) Put your values into this function:
2) Uncomment this line:
3) Compile and upload.
4) Recomment this line:
5) Compile and upload.
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Now your default values will be save to the SD card. Hopefully that's right. I wouldn't recommend doing this however -- it's better to save the EEPROM values to your SD card after calibration and then restore them after a reflash using the EEPROM menu.
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On 2025-05-14 16:51, Oliver KI3P via groups.io wrote: -- it's better to save the EEPROM values to your SD card after calibration and then restore
them after a reflash using the EEPROM menu. *** A common time to need to do this is when upgrading to a newer software. I worry about the SD card or EEPROM format changing and the SD write or read turning into gibberish. - Jerry, KF6VB
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This is a part of the code that I've not dug into in detail, so reader beware.
?
If I understand the code correctly, you would need to do the following steps in order to have the default values in the code be those specific to your rig:
1) Put your values into this function:
2) Uncomment this line:
3) Compile and upload.
4) Recomment this line:
5) Compile and upload.
?
Now your default values will be save to the SD card. Hopefully that's right. I wouldn't recommend doing this however -- it's better to save the EEPROM values to your SD card after calibration and then restore them after a reflash using the EEPROM menu.
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Oliver can probably tell ya. ?I believe its done by JSON so its raw data.?
Dr.?William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton - J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com
email:??bill@... ?
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On May 14, 2025, at 11:40?AM, D Solt via groups.io <davesolt@...> wrote:
? Jack, did you ever send out details on how to store the cal data on the SD Card?? I can't figure it out.? My SD Card shows "no files" when I connect it to my PC.? I know that you are at FDIM, so no rush.
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I see the power cal section, line986, in EEPROM.cpp, but the factors are around 0.030 while my cal data adjustment for power is in the 20-40 dB range
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I am confused as to where the RXIQ and TXIQ cal data is stored in EEPROM.cpp.? I see the simplified V12HW at line 1037.? Is there a place to store the individual bands numbers?
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Thanks for your help
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dave, n3ds
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Thanks Jack!? I'm reading the chapter in the book now.
On 2025-05-14 08:02, D Solt via wrote:
> Jack, did you ever send out details on how to store the cal data on
> the SD Card?? I can't figure it out.? My SD Card shows "no files" when
> I connect it to my PC.? I know that you are at FDIM, so no rush.
*** There is a choice in the EEPROM menu - write EEPROM data to SD.
? ? ? ? ? ? - Jerry, KF6VB
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Thank you Jerry.? Got it saved now!
On 2025-05-14 08:02, D Solt via wrote:
> Jack, did you ever send out details on how to store the cal data on
> the SD Card?? I can't figure it out.? My SD Card shows "no files" when
> I connect it to my PC.? I know that you are at FDIM, so no rush.
*** There is a choice in the EEPROM menu - write EEPROM data to SD.
? ? ? ? ? ? - Jerry, KF6VB
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 See the 4th Main Menu option (EEPROM).
Jack, W8TEE
On Wednesday, May 14, 2025 at 11:02:42 AM EDT, D Solt via groups.io <davesolt@...> wrote:
Jack, did you ever send out details on how to store the cal data on the SD Card?? I can't figure it out.? My SD Card shows "no files" when I connect it to my PC.? I know that you are at FDIM, so no rush.
?
I see the power cal section, line986, in EEPROM.cpp, but the factors are around 0.030 while my cal data adjustment for power is in the 20-40 dB range
?
I am confused as to where the RXIQ and TXIQ cal data is stored in EEPROM.cpp.? I see the simplified V12HW at line 1037.? Is there a place to store the individual bands numbers?
?
Thanks for your help
?
dave, n3ds
?
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-- Jack, W8TEE
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On 2025-05-14 08:02, D Solt via groups.io wrote: Jack, did you ever send out details on how to store the cal data on
the SD Card? I can't figure it out. My SD Card shows "no files" when
I connect it to my PC. I know that you are at FDIM, so no rush. *** There is a choice in the EEPROM menu - write EEPROM data to SD. - Jerry, KF6VB
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Jack, did you ever send out details on how to store the cal data on the SD Card?? I can't figure it out.? My SD Card shows "no files" when I connect it to my PC.? I know that you are at FDIM, so no rush.
?
I see the power cal section, line986, in EEPROM.cpp, but the factors are around 0.030 while my cal data adjustment for power is in the 20-40 dB range
?
I am confused as to where the RXIQ and TXIQ cal data is stored in EEPROM.cpp.? I see the simplified V12HW at line 1037.? Is there a place to store the individual bands numbers?
?
Thanks for your help
?
dave, n3ds
?
?
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Hi All - I hooked up 3 brand-new D cells and got 4.81V.? I measured 3 cases, as shown on the graph.? It included the new battery case, as well as 10mH feeding a 100 uF ceramic.? They all look the same except the battery which is better below about 100 Hz.? For the frequencies of our I-Q radios there is nothing to see.? Above a few hundred Hz we are not power supply limited, it would seem.?? No, I don't know what that weak junk is around 5 kHz.? It wasn't there last week!? Looks a bit like an idle tone.
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Hey, Hi Mike, great to see you here. Yeah, we don't want to count the years that we go back!? But good stuff.
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Re: New SI5340-based RF Board in development
Larry, thanks for the pointer. The UHFSDR design is highly informative.
j
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jjpurdum
John Owens K1JO
K9HZ