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Re: What to do when a selftest fails

 

Does the counter show any DC on its input, and is the tinySA’s input cap now shorted?

I had mine at what I think is maximum output (-18 dbm) for 45 minutes feeding my scope without a probe and then I tee'd in a 50 ohm input frequency counter and that killed the AS179-92LF input switch. It took a few seconds, I was watching the scope and the signal decayed within 5 seconds of hooking up the counter.
Bob
Re: What to do when a selftest fails

 

Reggie,
?? How were you using it at time of failure??
?I had mine at what I think is maximum output (-18 dbm) for 45 minutes feeding my scope without a probe and then I tee'd in a 50 ohm input frequency counter and that killed the AS179-92LF input switch. It took a few seconds, I was watching the scope and the signal decayed within 5 seconds of hooking up the counter.
Bob


On Wednesday, February 19, 2025 at 08:10:33 AM PST, Terry Perdue via groups.io <k8tp@...> wrote:


> ? That is why a DC Block is such an important part of your test kit. It is just a capacitor in series with the centre conductor in an SMA-M to SMA-F adaptor.
> Make sure it has a DC rating of at least 100V, preferably 200V. Many of the units on Ebay, etc are only rated at ~20V DC isolation.
> HTH Someone...Bob VK2ZRE

With a higher voltage coupling cap, isn’t damage still likely due to the voltage spike as it is connected to a >5V source? I’m sure Erik would have used a higher voltage cap if that weren’t the case.
Re: What to do when a selftest fails

 

The tinySA input capacitor support inputs well below 100 kHz.
This implies large capacitance in very small form factor which is not available for high voltages with acceptable cost.
A separate DC block can be much larger and may not have to support low frequencies.
Make sure you put at least some attenuator between the DC block and the tinySA input to prevent DC buildup
--
Designer of the tinySA
For more info go to

Re: What to do when a selftest fails

 

? That is why a DC Block is such an important part of your test kit. It is just a capacitor in series with the centre conductor in an SMA-M to SMA-F adaptor.
Make sure it has a DC rating of at least 100V, preferably 200V. Many of the units on Ebay, etc are only rated at ~20V DC isolation.
HTH Someone...Bob VK2ZRE
With a higher voltage coupling cap, isn’t damage still likely due to the voltage spike as it is connected to a >5V source? I’m sure Erik would have used a higher voltage cap if that weren’t the case.
Re: What to do when a selftest fails

 

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That is why a DC Block is such an important part of your test kit. It is just a capacitor in series with the centre conductor in an SMA-M to SMA-F adaptor.
Make sure it has a DC rating of at least 100V, preferably 200V. Many of the units on Ebay, etc are only rated at ~20V DC isolation.
HTH Someone...Bob VK2ZRE

On 18/02/2025 10:51 pm, hwalker via groups.io wrote:

On Tue, Feb 18, 2025 at 12:14 AM, Reg Du Toit wrote:
I bought my SA ultra from Zeenko Aliexpress
It was fine and passed all tests and calibration then
I have only used it as a signal generator and did not upgrade (v1.4 156)
While testing a transceiver I noticed the output level from the SA ultra was low so this is what I've done
Did a self test and it fails on #3 and goes no further
?
Tests 3 checks the 30 MHz CAL OUTPUT signal level.? If it is failing, try the following troubleshooting steps:
?
1.? Connect the CAL OUTPUT (top connector) to the RF INPUT (bottom connector).
2.? Select MODE:Calibration Output:30MHz
3.? Select Spectrum Analyzer
4.? You should see comb lines with the main carrier at 30 MHz @ ~-35.6 dBm.
5.? If you don't see any comb lines or comb lines with a carrier at 30 MHz well below -35.6 dBm then you either have a defective attenuator (U38:PE4312C-Z) or RF input switch (U22:AS179-92LF).
6.? Select LEVEL:LNA
7.? If you now see comb lines with the main carrier at 30 MHz @ ~-35.6 dBm then the RF input switch is working, and you have a defective attenuator.? Selecting LNA switches out the attenuator and switches in the low noise amplifier.
?
When the tinySA Ultra is used as a signal generator it is subject to reverse voltage or turn on/turn off transients from the device it is connected to.? The only reverse voltage protection the tinySA Ultra has is its ESD protection diode.? That diode is not meant for overload protection.??
?
I learned my lesson on a $5000 RF generator.? Thankfully the tinySA doesn't cost nearly as much.
?
Herb
?
Re: What to do when a selftest fails

 

On Tue, Feb 18, 2025 at 10:31 PM, Reg Du Toit wrote:
Here are the results
?? The SA indicates a level of -75dBm at 30MHz
?? Switching on LNA the signal is gone completely
It does look as if the LNA is faulty but not to sure about the attenuator
I did a attenuator test and the green line was straight although also at a very low level
Maybe the input switch is also faulty
?
? ?Assuming your unit was damaged while in the signal generator mode, the LNA was not in the signal path.? Either just the RF switch is faulty, as was the case for Bob, or also the attenuator.? I would purchase both and swap out the RF switch first.?
?
I keep a spare set of these three components on hand to cover most repairs:
?
- Input RF switch U22: XA17-G4K or AS179-92LF
- LNA U14: BGA2817
- Attenuator U38: PE4312C-Z
?
Herb
?
Re: What to do when a selftest fails

 

Herb many thanks for your reply
?
Here are the results
?? The SA indicates a level of -75dBm at 30MHz
?? Switching on LNA the signal is gone completely
It does look as if the LNA is faulty but not to sure about the attenuator
I did a attenuator test and the green line was straight although also at a very low level
Maybe the input switch is also faulty
?
Bob many thanks for your input
?
Regards, Reg
?
?
?
Locked Re: Attenuation for Ultra

 

On Tue, Feb 18, 2025 at 09:03 PM, W0LEV wrote:
I just tested my Baofeng BF-F8HP and the Quanseng UV-K6 HTs both at high-power using 40 dB of attenuation into the HP 8568 spectrum analyzer.? Transmit frequency for both was 442.275 MHz.? Here are the results:
?
Baofeng:?? Spurs:? ± 280 kHz @ -40 dBc? (depending on frequency - varies to less than -60 dBc)
????????????????? Harmonics:? Second:? -50 dBc,? Third:? -60 dBc
?
Quansheng:? Spurs:? ± 280 kHz @ -30 dBc? (same comment as the Baofeng)
????????????????????? Harmonics:? Second:? -50 dBc,? Third:? -65 dBc
?
Interesting..I've not had a look at the close in stuff (yet)
?
?
?BTW:? The Quansheng is my favorite of some six HT's.? Do I use them all?? No.? Do I need them all? No.? The Kenwood TH-F6 is some 14+ years old.? The Kenwood TH-D74 is the newest to me, but was willed to me by a deceased ham/friend.? The Alinco DJ-G7 is got to cover L-Band and is roughly 18 years old. ???
?
Seems we have a community of HT collectors on here ;-)
?
The Quanger is a good EDC HT here, but it does have a few limitations, like
FM broadcast breakthough on 2m in *some* circumstances.
?
The Bangfang doesn't suffer from FM broadcast breakthough.
?
I have briefly tested the Yaesu VX7R and like yourself I also have an Alinco DJ7
so that I can use 23cm. (Dreadful menu system on the latter in my opinion).
?
On TX they are cleaner, but cost a hell of a lot more.
?
But hey, we're comparing $20 HT's to $500 etc stuff.
?
Both categories are good enough on TX.
?
On RX the expensive ones do win, but we don't always need the extra
RX performance, but then sometimes we do :-)(
?
73 de Andy
?
?
?
Locked Re: Attenuation for Ultra

 

I just tested my Baofeng BF-F8HP and the Quanseng UV-K6 HTs both at high-power using 40 dB of attenuation into the HP 8568 spectrum analyzer.? Transmit frequency for both was 442.275 MHz.? Here are the results:

Baofeng:?? Spurs:? ± 280 kHz @ -40 dBc? (depending on frequency - varies to less than -60 dBc)
????????????????? Harmonics:? Second:? -50 dBc,? Third:? -60 dBc

Quansheng:? Spurs:? ± 280 kHz @ -30 dBc? (same comment as the Baofeng)
????????????????????? Harmonics:? Second:? -50 dBc,? Third:? -65 dBc

Certainly they both have filtering.? The Quansheng is a bit cleaner in harmonics, but both show -50 dBc on the second harmonic.?

?BTW:? The Quansheng is my favorite of some six HT's.? Do I use them all?? No.? Do I need them all? No.? The Kenwood TH-F6 is some 14+ years old.? The Kenwood TH-D74 is the newest to me, but was willed to me by a deceased ham/friend.? The Alinco DJ-G7 is got to cover L-Band and is roughly 18 years old. ???

I have to believe these measurements would have been much the same if I had used one of my TinySAs. ?

Dave - W?LEV? ?

On Mon, Feb 17, 2025 at 5:46?AM VK3DPM Dave via <davepm=gmail.com@groups.io> wrote:
Hi Andy,
Fair enough. I also tested a Baofeng, Quansheng & VX7R. The results were similar to yours. I don't think the Baofeng radios have much or any filtering, whereas the Quangsheng (UVK6) and VX7R do. On another forum some talk about using the UVK6 at 30Mhz?and around 1Ghz. Using the tinySA I only measured in the mW region & sensitivity was crap as well. You can approximate sensitivity with the tinySA using a modulated tone and backing off the level to the point it just disappears into the noise then add 12dB.?

Dave??

On Sun, 16 Feb 2025 at 20:20, Andy G0FTD via <punkbiscuit=googlemail.com@groups.io> wrote:
On Sat, Feb 15, 2025 at 11:18 PM, VK3DPM Dave wrote:
I like your test and description, however I suggest at least a 10W 1st attenuator, should have at least double the power capability as attenuators can get hot and their resistance / attenuation can also change.
Agreed. But for the sake of completeness I was actually using a 10w 1st attenuator, not a 5w
as I previously stated (my typo). Actually the 10w version looks like the 5w version but just
with an added heatsink shimmed on to it ;-)
?
The 10w 1st attenuator is actually raised a few degrees too.
?
I also note with your baofeng test that you measure -31.6dBm if you add the 70dB of attenuation means the input power to the 1st attenuator is 38.4dBm which is around 6.9W. Something isn't right, I doubt a 5W handheld puts out nearly?7W, mine certainly doesn't. If everything is correct then your first attenuator is being overloaded which is not good.
?
The plots were a simple *average* of four sample, no max hold.
I just held the PTT until the plot was stable "enough" for a quick
check. That probably accounts for the approx 1.5db variation.
?
Just for fun I did do a quick check of my Yaesu VX7R using slightly
tweaked Tiny SA Ultra params.
?
That rig was cleaner, worst sprog was down at the -65db level.
But then again it did cost about 15x as much ;-))
?
73 de Andy
?



--
Dave - W?LEV
Re: What to do when a selftest fails

 

i had exactly the same problem. Tiny Ultra SA failed in signal generator mode and stopped at selftest 3.? I replaced U22? the single pole double throw switch.?? AS179-92LF? and that cured the problem.
Re: Using TinySA and NanoVNA in RF

 

On Mon, Feb 17, 2025 at 12:28 PM, <svkirk@...> wrote:
when you set the SA to zero span, the SA's sweep time becomes the time base for your "oscilloscope".
The "'scope" bandwidth is limited by the RBW and VBW filters, set them as wide as possible.
Best regards, Don Brant
Re: What to do when a selftest fails

 

On Tue, Feb 18, 2025 at 12:14 AM, Reg Du Toit wrote:
I bought my SA ultra from Zeenko Aliexpress
It was fine and passed all tests and calibration then
I have only used it as a signal generator and did not upgrade (v1.4 156)
While testing a transceiver I noticed the output level from the SA ultra was low so this is what I've done
Did a self test and it fails on #3 and goes no further
?
Tests 3 checks the 30 MHz CAL OUTPUT signal level.? If it is failing, try the following troubleshooting steps:
?
1.? Connect the CAL OUTPUT (top connector) to the RF INPUT (bottom connector).
2.? Select MODE:Calibration Output:30MHz
3.? Select Spectrum Analyzer
4.? You should see comb lines with the main carrier at 30 MHz @ ~-35.6 dBm.
5.? If you don't see any comb lines or comb lines with a carrier at 30 MHz well below -35.6 dBm then you either have a defective attenuator (U38:PE4312C-Z) or RF input switch (U22:AS179-92LF).
6.? Select LEVEL:LNA
7.? If you now see comb lines with the main carrier at 30 MHz @ ~-35.6 dBm then the RF input switch is working, and you have a defective attenuator.? Selecting LNA switches out the attenuator and switches in the low noise amplifier.
?
When the tinySA Ultra is used as a signal generator it is subject to reverse voltage or turn on/turn off transients from the device it is connected to.? The only reverse voltage protection the tinySA Ultra has is its ESD protection diode.? That diode is not meant for overload protection.??
?
I learned my lesson on a $5000 RF generator.? Thankfully the tinySA doesn't cost nearly as much.
?
Herb
?
Re: What to do when a selftest fails

 

Good day
I bought my SA ultra from Zeenko Aliexpress
It was fine and passed all tests and calibration then
I have only used it as a signal generator and did not upgrade (v1.4 156)
While testing a transceiver I noticed the output level from the SA ultra was low so this is what I've done
Did a self test and it fails on #3 and goes no further
Upgraded to v1.4 196
Checked cal output level on the SA ultra and its level is -72dBm, on scope unterminated is 20mV and terminated is 10mV
Inputted a 30MHz sine at 200mV and the SA ultra shows -50dBm
I will be very grateful if someone can please give me some advise and help fix my SA ultra
Many thanks, regards, Reggie
Re: Using TinySA and NanoVNA in RF

 

The high output can give a "start of sweep" pulse so no need to modify the HW
--
Designer of the tinySA
For more info go to

Re: Using TinySA and NanoVNA in RF

 

I just found this interesting using the Tiny SA as a sweep generator.?
Good luck?
?
Re: Using TinySA and NanoVNA in RF

 

Hi folks,
?
I haven't read through this thread in detail - just skimmed it quickly.? Thought I'd mention that a spectrum analyzer set to zero span can be used as a makeshift oscilloscope.? I don't recall if the TinySA has a zero span.? I haven't had to use mine in awhile.? I think it does, though.?
?
Anyway, I'm sure others can offer more advice on the topic.? I just thought I'd mention it in case it helps.
?
Basically, when you set the SA to zero span, the SA's sweep time becomes the time base for your "oscilloscope".? In other words, suppose your sweep time is 10 ms, and there are 10 horizontal divisions on screen, then your oscilloscope time base is 1 ms/div.??
?
Thanks,
?
Steve
Re: TiySA ULTRA APP for sweeping during hours/days with CSV exports #features #software #tinysa #ultra #WindowsAPP

 

QtTinySA from v1.0.2 can continuously save sweep data to (multiple) CSV files
??
?
Ian
Locked Re: Attenuation for Ultra

 

Hi Andy,
Fair enough. I also tested a Baofeng, Quansheng & VX7R. The results were similar to yours. I don't think the Baofeng radios have much or any filtering, whereas the Quangsheng (UVK6) and VX7R do. On another forum some talk about using the UVK6 at 30Mhz?and around 1Ghz. Using the tinySA I only measured in the mW region & sensitivity was crap as well. You can approximate sensitivity with the tinySA using a modulated tone and backing off the level to the point it just disappears into the noise then add 12dB.?

Dave??

On Sun, 16 Feb 2025 at 20:20, Andy G0FTD via <punkbiscuit=googlemail.com@groups.io> wrote:
On Sat, Feb 15, 2025 at 11:18 PM, VK3DPM Dave wrote:
I like your test and description, however I suggest at least a 10W 1st attenuator, should have at least double the power capability as attenuators can get hot and their resistance / attenuation can also change.
Agreed. But for the sake of completeness I was actually using a 10w 1st attenuator, not a 5w
as I previously stated (my typo). Actually the 10w version looks like the 5w version but just
with an added heatsink shimmed on to it ;-)
?
The 10w 1st attenuator is actually raised a few degrees too.
?
I also note with your baofeng test that you measure -31.6dBm if you add the 70dB of attenuation means the input power to the 1st attenuator is 38.4dBm which is around 6.9W. Something isn't right, I doubt a 5W handheld puts out nearly?7W, mine certainly doesn't. If everything is correct then your first attenuator is being overloaded which is not good.
?
The plots were a simple *average* of four sample, no max hold.
I just held the PTT until the plot was stable "enough" for a quick
check. That probably accounts for the approx 1.5db variation.
?
Just for fun I did do a quick check of my Yaesu VX7R using slightly
tweaked Tiny SA Ultra params.
?
That rig was cleaner, worst sprog was down at the -65db level.
But then again it did cost about 15x as much ;-))
?
73 de Andy
?
Re: TiySA ULTRA APP for sweeping during hours/days with CSV exports #features #software #tinysa #ultra #WindowsAPP

 

Hi to all,
?
I decided to put a description and example results of the current status of my APP in on shared folder (anyone with a link below could explore its status).
==> I don't want to generate new group messages on the status of this APP
==> please mark this message/ topic with "Ignore" if you don't like its subject (without posting your negative attitude)
==> if interested in this subject, you are free to explore monthly updates in the shared folder link
?
My goals with this message/topic are:
1. to show that TinySA is capable of some things like tracing a wider range of freq span and that it can have APP which can run "during hours/days with CSV exports"
2. to encourage others to improve & create a better TinySA APP (than my "work in progress")
3. please send me a direct message if interested in this kind of APP (not to spam other members of group) / if messages are "negative attitude without arguments or any usable idea", I will ignore them.
?
I am doing detailed testing of APP with some group members but it takes time for that task. I will share this APP when I think it is ready for sharing (to avoid spam messages like "No good. No good." ).
?
shared link with the current description and some measurement examples are located at the following link:
?
?
?
br,
ToniZG
?
tinySA App #Feature Request #Feature

 

tinySA App does not display the RBW or attenuation when they are set to AUTO; perhaps they could be displayed on the status bar along the bottom.?
I also do not see a control nor display for VBW.??
Having all 3 displayed on screen shots would be valuable for documentation purposes, VBW control/display would be more "nice to have" as most leave it untouched.
Thanks and best regards, Don Brant
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