#19467

On Sat, Feb 15, 2025 at 08:08 PM, Matthew Rapaport wrote:

70dB is good. I use 80. But why turn off the LNA? Not that you need it with a direct connection to the HT, but I don't think it hurts the SA to leave it on...

If it's not inline then it cant get screwed up with a high powered mistake.

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It's a first principle thing that I always carry in my mind.

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Besides, any active device can be "bent" or desroyed with abuse.

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If it aint needed the dont use it.

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You save on potential harm, you save on potential unwanted products ;-)

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If it aint in line then it does no harm ;-)

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Simples...

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73 de Andy

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Re: Attenuation for Ultra

#19466

70 dB of attenuation is a bit much for a 5-watt source.? 70 dB down from 5-watts is 0.0001 mW or -40 dBm.? 80 dB of attenuation is even a decade lower or 0.00001 mW or -50 dBm.? If you are measuring spurious or harmonic emissions, you're sure putting yourself at a large disadvantage.? 55 dB of attenuation is more like it which would yield -25 dBm.?

Don't just "throw" attenuation hap-hazardly at the situation.? Do your homework and apply attenuation accordingly!!

Dave - W?LEV

Virus-free.

Show quoted text

On Sat, Feb 15, 2025 at 8:08?PM Matthew Rapaport via <quineatal=[email protected]> wrote:

70dB is good. I use 80. But why turn off the LNA? Not that you need it with a direct connection to the HT, but I don't think it hurts the SA to leave it on...

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Dave - W?LEV

Re: Attenuation for Ultra

#19465

70dB is good. I use 80. But why turn off the LNA? Not that you need it with a direct connection to the HT, but I don't think it hurts the SA to leave it on...

Re: Attenuation for Ultra

#19464

Resent due to send error / no edit mode available.

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This question often gets asked.

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Here's my current test setup for measuring those ubiquitous 5w handheld rigs.

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At the antenna connector of the HT / walkie talkie I use a 5w rated 40db attenuator.

This is followed by a 2 watt rated 30db attenuator.

Both are available quite cheaply from the usual online suppliers.

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Note - good practice for newbies.

Remember that the highest power attenuator is the FIRST one to connect to a transmitter etc.

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In order to keep the input level to the Tiny SA? at? safe level I practice the following:

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1 - Turn off the Internal LNA.

2 - Connect the attenuators in the correct order. Highest power rated direct to the TX etc.

3 - For safe use of the Tiny SA products I like to use an input level of typically -25dbm or -30dbm.

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This not only ensures a level that does not induce potential spurious responses, but also

gives another level of input protection should I accidentally have the internal LNA switched on.

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In other words - if you got a 5w rig then you a safe way to use the Tiny SA is to use 70db

of attenuation without relying upon the internal attenuator. (Safer)

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4 - Using a typical sweep from say 140-1500Mhz and a wide RBW will allow you to

quickly sweep the band in a sensible time (using max hold function) whilst giving you

enough dynamic range for a basic go / no go result. For most ham radio stuff we

mostly interested in knowing if something is crap or not. So if we can see typically

some 50-60db below the carrier then we've got an answer.

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Good enough for ham radio purposes before the pedants crawl out like cockroaches.

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I've attached some screengrabs of an old Baofeng UV5R and a Quansheng UV5R Plus

(the latter is a different rig, don't confuse it with the Baofeng just becuse of the model

number!!).

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I'm NOT here to argue FCC crap, just reporting the results ok !

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Oh and just for some fun I set up my Yaesu VX7R on RX for the 2nd

harmonic of the 2m band and left it on by the window with a clear path

for a walking route, and had an audio recording device placed next to it.

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Then went for a walk with the Quansheng on 2m with it's stock rubber duck.

I made my first test transmission at 50 metres away, then approx 200m, then 500m.?

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The 2m band harmonic was never heard on the home receiver even at 50 yds.

No it's not an ISO9000 quality test but it does give us a reference to start with.

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[If you wanna debate this stuff then maybe another forum should be used]

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73 de Andy

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Re: Thanks for DFU-Buddy Software

#19462

It's amazing how well this Mac utility works...plug & play and makes updating NanoVNAs and tinySAs simple.

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73 - Dino KL?S

Re: Battery of my Tinysa Ultra expired & no new available ! Does "smart" power bank is compatible ?

#19461

Many thanks Erik !
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It is working in very excellent way ! I started to test it since you post your kind replay, but I did not write about it's success immediately preferring instead to test it continuously for enough time before writing about it's success !?
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Now I can say with trust that this power bank really suitable for our sensitive equipment without risk to damage them !
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Erik you really save me, because no any express logistic method accept to ship lithium ion batteries (as stand alone package) to my country even from AliExpress or Alibaba ......

Re: Using TinySA and NanoVNA in RF

#19459

From what I read in the service manual, all swept measurement are with RF in and measurement out at the same frequency. That's work that should be easy to do with a VNA as there is no frequency translation. Issue is perhaps the loading of the circuit. The VNA is 50 Ohm input. You can put a series resistor in series with the VNA input to increase the impedance. It depends on the circuit output impedance what is acceptable. Perhaps even add AC decoupling if needed. 1K series resistance attenuates the measured signal by 26.4dB but the passband shape should still be clearly visible.

All IF measurement seem to be done maximizing the S-meter reading. One measurement needs a frequency counter. That can be done with the scope as it's a digital one.

Although the VNA will generate a square wave, for this radio it should not matter.

I also saw an absolute measurement with at 100 dB input to adjust the S-meter. That's a huge level, depending what the unit is :-).

Re: Analog detector output in Zero span mode #feature_request

#19458

Many thanks for the quick reply - I am impressed!

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It will be more very valuable for me if AGC in Listing mode is disabled.
Want to use tinySA in connection with developing firmware for wireless radio systems.?
Here, it is very useful to have a good RF detector that shows whether a certain frequency is being transmitted.
I can hereby see when a tramsnitter is active together with e.g. SPI communication with radio chip.

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When can I expect a firmware update for tinySA with disabled or option to disable AGC in Listen mode?

Re: Analog detector output in Zero span mode #feature_request

#19457

There is indeed an AGC active in the firmware

This can easily be removed, or even be changed to user settable.

--

Designer of the tinySA
For more info go to

Re: Using TinySA and NanoVNA in RF

#19456

The VNA by itself should be suitable foe sweep alignment. But it is not plug and play. A method needs to be worked out that is safe for both the radio and the VNA and produces reaonable results.

On Fri, 14 Feb 2025 08:59:52 -0800
"Martin via groups.io" <martin_ehrenfried@...> wrote:

It is difficult to tell because part of the procedure is missing, and the resolution of the scanned page is not that good (Groups IO scales it).

At first glance, it looks like a voltage output, or some other trigger, from the swept oscillator time base, needs to be driving the scope X axis, to produce a frequency (X) vs amplitude (Y) display.

You should be able to achieve a similar function using a VNA to produce the swept signal, and the SA to see the resultant frequency response, without having to trigger one from the other. But you will have to be careful to set appropriate sweep times on each device.

You will probably have to use separate devices because the RF and IF frequencies will be different from each other, but if you are trying to measure the IF response, around the same centre frequency, then it should be possible to do that just using a VNA.

Regards,

Martin
-- 

73

-Jim
NU0C

Re: Using TinySA and NanoVNA in RF

#19455

Thank you martin, just uploaded the original PDF to the thread.

Re: Using TinySA and NanoVNA in RF

#19454

Manual uploaded, 9&10 circuit description, 11&12 alignment.

Yaesu FRG7 hi res manual.pdf

Thanks for DFU-Buddy Software

#19453

Thanks to chri5k for adding DFU-Buddy to the files section.? I wasted about 20 minutes trying to get my windows machine to recognize my TinySA.? Windows wouldn't even recognize the SA or let me install the DFuse drivers.? Then I remembered seeing DFU-Buddy I had seen when I was browsing the files section.? I grabbed my Mac and installed the software (you do have to go into system settings and give permission to install the software) and the rest was easy.? Opened the software, found my TinySA, selected the dfu file I had downloaded and installed the firmware.? Done and dusted in way less time than I had fought with the PC.

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Terry

Re: Analog detector output in Zero span mode #feature_request

#19452

Hi Erik

Thanks for reply regarding C85 - done :-)

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However, it does not work as expected :-(
There is a lot of noise and in some cases it seems like that an AGC increases the sensitivity when there is no signal.

Have made a test setup where the signal is generated by a signal generator with a 100% AM modulation.
The signal strength at tinaSA is approx. -46dBm
In parallel with tinaSA I have a simple diode detector.

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First test: Screen dump from tinaSA in Zero-span mode.
Here it is clearly seen that the signal changes between approx. -48dBm and < less than -100 dBm - as expected

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Second test - attached file: tinySA-ListenMode-50HzAM.pdf
Lots of noise on blue line (Listen signal from tinySA)

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Third test: - attached file: tinySA-ListenMode-1HzAM
Even more noise on blue line (Listen signal from tinySA)

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Have tried different settings of REF LEVEL, but it does not affect the signal on the Jack connector in Listen mode.

How to get more clean signal on Jack connector in Listen mode?

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Thanks in advance, Knud

tinySA-ZeroSpan-50Hz-AMmodulation.png

tinySA-ListenMode-50HzAM.pdf

tinySA-ListenMode-1HzAM.pdf

Re: Using TinySA and NanoVNA in RF

#19451

It is difficult to tell because part of the procedure is missing, and the resolution of the scanned page is not that good (Groups IO scales it).

?

At first glance, it looks like a voltage output, or some other trigger, from the swept oscillator time base, needs to be driving the scope X axis, to produce a frequency (X) vs amplitude (Y) display.

?

You should be able to achieve a similar function using a VNA to produce the swept signal, and the SA to see the resultant frequency response, without having to trigger one from the other. But you will have to be careful to set appropriate sweep times on each device.

?

You will probably have to use separate devices because the RF and IF frequencies will be different from each other, but if you are trying to measure the IF response, around the same centre frequency, then it should be possible to do that just using a VNA.

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Regards,

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Martin

Re: New FW release: Ext gating repaired

#19450

开云体育

Fine. Was this for TintSA app?

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Mike N2MS

Show quoted text

On 02/14/2025 9:31 AM EST Erik Kaashoek <erik@...> wrote:

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Please ignore.

Wrong group

--

Designer of the tinySA
For more info go to

Re: New FW release: Ext gating repaired

#19449

Please ignore.

Wrong group

--

Designer of the tinySA
For more info go to

Re: New FW release: Ext gating repaired

#19448

I wondered a few days ago about the other message, too.

What's this firmware for and where to find?

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Klaus, DL5KV

Re: New FW release: Ext gating repaired

#19447

Erik,

I don;t see this release under

 Index of /tinySA4/DFU

The latest is

tinySA4_v1.4-196-g1e9c187.bin

Mike N2MS

Show quoted text

On 02/14/2025 7:41 AM EST Erik Kaashoek <erik@...> wrote:


New FW release
Version V0.1340

Changes:
- External gating working again.

External gating can only be activated using: Counter 1 using input A with gating from input B or counter 2 using input B with gating from input A.
Not all illegal configurations are yet block (using counter 1 with A gated by B and then select counter 2 to use input A)
--
Designer of the tinySA
For more info go to 

Using TinySA and NanoVNA in RF

#19445

Good day All.

I'm trying to restore/align an old FRG7 Com-radio, have a TinySA that have been using as an RF sig gen and a Zeewiie DSO1151g scope that 'should' run past 100Mhz, well lets just say 30Mhz is about its limit, this means I'm unable to look at signals in RF range.

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My question, attached are sample alignment procedures for the RFG-7.

Given that I dont have a fit-for-purpose scope (have three scope probes) but do have a TinySA and a NanoVNA (on the way) how should I then perform the alignements that require use of a scope, so what modifications do I make to testing and how should I review the results.

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Scopes, Im happy with using. SA and VNA interpretation, I'm not familiar with and no option to buy a higher bandwidth scope.

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Thank you.

Br John.

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