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You can also try increasing the TinySA Ultra output to -22 dBM versus the -48.1 dBm level you showed in your setup (but that might still not be high enough for your needs). ?-22 dBm is the largest output signal you can generate at 50 KHz on the TinySA Ultra.

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Don

Using the HP209A S-meter was top scale and the voltmeter measuring 1,41 volts too; and no movement when tweaking the coils. I will try to reduce the output level of the HP209A with a toggle attenuator.

Was the S meter and external voltmeter stuck at the same positions when using the TinySA Ultra? ?If not then you need to reduce the output level of the HP209A until they are no longer “stuck”.

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I also just tested my TinySA Ultra into a 50 ohm load at 50 KHz and I measured -21 dBm when the TinySA Ultra was set to -22 dBm output so the TinySA Ultra signal generator output appears to work well at 50 KHz.

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Don

Yes, I know that. But there is no deflection in the S-meter , is stuck, no movement at all. And the external voltmeter is also stuck in 1,41v; of course I tweak the indicated coils.

I just looked in the manual again and it just tells you to adjust the signal level amplitude of the signal generator to a level that just gives you slight AVC deflection. ?Therefore you need to make sure you adjust the signal generator level appropriately (not too much and not too little).

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Bottom line for this TinySA Ultra discussion is that your TinySA Ultra is working correctly.

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Good Luck.

Don

Maybe this could happen or the signal too small or large. Do not know the right signal, do say nothing in the manual, in the first stage I can hear the tone and can? zero beat it.

As Jeff mentioned it sure sounds like the output level of your HP209A was set too high, whereas you saw nothing when you used the TinySA Ultra. ?I did a Quick Look in the manual you attached and see no mention on what signal level you should be injecting with the signal generator (but maybe I just missed that information) so it’s very possible you injected too small of a signal with the TinySA Ultra, and too large of a signal with the HP208A.

What signal level do you think you need to inject for your test, this is important information.

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Don

Hello,

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When the generator is on ; I have moved the sine wave potentiometer but not results Should I place an attenuator then? How do I know the right value output?

What a coincidence! Yesterday evening I took borrowed an HP 209A and made a try , this time the S-meter goes to the end of scale but can be made nothing ; I tweaked the coils but no a significant movement.

Yes, I use a DC blocker with the TinySA.

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I am thinking in selling the Drakes I am not willing to buy more measurement instruments, multimeters , signals generator, frequencymeter, probes....? and no get any results.

Dual output DDS function generators with better than 1 Hz resolution, 50 ohm output, ?and frequency coverage from 0 Hz to 15 MHz are readily available on Amazon.com from between $100 and $130 USD as an example. ?I purchased two of them (0 Hz to 25 MHz versions) when they cost about $60 USD each and they work great (one of the best purchases I’ve ever made).

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Just FYI,

Don

A high pass filter will clean it up. I have a whole assortment of them that I use between 1GHz and 14GHz. They can be found for less then 10 USD each at times on the auction sites.

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John

Hello Enrique,

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I just tested my TinySA Ultra using the same signal generator output settings that you are using and it appears to provide the correct approximate signal level when tested into an open circuit condition (high impedance condition).

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In my test setup I ran the output of the TinySA Ultra to my oscilloscope using a x1 probe so the TinySA 50 ohm output was looking into a relatively high impedance load (let's say open circuit).? Assuming the load was really 50 ohms versus the open circuit condition then my oscilloscope readings would be half of what it really measured.? You will see that I measured 2.31 mV RMS into an open circuit load so if the load was really 50 ohms I would have measured 2.31mV/2 = 1.155 mV.? Then if I calculate the power into a 50 ohm load it would be ((1.155 mV)*(1.155 mV))/50 ohms = 0.0267uW which equals -45.7 dBm which is pretty close to the -48.1 dBm output setting.? The signal level is so low that the 2.31 mV RMS measurement using my oscilloscope is just an approximate value as is the "open circuit" condition I assumed.? I don't see anything unusual, and the TinySA Ultra was indeed generating a signal at 50 KHz as shown in my attached picture.

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P.S. make sure you are using capacitive coupling (DC block, etc.) between the output of the TinySA Ultra and your test circuit (or make sure the test circuit DC voltage is near zero) so you don't feed excessive DC voltage back into the output of the TinySA Ultra.

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Just FYI,

Don?

I want to report back. I've got a low pass filter (f_c=6 GHz) and the 8 GHz signal was still there - so it is indeed a mirror as Erik suggested.

If i take a closer look, it seems to be a mirror of the 2 GHz wideband LTE signal. Case closed! Thanks for the help.

Thanks!!

The cables that come with the tinySA Ultra have about 0.5 dB loss at 5 Ghz and 0.25 dB loss at 2.5 GHz

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Designer of the tinySA
For more info go to

Specifically interested in 2.4GHz wifi range and 5GHz UNII 1, 2A, 2C, and 3 range. I know my measurements won't be anything to take to the bank on the TinySA in Ultra mode, but was hoping to get a ballpark idea of channel power in some configurations. This looked like a good option outside of spending 13k+ on a Keysight MXA haha.

Are there any available spec sheets for the kit SMA cables? Hoping to find a table or chart of insertion losses in dB.