[time-nuts] Leakage, tinySA

[Hal Murray]

My tinySA arrived a  few days ago.  I'm happy.

It comes in a nice box with an antenna that extends to a foot, a USB charging 
cable (mini, not micro) and a couple of cables.

It doesn't come with a manual.  I haven't found a manual online.  Their web 
site is pretty good, but sometimes I like a document organized to be read by 
turning pages rather than following links.

The minimum receive bandwidth is 3.1 kHz.

The specs say the lower frequency limit is 100 kHz but the UI doesn't enforce 
that.

My strongest signal is at 30 MHz.  It's -60 to -80 dBm as I wave it around.  
At 100 kHz bandwidth, the noise floor is -110 dBm.  The 30 MHz blip is clean 
enough to see the shape of the receive bandwidth filter.  (I'm assuming  the 
raw signal is much narrower than 3 kHz.)

I haven't figured out where it is coming from.  At first, I thought it was 
coming from low power do-it-yourself PCs.
  https://www.mini-box.com/
If I get near them, lots of spurs near 30 MHz come up out of the noise.  But 
powering them off doesn't change the 30 MHz.

The 30 MHz is clean.  I'm guessing it's the 3rd harmonic of 10 MHz.  I only 
have a few of them, but I don't like turning them off.  Or maybe the 2nd 
harmonic from the Lucent boxes.  ??

The 10 MHz is stronger near coax carrying 10 MHz and next to a Z3801A.  I'll 
have to try some good cables.  Anybody have a favorite source?  Is there a 
magic word?  Do I have to specify the type of coax?

I have lots of Gigabit Ethernet.  I have a blob at 125 MHz, and spurs at 120 
MHz and 130 MHz.  120 has a little brother 18 kHz higher.

The normal power up mode scans 0 to 350 MHz with enough attenuation so that 
most of my signals are lost in the noise.  Sometimes it comes up without the 
attenuation.  Then I can see all sorts of stuff.  The biggest ones are at 240 
and 288 MHz.

I think there is a mode for overlaying displays.  I haven't investigated.


Their web page has links to software to talk to it over the USB cable.  I 
haven't investigated.  Plugging in the USB cable adds lots of cruft.  The 
software would be unusable unless you are looking at a strong signal or at 
something in a hole that the cruft misses.  It might work if you can freeze 
the display, then plug in the USB cable to capture it.



-- 
These are my opinions.  I hate spam.