Hello Erik,

> Is there any downside to fitting these capacitors, bearing in mind that they were omitted > from the unit??

Why were C13, C17 and C20 not populated to begin with? ?The cost could not have been that much? ?There are no drawbacks for adding? ?I see you suggested 33pf whereas walker used 22pf; any reason for the difference??

Thank you for your time, ? ? ? ? ?larry

开云体育

I'm guessing that the serial number is the date plus a number. 200912xx would be 12 Sept 20, 201004xx would be 4 Oct 20 etc. Only Erik can confirm. I found that replacing the unit back in the case was a bit of a fiddle but OK in the end. Perhaps the Chinese ladies who do the assembly have more nimble fingers than mine.

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On Wed, Nov 25, 2020 at 10:05 AM, geoff M0ORE wrote:

I checked my tinySa this afternoon after getting some 33pF caps from spares box and the caps were already fitted. H/W V0.3, serial number 20100409. Not checked value so I can only assume they are 33 puffs.

I wonder what the hardware rev # or serial number? was when they started installing these caps?

Roger

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I checked my tinySa this afternoon after getting some 33pF caps from spares box and the caps were already fitted. H/W V0.3, serial number 20100409. Not checked value so I can only assume they are 33 puffs.

No
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Hi Eric

Is there any downside to fitting these capacitors, bearing in mind that they were omitted from the unit??

Regards
Jeff

I have written a documentation for this specrum analyzer board:


73, Rudi DL5FA

@Scott

i just downloaded without any problem.
Nevertheless, i put it on my server:

http://www.siglishofen.de/Scott.rar

Banggood has two small 4.4GHz SA with screen at $69 and $89. It rather looks like their firmware has been adapted/rpped-off from the TinySA Github. I have ordered one of each and will report when they arrive from China (expected around Christmas).

On Wed, Nov 25, 2020 at 06:16 AM, Massimo Martini wrote:

Thank you for the screenshots Herb.

Can i use the nanoVNa signal generator attached directly to the tinySA input without attanuator?

? ? If the tinySA is in its normal auto settings mode, then it should adjust its internal attenuation automatically to prevent the output of the NanoVNA from over driving its input.? In manual mode, I would suggest setting the internal attenuation to 20dB.? No external attenuation is necessary.

? ?Beware that the above applies to the LOW INPUT.? The HIGH INPUT does not have the input attenuation and filtering that the LOW INPUT does so a external 20dB attenuator would be a wise choice when the NanoVNA is connected to it.? Without the attenuator the tinySA will not be harmed by the NanoVNA but a lot of spurious signals may be produced.

? - Herb?

? ?- Herb

Thank you for the screenshots Herb.

Can i use the nanoVNa signal generator attached directly to the tinySA input without attanuator?

On Wed, Nov 25, 2020 at 05:13 AM, Erik Kaashoek wrote:

If you have the capability I suggest to solder 33pF 0603 SMD capacitors on the open positions C13, C17 and C20. This will reduce the currently visible 48MHz harmonic spurs to almost zero.

Erik,
? I had some 22pF smd caps on hand, so with magnifying goggles and soldering iron in hand I installed the capacitors in the prepared positions. No awards for straight alignment of the installed capacitors, trying to tack solder one side in place so I could solder the other side was a bear.? Anyway, here are my results:

?Unmodified, LOW and HIGH Inputs-Open? ? ? ? ? ? ? ? ? ? ?22pf capacitors installed, LOW and HIGH Inputs-Open.??
?? ? ?

? ?So yes the 48MHz harmonic spurs are visibly reduced by the addition of the capacitors.? I also looked at the LOW INPUT with telescopic antenna attached before and after the modification:

?Unmodified, LOW Input-Antenna? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?22pf capacitors installed, LOW Input-Antenna.
?? ? ?

? ? ?The over the air signals swamp the 48MHz harmonic spur modifications.? If the tinySA is primarily used with the supplied telescopic antenna, then the addition of the decoupling capacitors is not going to be of much use.


?With the output of an RF generator (?-30dBm, 175MHz?) attached directly to the LOW INPUT,? no 48MHz related harmonics are visible with the 22pf capacitors installed (other visible signal is FM band related).
??

? ?

0603? capacitors 33pF

? Great foresight to add the pads for additional decoupling capacitors.

? - Herb

On Wed, Nov 25, 2020 at 04:22 AM, Scott wrote:

that soft wear?is no longer available .it dont?seem to to be any soft wear?for that spectrum analyzer . just my luck .lol.

? ?The price of the tinySA is a bargain, but when you add in Erik's technical, firmware and software support it really stands out.? My ham club purchased one of those 35M - 4.4GHz devices and it sits in a drawer somewhere from lack of use because of no support.? We would have been much better off spending the money on a second tinySA for dedicated use as a signal generator.

- Herb

I've seen only now your second reply

Ok for the 33pF capacitors, i will.

Thank you Erk!

Thank you!

i've got it at a bargain price and only after reading this group i suspected that it could be a copy. I thought that there were no fakes (yet) for the tinySA.

?

If you have the capability I suggest to solder 33pF 0603 SMD capacitors on the open positions C13, C17 and C20. This will reduce the currently visible 48MHz harmonic spurs to almost zero.
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Your OK!
Fully genuine
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Hi Erik,?

self test positive

here is the photo inside:?

there is nothing written on the pcb on the diplay side.

?

I left the FW upgrade as last step, not done yet.