[Elecraft] Gurus

Wes wes_n7ws at triconet.org
Thu Jun 10 15:24:53 EDT 2021


Dean's making the case I thought to make.  Couldn't agree more.

Dave said: "Here is an interesting video showing both the strengths, and 
weaknesses of the tinySA.

I looked at the videos and said, "Okay, where are the strengths?"

I spent a lot of years sitting in front of spectrum analyzers. One of the first 
things you want to do after
displaying signals of interest is to adjust the input attenuator up or down. If 
you add or remove10 dB of attenuation
and ALL of the signals do not change by exactly 10 dB, you have a linearity 
problem at that setting.  Don't use it, or
if you do, understand that you are getting bogus answers.

Likewise, if you have a really clean, stable source like a quality OCXO with 
published phase noise specs and you
measure it with your SA and it looks other than that, you're measuring your SA's 
shortcomings.  That's okay as
long as you understand them.

Wes  N7WS



On 6/10/2021 10:58 AM, Dean L wrote:
> After watching the video of the TinySA next to the HP8921, I can't see how
> you could EVER trust the results of the toy.
> I watched as OM in the video was scratching his head wondering where the
> artifacts on the display of the TinySA came from.
> Did I watch the wrong video? If I didn't see the image captured by the HP,
> I would have comd to different conclusions.
>
>
>
>
> I was not impressed:
> Same author different video,
>
> https://youtu.be/uwXUZSdxNq4
>
>   As he changed the amplitude the harmonics generated by the TinySA changed
> accordingly making the signal look "dirty"
> Great tool if you have a $10k Service monitor sitting right next to it...
>
> I understand it's $100 gizmo, but might confuse an unsuspecting operator.
>
>
> I would not fault my kilobuck HF rig with this unit
> YMMV
>
> 73
> Dean K2WW
>
> On Thu, Jun 10, 2021, 10:23 Dave <dave at nk7z.net> wrote:
>
>> Interestingly enough I don't see that issue here with my K3, and tinySA.
>>    I also don't use the built in antenna.  I use a tap and attenuator
>> combination.
>>
>> I am also using a non clone device, as opposed to a clone device.  Some
>> clones don't have the internal shielding.
>>
>> Here is a compare to a clone vs a non clone:
>> https://www.youtube.com/watch?v=I5IzLAGgKg0
>>
>> Here is an interesting video showing both the strengths, and weaknesses
>> of the tinySA.  A compare of the tinySA to an HP 8921A SA:
>> https://www.youtube.com/watch?v=xFtF2AYT0iQ
>>
>> For the price, and if one is careful, and aware of how to use the
>> tinySA, you can gain a lot of knowledge for around 100 bucks.
>>
>> I am half tempted to buy one, and add a tap to my output coax, add
>> power, bring it to a very low input level, and just keep the tinySA on
>> all the time I operate, as an alarm that I might have an issue.
>>
>> 73, and thanks,
>> Dave (NK7Z)
>> https://www.nk7z.net
>> ARRL Volunteer Examiner
>> ARRL Technical Specialist, RFI
>> ARRL Asst. Director, NW Division, Technical Resources



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