Good afternoon all,

Just received my NanoVNA V2 Plus4 from the HCXQS Group Tindie store.  I've been following the manual written by Bill, NC4BR and so far, I am really amazed at all the features this unit has.  This unit is a ham radio tinkerer's delight!

I just finished making a PCB board with SMA connectors to go on the back of my unit to store the calibration standards, the female to female SMA connector, and the two test cables.  Hopefully, this way, I'll not loose the standards and will keep them always with the unit.

Thanks much and 73,
Ben, KD5BYB

Ben,
You might want to remove the center contacts from the "storage" connectors to reduce wear on the calibration standard pins.
--John Gord

On Thu, Sep 2, 2021 at 07:38 PM, Ben Hall wrote:

>
> Good afternoon all,
>
> Just received my NanoVNA V2 Plus4 from the HCXQS Group Tindie store.  I've
> been following the manual written by Bill, NC4BR and so far, I am really
> amazed at all the features this unit has.  This unit is a ham radio
> tinkerer's delight!
>
> I just finished making a PCB board with SMA connectors to go on the back
> of my unit to store the calibration standards, the female to female SMA
> connector, and the two test cables.  Hopefully, this way, I'll not loose
> the standards and will keep them always with the unit.
>
> Thanks much and 73,
> Ben, KD5BYB

On 9/2/2021 11:28 PM, John Gord via groups.io wrote:
> Ben, You might want to remove the center contacts from the "storage"
> connectors to reduce wear on the calibration standard pins.

That is a great idea! I'll make that change to my PCB storage board today. :)

thanks much,
ben

Yep.  SMAs have a relatively limited mate/demate cycle life rating (500).  Many nanoVNA users install and leave male-female adapters or pigtails on their nanoVNAs so that the nanoVNA's SMAs don't see all the mate/demate cycles of doing calibrations and attaching duts. The limited life applies to any SMA, including those the cal standards are built in to, so best to not needlessly mate/demate them.  John Gord's suggestion of removing the center contacts on the storage connectors is a good one, though why mate the calibrators at all when not in use.

At best have a small box with foam insert with the vna in it.. A bit of
storage room for cables and adaptors.. Maybe some a bit longer cables with n
connectors on other end and use n standards?? Or screw sma to n adaptors on
the unit and let them there??

The hint with male female is a good one... If worn out replace the extension

Greetz sigi dg9bfc



Am 03.09.2021 14:02 schrieb "Lou W7HV via groups.io"
<louandzip=yahoo.com@groups.io>:

> Yep. SMAs have a relatively limited mate/demate cycle life rating (500).
Many nanoVNA users install and leave male-female adapters or pigtails on their
nanoVNAs so that the nanoVNA's SMAs don't see all the mate/demate cycles of
doing calibrations and attaching duts. The limited life applies to any SMA,
including those the cal standards are built in to, so best to not needlessly
mate/demate them. John Gord's suggestion of removing the center contacts on
the storage connectors is a good one, though why mate the calibrators at all
when not in use.



_._,_._,_

* * *

I was fortunate enough to score a handful of push on SMA male connectors, which seem to have even more consistent results than torqued SMA. I suspect this is because of the custom spring fingers placed radially around the shield barrel. The only downside seems to be  these springs (which aren’t present on the regular SMA male) tend to wear the inner surface of the female side shielding barrel:

The plus side is that surface is easily accessible with an alcohol-saturated swab for quick and easy cleaning.

I believe they are Hasco brand, and it seems Hasco also has a load with the interface integrated, which seems like a no brainer if it performs:

https://www.hasco-inc.com/terminations/rf-load-sma-male-push-on-termination-dc-to-18-ghz-1-watt/

The adapters aren’t cheap but again, they are more consistent in my testing and makes calibration far easier/faster.

https://www.hasco-inc.com/adapters/sma-male-to-sma-female-push-on-adapter-dc-to-18-ghz/

I'd never heard of push-on SMA adapters - thanks for the info. Here are a cheaper version from Pasternack:
https://www.pasternack.com/sma-male-sma-female-straight-adapter-pe91336-p.aspx?utm_source=google&utm_medium=cpc&adpos=&scid=scplpP83854&sc_intid=P83854&gclid=Cj0KCQiAnuGNBhCPARIsACbnLzoIttCTHeOVYOfDj42Xo9KRAsvnk-3i7URuy1JJWIrdP1fYw_iCXIEaAg2dEALw_wcB

and cheaper yet from Amazon:
https://amzn.to/3GCzlSy

73,
John AE5X
https://ae5x.blogspot.com/

Супер калибровочный комплект!
10Evro!!!:)