For Progress and Soyuz spacecraft the PKhO comes from RKTs-Progress, who also produce the Soyuz rocket and fairing too. (So confusing having satellites and factories and rockets all with the same name!) Same also for Resurs-P, Bars-M, Lotos-S, Pion-NKS. Note that an SZB is ordered for these satellites,http://forum.nasaspaceflight.com/index.php?topic=17286.msg1500874#msg1500874Lavochkin produce the Fregat upper stage, and it comes with a PKhO. They also produce the narrower fairings used with the Fregat.https://forum.nasaspaceflight.com/index.php?topic=15064.msg1394949#msg1394949The 81КС is the large ST-type fairing which is based on article 14С738, the Persona fairing. It is used with the Fregat and is produced by RKTs-Progress.http://forum.nasaspaceflight.com/index.php?topic=17286.msg1500874#msg1500874Now to launch Resurs-P № 2 on a Soyuz, it was decided to use the larger 81КС fairing. As that launch did not require a Fregat, which would have come with a PKhO, RKTs-Progress supplied one instead. It was referred to as 196КС.http://www.samaratoday.ru/img/2014/12/KA-Resurs-P-2.jpghttp://forum.nasaspaceflight.com/index.php?topic=24942.msg1502258#msg1502258
This picture was took at TsSKB-Progress on 18th december 2008 by ESA photographer Stéphane Corvaja.It shows Bloc I of rocket n°76029169. I don't know for which launch it was used.
What are missing are images of the PxO for Obzor and similar sized satellites launched on Soyuz.
Is there any evidence that a specific PxO is always used in conjunction with a specific payload fairing?And is the Bars-M payload fairing truly unique, or has it been used on earlier launches?
Progress MS-02 PxO (from Energia.ru)