It was a surprise in this Dec / January 2019 when measured the IBB BBG Udorn
Thani eastern Thailand relay fq channels, someone of the Thai technicians
had started an action and UDO frequencies were aligned nearly to x.000 even
accurate, after some odd fq difference of mostly minus 60-90 Hertz ore more
traced on this Udorn Thani site, in past decade or so.

Now most used fq of these high power bcast centers are accurate x.000, like
Encompass Digital Media Services, replacing Babcock, at
Woofferton England, Oman{BBC and R Oman}, Singapore, Ascension Island.
IBB BBG Lampertheim, Kuwait al-Dschahra suburb, Udorn Thani Thailand,
{but not Greenville, Botswana, nor STP ... }
Radiotelecentr (PRTC) transmitter Grigoriopol Maiac.
MWV New Life Station, Mahajanga, MDG, Madagascar.
Tajik Radio site Orzu TJK.
RRTM RED Telecom Tashkent Uzbekistan bcast center
CJSC Yerevan Gavar
Vatican Radio Santa Maria di Galeria, Vatican State
TDF Issoudun France,
Japan Yamata site,
Romania RadioCom RRI Galbeni, Tighanesti, and Saftica too.
Sudan Radio Omdurman.
CRI Albania Cerrik Europe relay always excellent eoperation.
Also some 95% of the China mainland transmitters are accurate even fq these 
days.