United Kingdom

“Essential engineering affecting MW Radio 5 Live [Brookmans Park] service in London and the South East 01 June 2020.
Essential engineering work is taking place on the Brookmans Park transmitter that will have periods of reduced power between 10.00 – 16.00 from 3rd June until 24th July.
Listeners’ access to Radio 5 live may be affected during this time period.
You can use our Transmitter Checker which will give you an exact view of the current status of the transmitter and any recent changes. We would recommend not re-tuning your Radio’s during this period of essential engineering.”
https://www.bbc.co.uk/reception/work-warning/engineering-works/essential-engineering-affecting-mw-radio-5-live-service-in-london
The site is home to
909 kHz BBC Radio 5 Live
1089 kHz talkSPORT
1215 kHz Absolute Radio
1458 kHz Lyca Radio
So reception of all these stations should have been affected.
Dr. Hansjoerg Biener (2020-07-26)

Australia

Townsville (Brandon), Qld – ABC Nth Qld Mast Replacement 630kHz.
Reading the below it seams that a standby low power mast might be in use throughout the period of main mast replacement on 630kHz with the addition of the 3 temporary FM transmission sites/frequencies.
https://www.abc.net.au/radio/northqld/important-signal-information/12443928
https://help.abc.net.au/hc/en-us/articles/360001603695-What-is-happening-with-the-630-AM-ABC-North-Queensland-service-
Ian (AUS) in mwmasts groups.io (2020-07-17)

United States

WTZA AM 1010 kHz Atlanta, GA USA on at high power at night.
Recently WTZA AM 1010 kHz in Atlanta, Georgia USA signed on simulcasting the Radio Punjab network. It is normally a 50 kW AM station during the day. However, the station is failing to drop down to its 78 watts at night. It is staying at its 50 kW daytime power (or maybe the critical hours power of 45 kW) throughout the night.
The station should be easy to receive at least in the southeast U.S. I was able to verify this on KiwiSDRs located in NC and Key West, FL.
Confusingly, the station broadcasts a station ID at the top of the hour as KTXV AM 890 in Dallas, TX. The ID is in English. Apparently, relaying an online feed from this Rado Punjab affiliate. No local station ID has been heard since it signed on with this format in late May. Radio Punjab broadcasts in the Punjabi and other south Asian languages with some commercials in English.
Harry S. Atlanta, Georgia USA in WOR Groups.io (2020-06-15)

Turkmenistan

Probably the only remaining AM transmitter in the country on 279 kHz has been operating very irregularly and even then with hardly any modulation.
WRTHmonitor June 2020 updates (2020-07-09)

Luxembourg

Re. rumours about RTL 234 kHz (2020-06-04) Rémy Friess has responded at longwaveradiolistening@groups.io:
“These rumours have been going on since Europe1 closed its longwave transmitter. But the station has never confirmed any of these.
However the station seems to go on reduced power every evening. This has been going on for months. At 1820 UTC (1920 UTC in the winter) ±2 minutes there is a break in transmission of about 5 seconds. Then the signal comes back with lower power.”
Mike Terry to WOR groups.io (2020-07-09)

United States

640 WNNZ Westfield MA
Does anyone who follows MW broadcasting know if this station has reduced its daytime power or changed its antenna pattern. I used to pick up this 50kW NPR affiliated daytimer with ease here during daylight hours in the Albany NY area. Now I find it’s almost impossible to hear.
Thanks.
John Figliozzi to WOR Groups.io (2020-06-18)

Ireland

Re. item of June 14th Spirit Radio 549KHz. The Harris DX25U transmitter damaged on the 10th of June in a lightning storm has returned to full service today Tuesday the 16th of June 2020 at 18:00 local time.
Spirit Radio lost the 549KHz AM service on the 10th of June 2020 at 11:50 local time, a reduced power service was restored on the 12th of June 16:00 local time.
Peter Leach (2020-06-16)

Canada

(CRTC) More ethnic programming requested for CJLV 1570 Laval.
Radio Humsafar Incorporated has applied to increase the allowable amount of ethnic programming on CJLV 1570 Laval from 25% to 40% during the broadcast week. 60% of the total programming will remain French, while the remaining 40% will cater to 12 ethnic groups in 4 different languages. The applicant states that the changes are necessary to remain financially viable.
Canadian Radio News FB group (2020-06-16)