NavList:

Frank I was tempted to reply to your comments about AM radio but it would have been a long, probably off topic, reply. Instead I will talk about time signals which gives an opportunity to  talk about early wireless while remaining more or less on topic.

Daventry calling.....Daventry calling....

Nicholls's Concise for 1930  states

"GMT is transmitted by wireless telegraphy from several high power stations. Daventry W/T Station transmits GMT time signals at 1030,1600, 1815 and 2200 on week days, and at 1030,1600, 2100 and 2200 on Sundays." Note that in that era Saturday was a weekday. Why the change on Sunday? My original guess was that  it was so that staff at Daventry and the time service could attend church. But then I thought that it was so a church service could be broadcast. I hoped to find a copy of the Radio Times giving Daventry's programmes but was unsuccessful. However I found a copy of the Indian Listener for 1936.

Indian Listener Link

This listed BBC Empire Service programmes as well as local programmes. On Sunday 9th August 1936 at 1225pm listeners could have heard Bells and an Empire service from St Pauls.   Indian Standard time is GMT + 5 1/2 so GMT would have been 1855. Greenwhich Time Signals could be heard at 6 15 am,  9 15am,  630 pm,  930 pm, 1130pm and 3 30 am  do not know if these signals were the pips or the chronometer rating signal. .This does not prove anything but is interesting as it is the pre-internet era. I

The problem with the church service theory is that it assumes that the time signals (w/t) were broadcast on the same tranmitter as voice. The US Department of Commerce  Radio Service Bulletin page 12  states that  at Daventry the time signals sometimes crashed the programmes so that was apparantly not an issue.

https://docs.fcc.gov/public/attachments/DOC-338340A1.pdf

Information about Daventry can be found at

https://www.bbceng.info/Books/dx-world/dx-calling-the-world-2008a.pdf

I believe that in its heyday Daventry had about 30 masts. The Empire service masts tfor Austalia and NZ were directional. They could be modified to rotate the signal 180 degrees. This sent the signal the other way around the earth. If that was ever done I do not know.

I have discoverd that in 1929 NZ broadcast time signals on 600m - 500 kc/s, the distress frequency.