This one is a little obvious after some thought, but I haven't heard it
mentioned before.

The frequency of light is like a clock in itself - if the frequency is lower
then the clock at the source is slower as measured by an observer who also
measures that redshift. If the redshifted electromagnetic radiation was a
radio carrier wave then the frequency the observer must tune to is further
down the dial, as expected, but the sounds transmitted via that carrier wave
will also appear to be slowed down, like an audio tape running at the wrong
speed.

This is true regardless of the cause of redshift - source moving away from
observer, source near a gravitating body, or source at a very great distance
(Hubble shift).

The Hubble redshift observed on Earth must also be accompanied by time
dilation. If the frequency of light received is half, for instance, then
the clock at the emitting end of that electromagnetic transmission is
running at half the pace as the clock at the receiving end.

I assume that this time dilation is taken into consideration when observing
pulsed transmission of the rotation of galaxies (pulses will be measured as
slower than the actual rate, galaxies will appear to rotate slower then than
actually do etc.)

Anyone know more on this?

--
Kind Regards
Robert Karl Stonjek