There is nothing apparent about the distance shift
The earth spins about its axis (1662 km/h at equator), the earth spins about the sun (108,000 km/h), the sun and earth spins about the galaxy centre (72,000 km/h).
DRAW the path that's a lot of movements .. this bit you seem to get part of but not all.
For example at the poles the earth spin about it's axis is almost 0 km/hr if your imagine 1 meter out from the orbital pole it covers the 6.28m circle in 24 hrs versus the 12800 km the equator must travel in that time.
We often simplify classic problems and say there is no relative motion but when you are trying to test what you are you can't have that simplification.
You are launching a beam of light which is an electro-magnetic wave it is exactly the same as a radio transmission from a jet fighter pulling a complicated turn in a 3D space sense.
Surely you see there is nothing different here ... if there is please explain what is different.
I assure you we understand the problem ... you haven't got a clue which is obvious.
A few days ago some clever scientists used all the atomic clocks around the world to map the shape of the earth because an atomic clock can measure the force of gravity and that is it's height from the centre of mass of the earth to 30cm
http://phys.org/news/2013-10-height-clocks.html
You will note the reason they did all of that
For that purpose, our colleagues in Australia do not want to compare frequencies over 2000 km, but over approximately 4000 km which is, of course, making things even more complicate.
They are trying to get a baseline of the frequency shift of two points on earth 4000km apart so they can do tests sort of along the lines of yours but even more interesting.
So 30 cm is easily measurable ... so your challenge is to get your tube perfectly flat to all the spins or you will get a frequency shift of the different speeds of launch to receive position and hence it will doppler. That doppler will be refracted thru the different media ..
DO YOU UNDERTSAND WHAT REFRACTION IS AND WILL DO????
IF YOU DON'T UNDERSTAND IT WIKIPEDIA IT AND IT WILL GIVE YOU THE ANSWER
When a ray of light is incident on any surface, it gets refracted, transmitted and reflected. So some of the incident ray's energy is lost in transmission and reflection. So a refracted ray is less bright than the incident ray because it has lost energy.
So contrary to your claim refraction will change the brightness and you have to stop it or at the very least control it to a known.
So if you want to do brightness tests your setup experiment will need to stop the refraction by (a) having no media changes or (b) you need to stop the frequency changes which means stop the earth from moving ... choose a or b
I will say your 15% seems very high to me so I suspect there is another problem with your setup which we haven't yet identified perhaps air in the tube or some such thing.
Your electrical wire test is ridiculous you don't understand how electricity works if you believe that garbage as you wont measure a difference.
I will give you a better electrical analogy take you water hose out lay it out for 10 meters with the spin of earths direction do you really think you will be able to measure a difference of flow between an alignment of earth and against it .... you are a lunatic if you think you can the resistance against the walls of the hose will exceed any difference.
Even in a gold wire and at absolute zero the effect will be lost and you will measure nothing. You can measure coriolis effect on some things but not that.
This stuff is not hard
