Telsat do you mean the distance between the bow and the mesh grill behind, its 4 1/4" ? Let me know if you need any more measurements.
Small update on the dual install.
Had to go to my niece birthay party by 1pm and started the install by 11:15am.
Got all the tools ready on my deck and dragged up the two antenna on the roof with a 5' extension pole from home depot with a 1.0"ID and a coupler after making several trips up and down the ladder by myself.
Tested the signal with my current setup and then removed the antenna and installed a single 4221. I seem to get the same signal as the 4228.
Nbc came in a little stronger pointing at the same position as I was before, guess from the wider coverage.
Then damm the coupler was too small the pipe on my existing tripod mount seems to be just a tiny bit bigger than 1 1/4" so I could not mount the other antenna on top.
But I did manage to moved the first 4221 all the way down the pole enough to get the lower part of the second antenna on the pole together.
Nbc and Fox both came in stronger but as soon as I installed back the pre amp the signal went down and lost some channels ?
Does the splitter that I used to combine the signals need to have a pass through ?
I did not have any more time to test and play around so I installed back my 4228. I had my 11 year old son in the bedroom checking the signal while I was on the roof with my cell.
I will try and go to home depot tomorrow and see if there is a coupler to connect the pole I bought to what I have. I having family over for dinner so not sure if I have time to play around with the antenna.
Finally installed the ground wire on the lower part of the mass, and its been through several thunder storms.
The coax line was always grounded with a block and used a copper rod.