[Mesorah] Vowels under YKVK

[Richard Wolpoe via Mesorah]

Correction HAL ADNY or HAL ADOshem

Sent from my BlackBerry 10 smartphone.
  Original Message  
From: Richard Wolpoe
Sent: Monday, October 10, 2016 13:55
To: mesorah at aishdas.org
Subject: Vowels under YKVK


I was chatting about Ha'azinu's HaLAdY and its Vowels

OK 
When YKVK is Read ADNY the first letter takes a Sheva
This "seem"s to represent the HATAF patach for ADNY

Yet when it is pronounced Elokim
The Yud gets a HATAF segol and not just a "sheva"

EG See Tehillim 140:8 Elokim (YKVK) ADNY

Why isn't the vowel under the Yud consistently with or without a hataf?