During the course of analysing both single-dish and very long baseline interferometry (VLBI) data obtained from the Korean VLBI Network (KVN), we found a systematic oset between ux density measurements from dierent antennas. We were able to attribute a majority of the systematic osets to changes in the \a priori" antenna gains, which were found to have varied up to 10 percent at 22 GHz and up to 30 percent at 43 GHz. Using historical calibrator observations, we present a revised set of gains that may be applied to KVN data taken from 2015 August to 2019 January. Application of the revised gains to the KVN results in a consistency of correlated ux density measurements between the three baselines of approximately ve percent. We found that images from the recalibrated data typically have a 50 percent higher dynamic range, with some cases showing an increase of dynamic range of up to a factor of three.

ABSTRACT
1. INTRODUCTION
2. REDETERMINING KVN APERTURE EFFICIENCIES
3. EFFECT OF REVISED APERTURE EFFICIENCIES
4. ADDITIONAL ISSUES
5. SUMMARY
ACKNOWLEDGMENTS
REFERENCES

• Whee Yeon Cheong(University of Science and Technology,Korea Astronomy and Space Science Institute) Corresponding author
• Sang-Hyun Kim(University of Science and Technology,Korea Astronomy and Space Science Institute)
• Sang-Sung Lee(University of Science and Technology,Korea Astronomy and Space Science Institute)
• Do-Young Byun(University of Science and Technology,Korea Astronomy and Space Science Institute)
• Taehyun Jung(Korea Astronomy and Space Science Institute)