03 April 2009

D-Star Simplex

Robert, KJ4HAL, asked a question while we were doing some D-Star Simplex on 146.520 the other night: Should we be using digital voice on 146.520? At first I thought sure, why not, but the question has dogged me for a few days. Tonight I did a Google search on D-Star Simplex Frequencies. Interestingly enough, it turned up a SERA webpage: their 2-Meter Frequency Utilization Plan: http://www.sera.org/2.html

It is interesting to note that they specifically list 146.520 as the National FM Voice Simplex Calling Frequency (emphasis on FM is mine). They do, however, have a listing of D-Star Voice Frequencies (the IMPORTANT NOTE is theirs):

146.420* 146.440* 146.460* 146.480* 147.420* 147.440*
147.460* 147.480*

IMPORTANT NOTE: = Frequencies marked with * are permitted for simplex use as long as it does not cause interference to nearby repeater inputs. Please be aware that SERA coordinates some of these frequencies as repeater inputs in some areas. Check the repeater directory in your area to see if any such repeaters are present. The use of these frequencies for D-Star operation, whether for simplex or repeater inputs, may impact FM simplex and repeater operations and their selection should be carefully considered.


Off the top of my head, none of these frequencies conflict with any of the Savannah repeater inputs. I would like to suggest that here in Savannah we use 146.460 for local area D-Star simplex because it is easy for folks to remember, especially if we're giving it to someone visiting the area. It is also worth mentioning that on the 70cm Frequency Utilization Plan they list 441.000 as the National Digital Simplex Calling Frequency.

Mac McCormick III, KF4LMT
kf4lmt@comcast.net