Germanna Community College

N4VKF

Member
Premium Subscriber
Joined
Jul 11, 2002
Messages
693
Location
Spotsylvania, Virginia
I've been monitoring a DMR signal on the listed callbox frequency of 452.850. I am trying to figure out if they made a change from analog to DMR.
My monitoring as not discovered any color codes. Is it just interference from another transmitter overloading my receiver from the
other Fredericksburg cap plus system. The scanner displays a CAP+ icon. I have not discovered the signal which may be a control channel
on any of their additional licensed frequencies. Is someone able to assist with verifying what I am listening to?
 

W4UVV

Member
Joined
Nov 9, 2002
Messages
1,612
Location
Prince George, Virginia--Central Va.
N4VKF,

1. I checked my frequency database. Germanna Community College, like other state colleges with a radio system, is funded by state taxpayers. Therefore, VITA techs in Chesterfield Co. via an IP also can control the GCC radio system from their Chesterfield Co. location.

2. However, doing research I discovered after initial licensing of 452.8500 mhz., in 2009 WQHH215 was modified. The modified license, I suspect, was to incorporate the new GCC location in Culpeper Co. Additional DMR (MOTOTRBO) frequencies were added resulting in a DMR Capacity Plus, 4 sites via internet IP control. I doubt the Fredericksburg Office is causing you any tech problems. You missed the additional frequencies. Try assigning the default color code "1" to "452.8500 mhz." and "2" to "461.3875 mhz." as a next logical relationship. If no success remove the "2" only.

3. DMR Capacity Plus system site locations via IP control: (1) GCC Locust Grove
(2) GCC Fredericksburg Office
(3) GCC Culpeper Branch
(4) Chesterfield Co. Tech (Control)
4. WHQQ215 DMR frequencies:

Repeaters:
452.8500 mhz.
461.3875 mhz.

Simplex:
462.0250 mhz.

5. Authorized emissions: 11K2F3E(Analog 12khz. deviation) or 11K2F1D(Analog 12khz deviation or 8K10FIE(P25 Phase 1 C4FM) or 7K60FXE (DMR).

6. Radio system users include: Campus Security, Maintenance, Administrative and Callbox

7. My conclusion remains unchanged......DMR(MOTOTRBO) for "normal" radio comms. However, a "callbox" emission mode typically was "analog" because it involved a telephone voice interface on the other end.

Hope this helps. If not, now you may be more confused. Ask a monitor friend within monitoring range of GCC to configure a DMD. It looks to me like a typical MOTOTRBO Capacity 2 Plus 4 site trs with IP internet control. My data base for new/updated trs mainly now are these type of DMD systems.

Good Luck!

John:)
W4UVV
 
Last edited:
Top