Lots of radio checks on First Tac 7
Protests / Riots
- Thread starter trimmerj
- Start date
- Status
tvengr
Well Known Member
Looks like they never got the 4 frequencies.
WRCJ218, WRCJ217. They're also spec'ed for the BDAs that developers must include in certain new construction.
tvengr
Well Known Member
We will probably see them with the new P25 system.
Yup, that's what I was trying to express when I mentioned the new system. They were not able to secure channels to move into the NPSPAC band with the Nextel swap, and can only get 4 of 12 for the new system. They do use NPSPAC RINS channels for the VRS. Still noticeable interference from time to time on existing channels.
Last edited:
tvengr
Well Known Member
The v3_60 firmware update added the capability to receive 800 MHz rebanded Motorola systems. That is not required for the Anne Arundel system. If you update the firmware, it will have no effect on the AA system. What version firmware do you have?
Anyone know if I should be able to receive Baltimore City from the Towson area? Seems I am having some trouble.
What radio do you have? The closest tower site is at Good Samaritan Hospital at about 9 miles SE, but I think the site on TV Hill would provide better coverage to the Towson area, but it's roughly 10 miles away - a bit of a stretch considering terrain and structures in the signal path..
Forget about the ranges I stated above - those are to Timonium. lol. It's 3.2 miles to central Towson from the Good Samaritan site, and 5.3 miles from the TV Hill site. That would be well within the range of a typical P25P1 site with an omni antenna 300' in the air for on-street coverage. But if these sites have antennas designed to shape coverage to remain more or less within city boundaries by tilting and / or directionality, it is possible the signal *may* not be receivable in Towson. Unfortunately, antenna orientation data is missing from the FCC database for this callsign. And if you are using a non-optimized radio or inappropriate antenna, you *may* not be able to receive the city system in Towson.
Currently I am only using the antennas that came with my rtl sdrs so I totally get that I am not receiving anything. I also am sorta discouraged from having any external antennas so maybe a discone in the attic is a alternative?
What software are you using?
SDR Trunk, I am planning on getting DSD Fastlane and comparing them.
Yes and it seems I have some signal but a lot of lost bits.
Edit: Upped the gain and seems I am now receiving but still getting sync loss. Also seems my second monitor cable was hitting the USB cable. Weird thing is that it has not affected other systems I monitor.
Edit: Upped the gain and seems I am now receiving but still getting sync loss. Also seems my second monitor cable was hitting the USB cable. Weird thing is that it has not affected other systems I monitor.
Last edited:
tvengr
Well Known Member
Baltimore City is presently using 853.8750 as the control channel.
I have never used SDR Trunk, so I cannot evaluate how well it handles simulcast and LSM. You are more or less equidistant and not exceedingly far from at least two tower sites, so I am suspicious. Maybe there is some local interference. What SDRs do you own, and have they been calibrated for ppm error?
Seems that upping the gain and turning of the extra monitor did the trick.
Yea, I was up north of Baltimore today, no problem receiving the Baltimore City system at the Carver Center in Towson. Good signal on I-83 North until Timonium Road where it begins to degrade. I did notice considerable noise according to the SDS200; not sure what that actually measures. Some amount of D-error as well. UT2 showed a 100% decode rate, and ~-50dB RSSI, which is a strong signal at the Carver Center.
Meanwhile, a peaceful protest is going on right now in Annapolis; several streets in the vicinity of Forest Drive and Chinquapin Round Road and into downtown closed. The usual Annapolis tgs on the AACo system in use.
Noticed several MSP Tac pickups with license plate readers deployed on the roads today.
- Status
Similar threads
