HFU HF Underground
Loggings => VHF/UHF Logs, including satellites and radiosondes => Topic started by: ChrisSmolinski on March 25, 2021, 1354 UTC
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I recently removed the in line pre-amp from my discone (which I think was causing more grief than good) and bypassed the splitter and am directly feeding one receiver (the AirSpy) for maximum signals and SNR. I think this setup works best. Now I need to find a decent VHF/UHF antenna switch.
160.980 @ 1328 UTC 25 March 2021. After years of trying... I have finally heard my first railroad communications.
160.995 Another RR related? Weak
161.3225 Remote pickup - not sure who this is, SS YL heard @ 1332 UTC. Weak and fading in and out.
161.445 Another railroad?
161.6375 Another remote pickup. Fox News maybe?
450.4125 TV auxiliary remote transmission for WGAL ch 8.
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The 161.670 MHz to 161.790 STL/remote broadcast pickup band regulations permit use of offset frequencies, 15 kHz or 7.5 kHz offsets...putting that band in-line with the standard 7.5 kHz VHF high band band plan:
161.6700 MHz
161.6775 MHz - offset
161.6850 MHz - offset
161.6925 MHz - offset
161.7000 MHz
161.7075 MHz - offset
...
up to
161.7825 MHz - offset
161.7900 MHz
The railroad band is another interesting segment - 160.2000 MHz to 161.5650 MHz...15 kHz / 7.5 kHz channel steps. Most railroads are still using the 15 kHz channel steps but the railroads are updating their licenses for NXDN (aka NEXEDGE) narrowband digital voice (4K00F1E emission). I live in a city that operates as a major railroad junction for CSX, Norfolk Southern and Amtrak and I'm yet to hear any digital voice on the railroad frequencies. All the activity is also still on the 15 kHz channels.
The railroad systems are interesting compared to other land mobile systems in that they're relatively low powered (usually the base stations are licensed for 20-50 watts output power) and there's very little use of CTCSS. There's a massive CSX classification yard about 1 mile straightline distance from my QTH and yard control radio is very active - same with the Maintenance of Way channels (which are usually also within the 160.200 to 161.5650 AAR railroad band) The yard also uses a voice/data paging system on 462.925 MHz...also licensed for 25 watts. The most active frequencies are the road and yard control frequencies, which can be monitored on a handheld radio easily.
Also check out the HOTD/EOTD (Head-Of-Train-Device and End-Of-Train-Device) UHF telemetry frequencies are other ones to look at:
452.9375 MHz
457.9375 MHz
There are other telemetry/datalink frequencies used by railroads, including others in the 452.9250 MHz - 452.9750 MHz range, the 44.5800 MHz BNSF telemetry network and others.
A few weeks ago I monitored a drone operating crew that was using a drone to survey/inspect a railroad right-of-way...they were using 151.8050 MHz (which is one of the regular old VHF high band business/industrial radio service frequencies). One of them sounded like they were in a chase vehicle while the other was in a fixed position. The itinerant frequencies are also sometimes used (VHF high band itinerants are 151.5050 MHz, 151.5125 MHz, 151.6250 MHz, 151.7000 MHz, 151.7600 MHz, 154.5275 MHz, 158.4000 MHz and 158.4075 MHz).
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I know that when I was a Test Tech for testing the radios on the Atlanta, GA MARTA (Metro Atlanta Rail Transit Authority.), they had Motorola 800MHz, Israeli made, rigs installed. In order to test the radios, we requested an HT programmed for the MARTA FREQ's and PL tones. They did, but no charger! Needless to say, my tests were brief. Still, interesting insights there.
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The first RP, 161.3225, isn't listed in the ULS DB. Maybe .31? But nothing in MD for RP on 161.31.
That second RP is 161.64. ULS has a bunch of licensees for your state. I can't tell who it is, but shouldn't be hard to determine by listening a bit. Should be able to easily determine if TV or radio (I'd bet a couple of bucks on TV), then tune that thing around to match.
For the railroads in MD: https://www.radioreference.com/apps/db/?aid=2159
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Don’t forget about Positive Train Control (PTC) on 220 MHz. It’s all digital I believe. I see their equipment along my local train tracks.
https://www.radioreference.com/apps/db/?aid=7747
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Congratulations. I've been trying to pick up both rails and AIS for a while now. Virginia rail is theoretically close enough for me to pick it up, but I've never heard anything. I should be able to pick up AIS from ships in the Potomac but, once again, nada.