Ok i can see what your saying, Looks like it is a link.I just don't know know why they would be doing this.
Local frequency problems.. need help!
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Ok i can see what your saying, Looks like it is a link.I just don't know know why they would be doing this.
I know this thread is a little old but i thought i would bring it back because i have a bit of an update and a few questions.
First, i have discovered that the 33.1000 Mhz frequency is the primary control Chanel and the the 467.7875 Mhz frequency is a repeter, i think for the 33.1000 frequency. Also when i listen to my scanner i get his on the 33.1000 Frequncy but only if there is a bus near my house (Radius of like 2,000 Ft). Does anyone know why this is happening.
Second, i have reason to believe that all the UHF frequency that my school has may be apart of a trunked system. I also my be 100% wrong about this. But how does one discover a trucked system, i have read up about it but i am so confused. I have a BCT15X.
Thanks,
Nick
First, i have discovered that the 33.1000 Mhz frequency is the primary control Chanel and the the 467.7875 Mhz frequency is a repeter, i think for the 33.1000 frequency. Also when i listen to my scanner i get his on the 33.1000 Frequncy but only if there is a bus near my house (Radius of like 2,000 Ft). Does anyone know why this is happening.
Second, i have reason to believe that all the UHF frequency that my school has may be apart of a trunked system. I also my be 100% wrong about this. But how does one discover a trucked system, i have read up about it but i am so confused. I have a BCT15X.
Thanks,
Nick
WA0CBW
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The license indicates the UHF frequencies are mobile (MO) and not a repeater (FB2). They are only licensed for 2-watts each.
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This just all seems weird to me. I think it would just be easier if they used one frequency for the buses and they were all using one of the UHF frequency's, just my opinion but...
I am starting to get confused on this matter, can someone please explain to me, out of all the frequency SCSD has, how everything works? (Like how people talk to each other and on what frequency)
Thanks for your help
-Nick
I am starting to get confused on this matter, can someone please explain to me, out of all the frequency SCSD has, how everything works? (Like how people talk to each other and on what frequency)
Thanks for your help
-Nick
From what you have described it sounds like the buses and base station are on 33.100 simplex and the UHF frequency pair is used as a remote control link between the dispatcher and the base station.
While the UHF is not specifically licensed as a fixed repeater, it is not unusual for a 2 Watt UHF mobile license to be used for this purpose.
If you just use the stock little whip antenna on your scanner the range to receive mobiles on 33.100 will be very limited. Good Low Band reception requires a large outdoor antenna. If you can hear the UHF downlink then you are hearing everything the dispatcher hears.
The BCT 15x i have found is deaf on low band. At least mine is. hence why you only might hear a mobile radio close by. Try to find a good quality outdoor antenna ,Second reason might be there using 60 watts radios . not the 110 watts as used years ago. As i explained in a previous post using a UHF link is common. It saves money. No wire line to remote base site . Abel to use base from wide area of buildings. I'm more surprised there even still hanging on to low band since most everyone else bailed. Interesting to point out is the UHF license seems to be for Buildings and Grounds and maybe security. Looking at the FCC license Eligibility that is. Which makes sense for the 2 watts being used. So maybe were all over thinking all this. Might be as simple as a system on low band VHF for Transportation. And UHF ports for interior/Grounds use. Also not uncommon. Also maybe search the radio provider Reliable Communications, Inc and poke his freqs in. Maybe selling space to school from one of there towers 461.050,463.475,463.325.
ok thanks, i will try programing some of the Reliable Communications in to my scanner and see what i find.
Is there an advantage to this? is it just easier if everyone used the UHF frequency.
(As you can see i am new to this)
They may have had the Low Band for many years. It is also possible they can not get the coverage they need on UHF from their existing transmitter site. The low power UHF radios are used as a link between the dispatch office and the base radio site instead of the need to lease a phone line for remote control if the base station is off premises or in a different building on the campus.
I suspect this is a legacy system and it still works at lower cost that installing a full UHF repeater system. They may be in the process of moving to a leased UHF conventional or trunked repeater system to eventually replace the Low Band. UHF is pretty much line of sight coverage so you need a tower on the highest point in the area while Low Band is not shadowed as much by hills and valleys so the base sites is not as critical.
A lot of rural school buses have used Low Band radios since the 1960s when that was current technology and stuck with it but the trend now is to go to UHF. Leasing service on trunked systems is a cost effective way of getting wide area coverage without the need to maintain their own base station.
Up here in western NY a lot of school buses are on the Mobiletech LTR-NET system and they have coverage all around the area when they go to other towns for sports events and field trips. School buses from districts way down in the Souther Tier like Corning or Addison can come to Rochester and still talk back to their home district. LTR-Net uses multiple repeater sites over a wide area and the mobiles "roam" automatically to work with the closest tower, much like cellular, and the sites are tied together over the Internet so the dispatcher communicates from a computer and many system include GPS tracking.
Even LTR-NET is old technology now and digital DMR Capacity Plus and NEXEDGE systems are now getting many school bus users.
Ok thanks for explaining this,
But i just want to see if i can understand this, the dispatcher is using a base station that is broadcasting 33.1000. Then how does the UHF (467.7875) come into play?
If I understood your description of the situation correctly that you are hearing the buses on the 467 frequency then, at the 33.100 base station, the receiver audio from the buses is transmitted on 467 to the dispatcher. The dispatcher would reply on 462 and the dispatcher audio would be transmitted out over the 33.100 base station to the buses. The 33.100 base site may be located where you can hear the 467 transmission from that site but not the 462 side from the dispatcher's office up to the base site.
I am describing how the use of a UHF link for remote base control normally works and I am assuming it fits your description of what you are hearing. This type of "remote base" operation was common many years ago before repeater operation came into regular use. As someone mentioned, UHF repeaters are normally 462 transmit and 467 receive but this was not standard for control links so hearing the mobiles retransmitted on 467 does not surprise me.
I am sending you a PM with some more background information.
I am describing how the use of a UHF link for remote base control normally works and I am assuming it fits your description of what you are hearing. This type of "remote base" operation was common many years ago before repeater operation came into regular use. As someone mentioned, UHF repeaters are normally 462 transmit and 467 receive but this was not standard for control links so hearing the mobiles retransmitted on 467 does not surprise me.
I am sending you a PM with some more background information.
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They do the same "simulcasting" type usage with fire depts. that haven't gone over to a digital/trunk system, low band repeated via a multiple site uhf frequency.
It's the newer/cheaper technology/option for rural depts. They were doing that where I am for many years until they got the trunked system. They got rid of their low band radios but still use the analog 453/457 pairing for dispatching.
It's the newer/cheaper technology/option for rural depts. They were doing that where I am for many years until they got the trunked system. They got rid of their low band radios but still use the analog 453/457 pairing for dispatching.
radioman2001
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Sounds like a simplex UHF link to Low Band, and the dispatcher COULD have a 33.10 base(at the school) but it seems more like the system is a linked UHF to LB. Somers used to have their transmitter located on the water tank in Heritage Village. I ran the license and got that the transmitter is located at a private home in Lake Lincolndale or Shenorock. No where near the school or RT 202.
I had done the same for a VHF system years back for Ardsley Schools except I used a full duplex repeater so the base would have control if a mobile got stuck on the air.
I had done the same for a VHF system years back for Ardsley Schools except I used a full duplex repeater so the base would have control if a mobile got stuck on the air.
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You just solved the mystery!
Their license for 33.100 is confusing because it says the base station as well as the control point is at Sommers Jr High but the Lat/Lon coordinates on the license show that the base station is actually in a wooded area NW of Lake Lincolndale near Plum Brook between the dead end of Travis Rd and Sycamore Rd. But, I have been in contact with the Nick and he said there is no tower in that area.
Systems like this used to be common. Put a Low Band base on the local water tower and a UHF link back to the dispatcher with 2 watt UHF radios that were HT boards in a box with a power supply and a DC control interface to use instead of paying Telco for a dry pair lease line to the site.
radioman2001
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Been doing that for years, I put up a few from the Alpine Tower back to White Plains which is around 20-25 air miles. Amazing how far just 2 watts and set of high gain antennas facing each other get you. I have a feeling that the base location is at one of the principles of Metro Comm's (their radio shop)home.
I never used portables they couldn't handle the duty cycle, but a 30 watt mobile turned down to 2 watts would last forever. As I said before the only problem with a simplex link is a mobile can take over and the dispatcher can't key up. Not a good situation, that's why I used full duplex repeaters like a GR300.
There was also actually a low band station at Alpine linked to somewhere up in Rockland County in our room.It appears disconnected now.
I never used portables they couldn't handle the duty cycle, but a 30 watt mobile turned down to 2 watts would last forever. As I said before the only problem with a simplex link is a mobile can take over and the dispatcher can't key up. Not a good situation, that's why I used full duplex repeaters like a GR300.
There was also actually a low band station at Alpine linked to somewhere up in Rockland County in our room.It appears disconnected now.
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