Input For LTR

[zzdiesel]

How does input work going into the repeaters? Is there an offset channel like in conventional systems used for the input, or how does it work?

 

[n4yek]

LTR systems are just basically conventional repeaters like you have always seen, but they have a controller that assigns transmissions to a particular frequency. Each agency will have a 'Home' repeater, but if it is busy it will assign it to a different frequency. Once the 'Home' repeater is available again, all transmissions will go back to it.
Now if you have an LTR system that has multiple sites for a Wide Coverage area, then the LTR system will have 'Link' frequencies between the sites themselves.
My local LTR system is a UHF system, but the sites are linked together on 800 MHz.

 

[zzdiesel]

Thanks. The reason I ask is that our county Sheriff's dept is about a mile from my house and the repeater is about 20 to 25 miles away. I feel I could probably hear the base better directly instead of through the tower.

 

[n4yek]

Thanks. The reason I ask is that our county Sheriff's dept is about a mile from my house and the repeater is about 20 to 25 miles away. I feel I could probably hear the base better directly instead of through the tower.

Possible, but they might have a beam antenna pointed to the tower. If you happen to be on the back side of the beam you would most likely not hear it very well. Then also you would have to consider that you would hear the dispatcher talking to the tower, but most likely would not hear any replies from the vehicles unless they were close to you.

 

[zzdiesel]

Ordinarily I would agree with you. This system is silly. I can barely hear their base on the repeater but the cars come in loud & clear. You'd think it would be the other way around but it's not.

 

[zzdiesel]

Is there an offset input channel or does the repeaters rebroadcast the users?

 

[pachanga22]

Ordinarily I would agree with you. This system is silly. I can barely hear their base on the repeater but the cars come in loud & clear. You'd think it would be the other way around but it's not.

I think what I just read is that the base antenna is broken...

 

[N_Jay]

Ordinarily I would agree with you. This system is silly. I can barely hear their base on the repeater but the cars come in loud & clear. You'd think it would be the other way around but it's not.

Barely hear as in scratchy, or barely hear as in soft?

 

[silverbk]

Is there an offset input channel or does the repeaters rebroadcast the users?

On a UHF system it is usually a standard 5mhz offset. The repeaters simply repeat what they hear. Generally when a unit goes out of range, you will not hear them at all as their radio will not work unless it can "hear" the strobe on the home repeater.

 

[w8jjr]

then there are others that confuse things Input of 429 and output of 460.
Rare but there are split input freq's.

 

[N_Jay]

then there are others that confuse things Input of 429 and output of 460.
Rare but there are split input freq's.

Where?

 

[silverbk]

then there are others that confuse things Input of 429 and output of 460.
Rare but there are split input freq's.

That would be very unusual, as you would need to find just the right LTR radio to handle that split. Are you sure that they are not using the 429 mhz frequency as a link to another site?

 

[ecps92]

Actually, +5 Mhz on 451-465 Mhz and +3 Mhz on 470 Mhz thru 512 Mhz

On a UHF system it is usually a standard 5mhz offset. The repeaters simply repeat what they hear. Generally when a unit goes out of range, you will not hear them at all as their radio will not work unless it can "hear" the strobe on the home repeater.

 

[ecps92]

Who is using 429 Mhz in North America ??

then there are others that confuse things Input of 429 and output of 460.
Rare but there are split input freq's.

 

[pachanga22]

Who is using 429 Mhz in North America ??

military

 

[silverbk]

Who is using 429 Mhz in North America ??

Based on the OP callsign I searched the FCC database for trunked licenses from 427 - 429 mhz and low and behold many hits.

It seems that in the Detroit area there are a bunch of systems operating from 420 to 430 mhz including a few conventional. They can be verified on the Oakland county Michigan page of this website.

I did not find any using frequencies in both 420 and 460 mhz range as the OP suggested.

Actually I think it would be kinda cool to live out there, you could purchase very very cheap radios to get on the air. 420 radios sell for pennies on Ebay.

Maybe someone from the area can chime in? I would guess that their proximity to Canada has something to do with the licenses for 420. It's exactly the opposite situation in most other areas where you a forbidden to transmit in that range near Canada.

 

[ecps92]

Can you be more specific, other than just Military.

406-420 is the Federal Band
440-450 is the Amateur Shared with Pave-Paws, not LMR

military

 

[silverbk]

Take a look at this thread:

70CM "440" Ham Band - Page 2 - QRZ Forums

Also see this page:

Oakland County, Michigan (MI) Scanner Frequencies and Radio Frequency Reference

You will conventional and trunked systems at 420 mhz

Remember the 70cm ham band is 420 to 450 mhz and we are secondary users. Since hams cannot operate drom 420 to 440 north of Line A The FCC has granted licenses for 420 for commercial and public safety users.

As you pointed out PAVE/PAWS is the primary user in 70cm and I actually have a power limitation on my repeater in Newport Rhode Island so I do not interfere with them. They did manage to shut down the N1JBC repeater (at least the 70cm side) in Coventry last year.

 

[ecps92]

Thanks

Take a look at this thread:

70CM "440" Ham Band - Page 2 - QRZ Forums

Also see this page:

Oakland County, Michigan (MI) Scanner Frequencies and Radio Frequency Reference

You will conventional and trunked systems at 420 mhz

Remember the 70cm ham band is 420 to 450 mhz and we are secondary users. Since hams cannot operate drom 420 to 440 north of Line A The FCC has granted licenses for 420 for commercial and public safety users.

As you pointed out PAVE/PAWS is the primary user in 70cm and I actually have a power limitation on my repeater in Newport Rhode Island so I do not interfere with them. They did manage to shut down the N1JBC repeater (at least the 70cm side) in Coventry last year.

 

[N_Jay]

Interesting, but I would hazard a guess that any system using a 429 input and a 460 output is improperly constructed at the least, and probably improperly licensed (or illegal).

Still wondering where this supposed system is?