Voters?

[JethrowJohnson]

I've been hearing of some analog conventional systems that use voters either instead of or along with repeaters. But what exactly are voters?

 

[AK9R]

Imagine an analog repeater system with a receiver at the main repeater site and multiple remote receive sites. The remote receivers are linked back to the main site via RF, microwave, leased line, fiber, etc. Depending on where any particular user is located, more than one remote receiver may hear the user's radio. As a result, multiple received signals hit the main site. So, the main site has to decide which receiver to route to the output of the repeater. That's the job of the voter.

 

[Thunderknight]

To add to that description, typically, the idea is to improve coverage for portable radios. The repeater may transmit at 100 watts, but the portables only at 5 watts. So they will not have the same talk-back range that the repeater talks out with. Adding in voted receive sites will make up that difference, picking up the portables where the main repeater can not hear them.
In a simulcast (trunked or non-trunked) system, each transmit site is typically also a voted receive site. Otherwise if only one site was receiving and all of them transmitting, the system would be heard much better than the field units would be talking back.

 

[GTR8000]

It's worth noting that the official name of a voter is comparator. It literally votes on the best signal it's receiving from multiple receivers by comparing them (hence the name comparator), with the ability to route the inbound audio from any receiver out through the repeater(s). It can switch sources in real time fractions of a second apart. So if a vehicle is traveling at 80 MPH and is between 2-3 voted sites, the resulting audio being output through the repeater(s) can actually have switched between those 2-3 sites multiple times within a 15-20 second transmission.

And just to clarify, voters/comparators do not replace repeaters, rather they are used in conjunction with repeaters to enhance inbound coverage and to ensure that the best audio makes it back out.

 

[W9WSS]

Remember most comparators base the "voted" signal on signal quality, not signal strength.any times, a mobile or portable will unsquelch all the receive sites, but will still "vote" the best quality sounding, not the strongest signal. Again, this is for a typical Motorola analog Spectra-Tac system. I was in charge of our agency's 800 Mhz. two-channel 5 site repeater system from 1986 to approximately 1992. It was a true labor of love for me.

 

[12dbsinad]

And the new generation will never know about the cool sounds of a analog voting system.

 

[W9WSS]

Most, if not all Motorola Spectra-Tac voter/comparators were replaced by a company called JPS. I was already out of the maintenance of our police radio system when the JPS was put into service and the Motorola Voter/Comparator was removed.

 

[70cutlass442]

I maintain a JPS SNV12 for our PD. We just switched to P25 so we are repurposing the voted system for our DPW/backup PD channel.
Both have their advantages.

 

[JethrowJohnson]

Thank you everybody for your answers and explanations! It's basically like an analog simulcast system in a way, except that the voters choose the best quality signal to use instead of all of them?

And the new generation will never know about the cool sounds of a analog voting system.

What do they sound like? Our analog system only has one repeater.

 

[12dbsinad]

Thank you everybody for your answers and explanations! It's basically like an analog simulcast system in a way, except that the voters choose the best quality signal to use instead of all of them?

What do they sound like? Our analog system only has one repeater.

More so of the Motorola Spectra-tac, you will hear the distinctive "click" when a user un-keys (audio clamping), as well as the famous "Bee-Doop" of tone signaling before the guard tone is muted.

Today, you just hear digital R2D2 no matter what the system is comprised of.

 

[nd5y]

And the new generation will never know about the cool sounds of a analog voting system.

What cool sounds? I always thought that if you could hear clicks and tone remote tones it was due to poor engineering.

 

[AK9R]

It's basically like an analog simulcast system...

A simulcast system would have multiple transmit/receive sites all transmitting the same signal. In a voted system, there is one transmit site and multiple receive sites.

 

[12dbsinad]

What cool sounds? I always thought that if you could hear clicks and tone remote tones it was due to poor engineering.

Tell that to every old Motorola system that ever existed. You hear it. On the newer JPS SN-12 comparators you don’t hear much of anything, but will still hear a tone bleep if a RX site is still active and the control station transmits.

 

[nd5y]

A simulcast system would have multiple transmit/receive sites all transmitting the same signal. In a voted system, there is one transmit site and multiple receive sites.

Simulcast systems can also have voted receive sites and there can be more receive sites than transmit sites.

 

[speedway_navigator]

I made this video on simulcast and voting systems.

 

[Reelfishguy]

The old GE voters were excellent--worked on quite a few of those. Just watch the lights on the front when someone would key up and then switch between sites. When properly set up, no clicks between sites.

 

[hp8920]

It's basically like an analog simulcast system in a way, except that the voters choose the best quality signal to use instead of all of them?

Put another way, a simulcast system is simul-transmit. A voter/comparator system is a simul-receive.

 

[GTR8000]

And a voted simulcast system is a simul-transceive!

 

[KevinC]

And a voted simulcast system is a simul-transceive!

How about a steered TX and voted RX system?

 

[mmckenna]

How about a steered TX and voted RX system?

That uses PFM.