Stoke-on-Trent Repeaters 

20/03/2019

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First Switch On. No networking at this stage, standalone operation.

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13/03/2019

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Licensed today, it's time to get a move on. I was not expecting MOD/Ofcom to be this quick with the paperwork!

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02/03/2019

 

An application has been submitted to the ETCC for a Single Frequency Repeater (SFR) for the Stoke-on-Trent area, co-located with GB7SI.

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Terminal Information

 

Radio users wishing to use this repeater must configure the DMR terminal to monitor both time slots whilst in DMO (this is not standard DMR rmode. On some terminals, this is called a pseudo trunk.

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Not all brands of radios can operate in SFR mode. For example, TYT, Anytone, Baofeng, Retevis and other low-budget DMR sets do not support SFR mode. This is due to the VCO circuitry being unable to switch quickly (<90 milliseconds) between the time slots and underdeveloped Software/Firmware.

 

Upgrade to the latest firmware if using a professional radio, Motorola, Hytera, Simoco or Tait. Some manufacturers were late coming into SFR.

 

You will require an additional license key from your radio manufacturer to activate this optional feature in the terminal.

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Q&A

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Is the same frequency TX and RX?

In the world of DMR, it is possible to operate a DMR radio terminal via a single frequency repeater known as an SFR. 

 

How can this be possible? 

You have two time slots within a single 12.5KHz space, so operating a DMR radio terminal as a single frequency repeater is possible. 

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Voice or data information is received in SFR mode on the first time slot and re-transmitted on the second slot (90ms later) almost simultaneously.

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SFR enables the range of a direct link between conventional DMR devices in DMO mode to be extended without using a standard base station or repeater or change frequency.

 

This gives the radio user greater coverage using a single simplex 12.5KHz channel.