Introduction to Analogue Radio Programming

• Radios work in simplex or half duplex mode.

• Instead of TX & RX we use BTX & MTX.

• Base Tx (BTX)

• Mobile Tx (MTX)

• In the UK BTX is low but there are exceptions.  In Europe BTX is generally high.

• Beware of camera data.  It tends to be used on a similar frequency.

• Standard power used in the UK is 5W BTX and 1W MTX.

• The channel width we use is typically 12.5Hz though there are a few 25Hz channels.

• Most RF equipment we own operates between 400-470MHz.

•B/R: Base Stations

•M: (Taxi cab) Mobile

•P:  Portable

• Opens the audio monitor as soon as there is sufficient amplitude at the set Rx frequency.  Even a carrier harmonic can be enough to open the squelch.

• Only used to the base TX of a line connected base as its never switched off during a show.

• Not advisable to use on repeaters as the constant opening of the carrier squelch will be “off-putting” for the end user.

• It’s a Motorola Compression algorithm so don’t use it on channels using Tait Base stations.

• They both mean the same thing.

• Throws away the high- and low-end audio to make the mid’s more intelligible.

• When interfacing a base station into comms other you’ll need to take the reply audio and feed it back into the transmitter if you want other radio users to hear the reply feed.

• In an OB environment this is done in the scanner truck so there is no input required from us.

• When achieving this “in-house” best practice is to use a Prospect Matrix mixer or equivalent.

Polite Tx checks the airwaves to see if any RF before Transmitting.  It can check one of 3 things:

Carrier

• Scans the raw RF before transmitting.  Never use this as the system will never work, especially in a noisy environment.

• If you press the PTT on your radio and you keep getting “channel busy” then its most likely set to “carrier free”.

• Some programming suites may allow you to change the threshold.  If so, then the default is normally set to the minimum level.

PL

•Checks the frequency for a Valid PL or DPL Code.

Colour Code (Digital only)

•Same principle as PL but checks the network Color Code. 

•Impolite Tx just transmits regardless.  This is referred to as “Always” in the CPS.

Where possible use “Always”.

• There are some situations (e.g., CAP+) which won’t let you use “Always”.  In this case use “PL/Color code free”.

• TOTs are useful to prevent accidental transmission.

• Always use a “Non-Cumulative” TOT as this ensures the timer resets after the PTT is released.

• The radio will Give an audible alert when 10 seconds remain.

• A TOT Delay or Re-Key sets the amount of time the user must wait before transmitting again.

• Make sure this is set to 0.

This is the main window on the GP programming software.  The sections we are interested in are:

•Per Radio.

•Per Channel.

•Per Personality.

The per Radio Section contains all the options that always apply to the radio.  These include:

•Welcome & Prefix messages.

•RF Power level.

•Menu items.

•Button definitions.

•Microphone gain.

• TX & RX frequencies as well as channel spacing and power level.

• The Display tab is where you give your channel a name.

• Greyed out on non-screen models.

• 16-character limit.

•PL/DPL is where you set the PL codes as well as their type.

•This is where the Reverse burst tick box is.  Enable it to avoid the audio splat.

•The Misc. section allows you to lock down a bit more with the use of tick boxes and personalities. 

You apply these settings to groups of channels, and they allow you to set admit criteria.

• At most you’ll have 3 personalities.

In Tx/Rx you can set the TX admit criteria as well as a Tx timeout timer.

• We only ever use Always & Never Allowed.

• Time out Timer settings are here too.

In Squelch you set the RX admit criteria.

• We use “PL/DPL & Carrier Squelch”.

•DO NOT tick Reverse Squelch!

We don’t use the misc. tab though the VOX settings are there if you need them.

On the Audio Tab you want to make sure Voice Pre-emphasis is enabled.

• It’s also a good idea to enable XPAND (also known as Companding) if you are not using Taits.

• This is the main window on the GP programming software.  

• Personalities aren’t used so everything is done on a per channel basis (which are called Personalities).

• Make sure you’re in expert mode (Identifiable by the Mortarboard in the bottom right of the screen).

• This is the main window on the CP programming software.  

• Personalities aren’t used so everything is done on a per channel basis (which are called Personalities).

• Make sure you’re in expert mode (Identifiable by the Mortarboard in the bottom right of the screen).

• A couple of differences

• Companding is the same as XPAND.

• A PL code is called a TPL.

• Everything inside the grey box can be copied.

• Make sure the “DPL Turn-Off Code” is ticked and “TPL Reverse Burst” is set to standard.

• Make sure Busy Channel Lockout is set to disabled.

•This is the main channel window for the TB7100.  It consist of two separate modules so you’ll need separate Tx & Rx files.

•Each board will only need to know about specific variables.

Tx needs:

• Tx Frequency.

• Tx PL (if used).

• Power level.

• Network.

• Bandwidth.

Rx needs:

• Rx frequency.

• Rx PL.

• Network.

• Bandwidth.

• Squelch type.

• Try to use known good files where possible.  This keeps all the pre-set defaults the same.

• Power varies between a 25W & 40W.  Make sure you plan how that power goes through the system.

• If you’re mixing the H5 & H6 bands, you’ll need to change the band in specification tab.

• Depending on the environment you may want to change the Squelch sensitivity.  Most of the time we use country Squelch but in busy environments you may want to switch to City or hard Squelch.