GB3BN new logic

[Chris, G4CCC]

Today, at around 12.30, the GB3BN repeater at Bracknell was replaced with different RF equipment and logic. The repeater now has CTCSS (Continuous Tone Coded Squelch System) only access. This is to reduce interference from low power devices (also referred to as short range devices), such as crane anti-collision radar and industrial remote control devices.  Please see the attached document, which explains how the new logic works. 

In particular, based on what I've heard over the last couple of hours, please note that a single "PTT blip" will not bring up the repeater, you need over two seconds of carrier to latch the logic, preferably accompanied with your callsign.

Chris, G4CCC.

o/b/o Thames Valley Repeater Group.

[Bill Somerville]

On 12/08/2021 14:32, 'Chris, G4CCC' via Reading and District Amateur

Thanks to you, Denis, and the TVRG,

my initial report:

1) the new logic will be a great improvement in the presence of
interference on the input frequency,

2) the repeater output power seems to be down by roughly 1 dB,

3) as noted by Loz, G2DD, and others, some users cause a squelch tail to
be relayed through the repeater,

4) a short access that invokes the quick shutdown procedure has an
undesired feature, the output CTCSS tone stays on right up to the point
output carrier drops, this invokes an undesirable squelch tail on
monitoring receivers even if they have tone squelch enabled,

5) the output frequency seems good, about 110 Hz high,

6) the output CTCSS tone seems accurate at 118.8 Hz,

7) input sensitivity seems unchanged from the old rig.

73
Bill
G4WJS.