Technical

“DATV Repeater v2.0” Controller; as described in CQ-TV, Spring 2022:  when you transmit into the repeater there will be a smooth audio and video transition from the media server to the active input. A “lower third” graphic announces every access and a “k” graphic is displayed at the end of each transmission. Every 10 minutes a subtle “lower third” ident graphic is also displayed. The repeater is available 24×7. During the evening GB3JV transmits a series of presentations about Amateur TV and Radio. The intention is that these presentations will help encourage more recruits to the ATV side of the hobby. If you would like to contribute to the content or graphics please feel free to contact Justin, G8YTZ as he’s very keen to encourage experimentation and creativity in TV production as another aspect of the DATV hobby. After midnight the repeater transmits Colour Bars with Lindos LA100 test tones and frequency sweeps for audio alignment.

How GB3JV Routes Incoming Signals

RF Output: 3.404MHz: The repeater uses an SR-Systems “HD-Mod” Exciter, driving a  “Kuhne” 3.4GHz up-converter which provides excellent transmission MER. The output uses a Symbol Rate of 2MS/s and an FEC of 4/5 with an ERP of 150W from an omnidirectional “Slotted Waveguide” Antenna. The Transmitting antenna is 15m AGL.

Repeater Streamer: Is active; URL for VLC and other H.264 media players is: rtmp://rtmp.batc.org.uk/live/gb3jv

23cm Input: The repeater’s 23cm input (1249MHz) supports 333kS/s and 2000 kS/s from a West Facing Antenna. This input is VERY sensitive!

70cm Input: The repeater’s 70cm input (437MHz) supports 333kS/s and 1000kS/s. from an omnidirectional “Big Wheel” antenna with a gain of 5dBi. Results indicate that this input, like the 23cm input is also VERY sensitive, so access from “over the hills and far away” is entirely possible!

2m “talkback” Input: A receiver tuned to the ATV calling channel 144.750MHz FM/Vertical, CTCSS 103.5Hz is required to access the talk-back feature.

Repeater Stream Input: This is now operational, for a stream key please register at www.gb3jv.co.uk Please note that you need to be a licensed radio amateur of intermediate or full license grade and either a member of the BATC or a local radio club.

Last in First Out: If another OM is already using the repeater and a second OM transmits on the unused input, the second station takes priority over the repeater. Planned for later on is a “PiP” function where the second station will appear as a “Picture in Picture”.

Session Recording: As a registered user, when you log into the web site you’ll see a new top menu item “Session Recordings” The link on this page will take you to a Microsoft OneDrive page where the recordings can be played in a compatible browser or downloaded. Recordings are generally available within 4 hours of your repeater session. The intention of these recordings is to enable repeater users to evaluate the technical quality of their transmissions and to offer evidence of contacts made, perhaps in a contest. The recording quality and data rate is identical to the BATC web stream. Please see the updated privacy policy.

Audio Announcements: When you access the repeater you’ll get an input specific welcome from a friendly voice, and when you leave you’ll get a polite “goodbye”. We’ve also added audio “time checks” at the top of each hour. Enjoy!

Slack Channel: When you register at www.gb3jv.co.uk you’ll also receive an invitation to join the GB3JV SLACK channel. This channel will send you a notification via the SLACK app whenever the repeater is accessed, there are other exciting developments in the pipeline too! The SLACK app is available for Mac, Windows, Linux, Apple iOS and Android.

Test Card and Music: We “hear” at GB3JV play tribute to Angus McKenzie in offering the very best high-fidelity audio and video quality. We’ve introduced music at certain times of the day as well as audio test tones overnight to test the audio as well as the video performance of the repeater. The Lindos LA100 audio test tones are sent at -18dB relative to peak full scale. Music is supplied by Artlist, details on www.gb3jv.co.uk