Welcome aboard GB3JT — your DATV adventure starts here!

Good news: getting on board is easier (and cheaper) than you might think. In fact, you may already have the most important piece of kit sitting in your living room. Let’s get you set up ready for when GB3JT launches!

What you’ll need to pack

• A 23cm Yagi antenna — a small one will do just fine, plus a bit of feeder cable to go with it.
• An HD satellite receiver — and it really does need to be HD. Here’s the good news though: the satellite tuner built into most modern TVs will do the job beautifully. We’ve tested LG, Samsung and Sony with great results.
• A small inline amplifier — to make up for cable losses at 23cm. You’ll find one on Amazon for under £10. Bargain.
• A little time and patience — though honestly, not much of either!

Before you do anything else, take a look at the 23cm coverage map on this website. If you’re in the “green” zone with a clear view towards Detling Hill — no tall trees or buildings in the way — you’re already in great shape. Not sure? Just drop Justin G8YTZ a line (you’ll find him on QRZ) and he’ll be happy to help.

Choosing your antenna

You’ll find 23cm Yagi antennas at most amateur radio suppliers, but our top pick is Antenna Amplifiers — Goran really knows his stuff. We’d recommend one of these two:

• The 5-element compact antenna — neat, tidy, and gets the job done.
• The 13-element antenna — if you fancy a bit more oomph.

Two important things: Go for the Wideband version. And if you think you might want to transmit into the repeater one day, the 23/70 dual-band version is well worth having. One thing to watch — some antennas look like a short circuit to DC, which will stop your little amp in its tracks. The antennas we recommend are all open circuit to DC, or you can buy a “DC Block” device on Amazon so you’re good.

Thinking about transmitting? You’ll want a coaxial switch to protect that little amplifier when you key up. And if RF transmission isn’t an option for you right now, no worries — you can stream straight into the repeater from your phone or via OBS. Check out the “Streamer Key and Instructions” page for the details.

Ideally the antenna goes outside — on a chimney or similar. But don’t let that put you off. The 5-element dual-band antenna can be used to receive GB3JT from up to 20 miles away, even with the antenna in a loft, so loft mounting is definitely worth a try!

Getting your antenna installed

Get a competent person to fit the antenna — a chimney or existing TV pole are ideal spots. We’d suggest a short run of quality coax from the antenna down to the loft, then a longer run of satellite cable from there to your receiver. Pop the inline amplifier at the changeover point, in the loft.

Keep the amplifier indoors — damp and electronics aren’t great friends. And keep that unamplified section of cable (antenna to amplifier) as short as you can. High-quality coax is good; a short run of Heliax is even better.

Setting up your receiver

Whether it’s built into your TV or a separate box, most satellite tuners work in a similar way. Here’s what to do:

Step 1 — Create a new satellite and dial in these settings:

• LNB Local Oscillator: 5150 MHz — this keeps your blind scan nice and quick.
• Symbol Rate: 2000 kSym/s (or 2 MSym/s — same thing, different receiver).
• Polarisation: Horizontal or Vertical — your call, either works. There’s no LNB here; this setting just determines the voltage fed to your inline amplifier.
• 22kHz Tone: OFF — important! This tone is used on normal satellite setups to switch LNB bands. You don’t need it, and it could cause mischief.
• LNB Power: ON — this is what keeps your inline amplifier alive.
• DiSEqC: OFF

Step 2 — Run a blind scan. Head to your blind scan settings and let it run. It’ll take a little while as it works through the tuning range. If your signal is good enough, the receiver will lock on to GB3JT and add it to your channel list. And then — magic — you’ll see the picture!

No antenna? No problem!

You can still get involved by streaming into the repeater from your phone or via OBS on your PC. Head to the “Streamer Key and Instructions” page and we’ll get you sorted.

One more thing…

Come and join the British Amateur Television Club: batc.org.uk. Now sit back, enjoy the picture, and welcome to the wonderful world of Digital ATV. We’re really glad you’re here!

Meet the brain behind GB3JT — the “DATV Repeater v2.0” Controller
(as described in CQ-TV, Spring 2022)

When you transmit into the repeater, the switchover is seamless — a smooth audio and video transition brings your signal to air without any of the ugly cuts you might expect. A “lower third” graphic announces every access, and a neat “k” graphic signs you off at the end of your transmission. Very professional!

GB3JT is on the air 24×7, so you can drop in whenever suits you. In the evenings we run a series of presentations about Amateur TV and Radio — designed to inspire the next generation of ATV operators and hopefully tempt a few more people into the hobby.

Fancy getting involved? If you’d like to contribute content or graphics, Justin G8YTZ would absolutely love to hear from you — he’s passionate about creativity and experimentation in TV production and welcomes fresh ideas with open arms.

There’s also a YouTube video walking you through the latest features of the repeater design — well worth a watch!