Programming for ATV the GT Media V7+, DVB-T, Receiver

Jim Andrews, KH6HTV

We have recently discovered a new, low cost, combo DVB-S & DVB-T set-top box
receiver which will also tune the amateur 70cm & 33cm bands for DVB-T. It is the GT
Media V7+.

The receiver is specified to cover from 950 to 2150 MHz for DVB-S and 50 to 868 MHz
for DVB-T. However, I have tested it and found that it could be programmed as low as
50 MHz. It provides simultaneous digital and analog A/V outputs. They are 1080P
HDMI and 480i composite video plus stereo audio.

The receiver also includes a digital video recorder (DVR) function.

To use this, a USB memory stick needs to be plugged
into the USB port on the rear panel. The video is recorded as a .TS file, the same as used
for DVDs. The receiver operates on +12Vdc. It draws 0.4 Amps at +13.8Vdc
I also measured the sensitivity of the receiver. On the 70cm band it was -96dBm. On
the 33cm band it was -95dBm. This was measured using "normal" parameters of 1080P,
QPSK, 5/8 FEC, etc. I then added a low noise, 70cm preamp and it improved the 70cm
sensitivity from -96dBm to -99dBm. The preamp I used was my own KH6HTV model
70-LNA-1 with 21dB gain and 0.5dB noise figure

The instruction manual supplied with the receiver is very skimpy and essentially useless.
There are some You-Tube videos on the internet where users have tried to explain how to
set up the receiver, mainly for DVB-S satellite reception.

CHANNEL PROGRAMMING: Like all other modern, digital TV receivers,
such as you might buy. They come from the factory "dumb".

They have to be auto-scanned (i.e. programmed) to receive the available TV signals. To
do this, they must be exposed to valid DATV signals in the auto-scan process.

The first requirement to program the receiver for ATV use is to have available an RF
signal source with the correct frequency and bandwidth. The ideal situation is to hard
wire a direct connection from a DVB-T modulator to the antenna input on the receiver.
Suitable modulators are the Hi-Des model HV-100EH or model HV-320E as your signal
source. Either set the internal modulator attenuator to -20dB or greater, or use an
external coaxial attenuator of at least 20dB. This will prevent the high rf level from the
modulator from overdriving the receiver. Before proceeding with the following channel
programming instructions, connect the modulator directly to the receiver and set the
modulator to the desired frequency and bandwidth. It is helpful to also have "live" video
playing into the modulator, such as a DVD player.

Programming of the receiver is done using the supplied Remote Control.

VK3CE is part of the ever growing Australian Chapter of the World Wide Amateur Television Network

VK3CE Bendigo Victoria Australia