Friday, 5 August 2011

One step closer to getting a decent signal out

I finally got a response from my local council about erecting a
proper mast for my DATV activities. The council in fact replied
to me about a month ago but the letter appears to have got lost
in the post. The view of the planning officer is that they are likely
to grant me permission as the plans are in line with the local
development plan and the structure is not excessive. It is likely
that the mast will have to be retracted when not in use as a
condition of the permission.

One slight fly in the ointment is that they will require a
"Telecommunications - Supplementary information" form to
be submitted with the application. This appears to be a
document design for cellphone antennas and asks many
questions which are not applicable to Amateur Radio.
Including whether I have coordinated my installation with
others operators, expected coverage maps, technical reasons
for the site selection and a load of other similar information.
I am trying to clarify with the local council if they really do need
this form with the application or whether they are just practising
a tick-box methodology.


  1. Hi there,

    I found this blog after searching the internet for D-ATV projects. I'm working on a DVB-S/S2 modulator myself for a little hobby project. Contrary to a ground station, this is intended to be used in a mobile platform with limited space and weight constraints, although all the power is there that's needed.

    In post "Tuesday, 4 January 2011", you show a picture of an FPGA and DAC. You seem to be using them for text overlays and so on, not for modulation, right?

    Have you found any DVB-S fpga modulation cores on your searches around the internet?

  2. Hello Gerard,

    I seem to have lost my first reply to you.

    Yes I am using the FPGA to generate PAL signals.
    No I have not found any FPGA cores for DVB-S/S2 mainly as I have not searched for them.

    While DVB-S would be quite simple to do S2 is somewhat more difficult as it requires large lookup tables for the LDPC codes and has a deep interleaver 64000 bits. That would require a lot of extra memory. I did look into doing DVB-T2 on an FPGA but decided against it for those reasons (it neads even more memory).

    - Charles

  3. Hi there,

    Well, blogspot never sends replies, so I never got any notification that you responded. Sorry for replying back so late.

    Sounds like you're just using a standard PC/processor for this. What I'm mostly interested in is the ability to send data (2kB/s and up) and maybe even video if dimensions and weight allow it. Imagine a space-constrained R/C plane of up to 1.5 kg. The usual DVB modulators are just too heavy for this purpose. Do you think there are any designs that can meet these space constraints?

  4. Gerard,
    I don't know when people post comments either!
    I can't think of anything offhand, you could investigate digital CCTV or gut a cellphone that has a camera and use that to stream video or a WiFi video camera operating on 2.4 GHz, or just use analogue 2.4 Ghz