<div dir="ltr"><div>If anyone is interested I have Software Defined Radio for sale on Ebay at the moment. I've used the same type of unit to run a DAB test multiplex. I'm pretty sure I've recall that someone has already written the code to run it as a DRM transmitter.<br><br><a href="http://www.ebay.co.uk/itm/HackRF-One-Software-Defined-Radio-NEW-Unopened-FREE-Postage-BARGAIN-/271983417851?hash=item3f537999fb">http://www.ebay.co.uk/itm/HackRF-One-Software-Defined-Radio-NEW-Unopened-FREE-Postage-BARGAIN-/271983417851?hash=item3f537999fb</a><br><br></div><div>I can't help feeling though that the SDR is the "easy" part. The difficult part is getting an efficient aerial system.<br><br></div>Glyn<br><div><div><br>-- <br><div class="gmail_signature">Glyn Roylance - Principal Consultant
<div>
<div><a href="http://www.a-bc.co.uk/" target="_blank">Associated Broadcast Consultants</a></div></div>
<div> </div></div><br><br><br><br><br><div class="gmail_extra"><br><div class="gmail_quote">On 15 September 2015 at 08:16, Tony Bailey <span dir="ltr"><<a href="mailto:ravensound@pilgrimsound.co.uk" target="_blank">ravensound@pilgrimsound.co.uk</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000">
<div>Hello Marc et al,<br>
<br>
I mentioned DRM on AM because it would be easily implemented in a
software box. I think the Talk 107 test used two programme
channels on one FM carrier. In fact the main issue with medium
wave is getting a stable earth system without ploughing a field!
Antennas can be short (most RSLs use them) but they aren't very
efficient due to being very small impedance compared to the
ground. As has been pointed out this isn't a problem if you can
site the antenna in (or on) water. I wondered if given that SDR
requires an rf box maybe a clever designer could come up with a
low impedance amp that could include matching directly connected
to the vertical antenna sitting on a ground plane.<br>
<br>
Regards, Tony<div><div class="h5"><br>
<br></div></div></div></div></blockquote></div><br clear="all"><br><br></div></div></div></div>