Posts

Showing posts from March, 2014

BladeRF, the transverter and HF TRX; it's been there all the time!

Image
BladeRF, the XB-200 transverter and HF TRX; it's been there all the time! The BladeRF and now its XB-200 transverter are very neat pieces of gear. Now the big "but" or "however".

Many people have been wanting to use the BladeRF on HF and were waiting for the transverter to be delivered in anticipation of it covering HF. However, the original range of the transverter was 30 to 300 MHz, with no apparent coverage. When the final design and photos were released, coverage was 60 kHz to 300 MHz, which no doubt pleased many people.

I went though the schematics trying to find the modifications to cover HF, but they were not apparent, a point I raised in the Nuand forum. I received a reply from Nuand to say that the HF access was not very obvious and went to the ADC/DAC. This mystified me for a few days until it finally clicked on how HF is done, which is exactly what they way they said. However HF TRX is virtually independent of the transverter and could have been use…

Red Pitaya: arrived and working

Image
Red Pitaya: arrived and working My Red Pitaya has arrived and was working with a minimum of fuss. Simply type in the device's unique MAC address on the connect page http://discovery.redpitaya.com/ and hit connect.

The instrument functions are web applications. Just click which instrument you want and it comes up in a web page. I was curious how they could get it to work on any computer, tablet or operating system, but the web access is the answer. I am not sure what consequences that has for performance, but it works and it is still early days.



The Red Pipaya connected to give some idea of size. It gets pretty hot, maybe too hot for a warm climate like northern Australia; we shall see. The device is working as an oscilloscope and signal generator, with an output connected to an input.


A sine wave at 20 MHz. Many of the adjustments are manual and take a bit of getting used to. However, it works. Not the cleanest sine wave; not sure if it is the signal generator or oscilloscope. La…

HiDes CCHDTV camera and DVB-T modulator DC-100 Full HD 1080P

Image
HiDes CCHDTV camera and DVB-T modulator DC-100 (preliminary)
I received a HiDes DC-100 (US$250 for camera, $100 for lens) last week but did not have much time to set it up, other than to verify it works.

With a bit more time tonight I have a very nice Full HD image from it.


The lighting was bad, but a still a good clear image. The DC-100 transmits both a SD and HD channels as can be seen in the channel list. The camera is running on its default setting of 177 MHz, 6 MHz bandwidth, but over a cable with an attenuator. The image is 1080P 30 FPS. As a result there is some flicker from the 50 Hz lights.

I will put up some photos of the device and its internals later.

CCHDTV is an emerging standard of DVB-T cameras designed to run on existing coaxial systems in buildings and institutions. The devices all seem to be based on the ITE modulator chips. Google CCHDTV for more information.

The DC-100 uses a standard CCTV SDI camera, either 2 or 5 Megapixel, the converts the raw SDI stream to DV…