Stefan
If you need more dynamic range
This was a thread on the other mf
group , when the possibility of direct-sampling
was first announced , but then, only for lynux
based systems, using a 24 bit
instrument A/D convertor
Up to now, no such device has been tested ,
but it would offer a solution to the 'large
signal ' problem , with 100 dB dynamic range , the chips
are £7 on ebay . or there is
a AD7760 Evaluation Board
| Model |
Price |
| EVAL-AD7760EDZ Status: Production |
$59.00
|
Cypress FX2 usb board's , round $10 ,
so that's , $70 for a top level
MF rx ?
Just need some one , who is
conversant with hooking these things
together ! Alberto has all ready offered to write
the DLL !
Any one ?
73-G..
Re: [rsgb_lf_group] SDR 0..1MHz
Thinking about an SDR receiver meant for the
0..1 MHz band, a possible,
minimal hardware-wise realization could perhaps
be that of using an Analogue
Devices AD-7760 ADC, with its superb SNR,
sampling at 2.5 MHz, 24 bits,
followed by a Cypress FX2 chip to implement a
USB dialog with the PC.
No FPGA nor DDC would be needed. The
hardware would then send
a 2.5 MHz stream of digitized data to the PC, which
will process them
with, e.g. Winrad. Winrad is quite
capable of coping with such data rate.
In this very moment I am listening
with Winrad and the Elad FDM-S1
receiver to a local MW station, and the
FDM-S1 is set for a final output
frequency (after its DDC) of 3072 kHz.
So 2.5 MHz would be a breeze for
Winrad.
If somebody designs and
builds such a hardware, I am more than willing to
write an ExtIO DLL to
interface Winrad with it.
73 Alberto I2PHD
Sent: Friday, April 05, 2013 8:57 AM
Subject: LF: Dongel-SDR on LF?
Thanks to all for the advice. Now i have the necessary
informations to start some tests.
Has someone tried such a stick on 137
kHz? What is the dynamic range? You know, the DCF-39 problem... I.e. 60 dB would
be problematic here...
73, Stefan/DK7FC
Am 04.04.2013 21:08,
schrieb Graham:
Same stick Stefan
The layout is uff/vhf down
convertor feeding 28 MHz
A/D , every one started
using HF to VHF convertors , but they have
a problem as the off set qrg
approaches 'zero' in the oscillator
starts to leak into the signal path
At first there was very little
code data on the chips , but some
one managed to get the command listings and now
, can turn the down-mixer off or
make it idle - and with connecting
directly to the a/d , you now
have a HF radio
you need to google to buy
or for drivers etc ...
main chip set for dongle >>
RTL2832U +
E4000 Amazon , etc but some of
the prices are now a bit silly ,
some of the HongKong sellers are adding
plugs and software
HDSDR
SDRSHARP
This is the dongle I modified for HF
, you can see C2 , linked to pin 1 of
the A/D , just connect to that ( if it was
a one way mod , you could remove the
cap to isolate the a/d)
Good luck ! if it go's bang ,
then its £10 wasted , not $1000
!
73-G.
