Help on choice of daughter board for 40-50MHz experiments

GNU Radio
1

Hello ,

We are looking for a daughterboard to run experiments within the range
of 40-50MHz. We have used the basic Tx and basic Rx before but just for
routing signals to an oscilloscope probe. Has anyone got any experience
with actual transmission and receiving with the basic TX/RX boards? We
have not tested yet because we are yet to purchase LF antennae. Any
experience with these will be of much help.

Respectfully,
H. E. Baidoo-Williams,
GRA, University of Iowa

2

On Mon, Oct 8, 2012 at 11:54 AM, Baidoo-Williams, Henry E
[email protected] wrote:

We are looking for a daughterboard to run experiments within the range of
40-50MHz. We have used the basic Tx and basic Rx before but just for routing
signals to an oscilloscope probe. Has anyone got any experience with actual
transmission and receiving with the basic TX/RX boards? We have not tested
yet because we are yet to purchase LF antennae. Any experience with these
will be of much help.

You can use the Basic RX and TX for those frequencies. You will
probably want to put filters between the antenna and the boards for
your specific frequencies of interest.

Matt

3

probably want to put filters between the antenna and the boards for
your specific frequencies of interest.

Matt

I’ll add “and some gain”.

I use a BASIC_RX on a USRP2 (same sample rate as the N2XX) for a
riometer operating between 25MHz and 45MHz. For the project, we
built a custom filter board with distributed gain and
filtering–doing so helps with any possible aliasing problems, and helps
with
sensitivity.

–
Marcus L.
Principal Investigator
Shirleys Bay Radio Astronomy Consortium

4

Hello ,

Thanks a lot Marcus and Matt. Marcus, can you please share the
schematics of your custom filter board with distributed gain and
filtering? That will be of much help and we can easily incorporate it
knowing there are no bugs. And can you help us with the antenna you are
using? I called ettus and they don’t have any antenna to go with the
basix RX/TX and they have no recommendations also. Can anyone help.

Respectfully,
H. E. Baidoo-Williams,
GRA, University of Iowa

5

On 10 Oct 2012 11:40, Baidoo-Williams, Henry E wrote:

Hello ,

Thanks a lot Marcus and Matt. Marcus, can you please share the
schematics of your custom filter board with distributed gain and
filtering? That will be of much help and we can easily incorporate it
knowing there are no bugs. And can you help us with the antenna you are
using? I called ettus and they don’t have any antenna to go with the
basix RX/TX and they have no recommendations also. Can anyone help.

Respectfully,

H. E. Baidoo-Williams,
GRA, University of Iowa

I
can’t share the schematics, it was part of a contract I did for a
scientific instrument company.

I used a cross-dipole antenna designed
for the frequency range of interest, and designed to project a
largely-circular pattern on the sky overhead.

The type of antenna you
need depends heavily on your application, and there are a lot of
antenna companies out there that can meet various needs. The antenna we
used was custom-built.

You might look at the research done by these
folks, and the low-frequency radio astronomy folks in general:
http://www.ece.vt.edu/swe/eta/

But, it really depends on your
application.

Cushcrafts makes a “Ringo Ranger” antenna – there’s a
6-meter and 10-meter version, and they can both be tuned fairly widely
– I used a 6M Ringo Ranger for meteor studies earlier this year,
re-tuned it for TV channel 4.