[amsat-bb] Yaesu FT-857D

Fri Jan 22 20:08:49 UTC 2016

Hi!

I have been using SDR receivers as part of my satellite work
for a little while now, and have used (or tried to use) a
few of them...

"RTL-SDR" dongles (the $20 or so dongles)
FUNcube Dongle Pro (original version)
FUNcube Dongle Pro+ (current version)
SDRplay
HackRF (One and Blue versions)

The RTL-type dongles and the FUNcube Dongle Pro (not the
Pro+) lack front-end filtering, which rendered them useless
when I tried to transmit with either an HT or FT-817 in
close proximity - even with there was a diplexer in front
of the SDR devices. These devices would basically shut down
until I ended my transmissions, when they would resume working.
The newer R820T2 type of the RTL dongles may have better
stability, but they all seem to lack front-end filtering that
would be desired when working our satellites.

The FUNcube Dongle Pro+ and SDRplay work well as the downlink
receiver when I have worked satellites. These devices cost
more than the RTL-SDR dongles, but they come with front-end
filtering that helps greatly when they operate near your
uplink transmitter. I have had success with both of these
devices, along with HDSDR (the Windows software I prefer to
use when working satellites with SDR receivers) running on
a laptop or small Windows 8.1/10 tablet. I currently prefer
to use the SDRplay as my downlink receiver when I am working
satellites, but will occasionally use the FUNcube Dongle Pro+
from time to time. The SDRplay currently retails at US$ 149
from either HRO stores or the www.sdrplay.com web site located
in the UK. The FUNcube Dongle Pro+ costs around US$ 190 to
US$ 200 including FedEx shipping from the UK, depending on the
exchange rate.

The FUNcube Dongle Pro+ is supported by the FUNcube Dashboard
software for FUNcube satellites like AO-73, and the FoxTelem
software for AO-85 and the upcoming Fox-1 satellites. If I use
my SDRplay to decode telemetry, I would need to pipe the
received audio through a virtual audio cable into those
programs before telemetry can be decoded by either of those
programs.

I have both the commercially-made HackRF One and the crowd-
funded HackRF Blue devices. These are broadband transceivers
that are capable of receiving at bandwidths up to 20 MHz. I
have not tried using either of these when working satellites,
mainly due to the lack of front-end filtering in these devices.
HDSDR only supports using a HackRF device as a receiver, and
I have not tried using either of these as a transmitter. The
HackRF devices are capable of transmitting at low-milliwatt
ranges across the spectrum they cover (officially 1 MHz to 6
GHz, but many have been able to lower the low end of that range
to 100 kHz or so). The HackRF One retails at around US$ 300,
depending on which reseller you buy from.

My recommendation would be to go either with a FUNcube Dongle
Pro+ or SDRplay. Both are in the same price range, and work
well as part of a station for working our satellites. These
may cost a lot more than the cheap RTL-SDR dongles, but it
is better to know the limitations of the low-end devices up
front, instead of getting frustrated with them later on. The
cheaper dongles can work well for receive-only applications,
provided you are not near strong sources of RF (including
your own transmissions), but I think the FUNcube Dongle Pro+
or SDRplay would work well alongside the original poster's
FT-857.

Now if there was a software-defined transceiver capable of
working our satellites full-duplex, without the need for
upconverters/downconverters/transverters to cover 2m and 70cm,
I'd be interested. Until then, I am OK with using an FT-817
(or similar radio) with an SDR receiver and software running
on a tablet. I wrote articles about using these SDR devices
with Windows tablets that ran in the AMSAT Journal and
AMSAT-UK's OSCAR News in the past year. Those articles are
available in PDFs from my Dropbox space:

http://dropbox.wd9ewk.net/

(go to the Articles folder, then look for the files with SDR
in the file names)

73!

Patrick WD9EWK/VA7EWK
http://www.wd9ewk.net/
Twitter: @WD9EWK

On Fri, Jan 22, 2016 at 12:10 PM, John Toscano <tosca005 at umn.edu> wrote:

> Mentioning that you are waiting for a tax refund makes me think you are
> planning to dive into SDR with a fairly high-end and expensive unit, You
> can probably get away with spending $25 or so if you have reasonably modest
> expectations. Noo Elec makes a whole line of SDR devices, from inexpensive
> dongles to the pricier (but well worth it if you have the passion) HackRF
> unit. Take a look here:
>   http://www.nooelec.com/store/sdr.html
>
> There are some dongle vendors who sell junk. the Noo Elec units are high
> quality. Of course, take that recommendation from someone who owns one of
> their dongles, plus HackRF Blue board (clone of the HackRF and virtually
> unobtainable now), and a Flex-1500.
> ;^)
> 73 de W0JT/5, EL09vu
>
>