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KC2UGV
09-19-2013, 06:55 AM
http://pe1nnz.nl.eu.org/2013/05/direct-ssb-generation-on-pll.html

http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter

I've tested the FM transmitter on 2M, and it works well (enough). It's about 1W out, so in reality, using it on broadcast FM band is likely illegal. I haven't had a chance to test the SSB generation yet, however prospects are looking good.

There are also projects that can enable it to receive using a TV dongle: http://zr6aic.blogspot.com/2013/02/setting-up-my-raspberry-pi-as-sdr-server.html

For under $100, and some elbow grease, you have an entire SDR QRP rig at your disposal here.
mw0uzo
09-19-2013, 11:55 AM
That is excellent!! :rock:
And no need for any extra DDS modules, how good is that!!
NQ6U
09-19-2013, 12:27 PM
Very cool! Been looking for an inexpensive QRP SSB rig for a while now, this fits the bill perfectly.
W3WN
09-19-2013, 12:38 PM
Keep us posted.

I have a 40 M SDR receiver, one of the SoftRock units. I need to get back to my RPi, get that configured, and then get the SoftRock working. Adding a transmitter to the mix? Perfect.
wa6mhz
09-19-2013, 02:47 PM
Great! Now that I have a Raspberry Pi, I have been looking for a use for it. But not very informed on the programming part of it all. That looks kinda tough.
N8YX
09-25-2013, 08:31 AM
Interesting.

As far as programming is concerned, how would an Island code repository go over with everyone? We could all contribute a bit to various flavors...
KC2UGV
09-25-2013, 09:51 AM
Speaking with Kelli, IRL, she had mentioned this would need a high pass filter, due to the harmonics generated by a square wave (Digital out, being what it is), but no biggie. Now, I'm working on building one (In addition to the other many things I'm working on).

And, my estimate of 1W might have been a bit generous. My last test had the signal die out about 1/2 mile from the house (Over VHF). Not sure if the power curve is linear or not, that will be my next test.
NQ6U
09-25-2013, 11:27 AM
Speaking with Kelli, IRL, she had mentioned this would need a high pass filter, due to the harmonics generated by a square wave (Digital out, being what it is)...

Wouldn't that be a low pass filter? Or am I missing something?


As far as programming is concerned, how would an Island code repository go over with everyone? We could all contribute a bit to various flavors...

Well, not all of us...
KC2UGV
09-25-2013, 11:47 AM
Wouldn't that be a low pass filter? Or am I missing something?


Could be what she said.
n6hcm
09-26-2013, 02:37 AM
i'm afraid of raspberry pi. they're so cheap that they could end up all over the house ...
KC2UGV
09-26-2013, 06:13 AM
i'm afraid of raspberry pi. they're so cheap that they could end up all over the house ...

I've already slotted to buy two more: One to run XBMC (Media center distro), and one RetroPi (Retro gaming console). Maybe another to act as a NAS. And another for...
W3WN
09-26-2013, 07:55 AM
Hmmm. Hadn't thought about one to run a NAS. Definitely want to hear more about how you plan to do that.

Video cable came yesterday afternoon (yea!). Sometime this morning, I'm going to raid the box of Blackberry's for a wall wart, and then assembly comes after lunch (pending work related projects, of course)
KC2UGV
09-26-2013, 08:23 AM
http://lifehacker.com/5988835/turn-a-raspberry-pi-into-a-low-power-nas

Performance wont be on par with, say, a dedicated NAS with SATA backplanes, but it will do for most home applications, such as backup, documents, pictures, etc etc. Might not be so great for streaming movies.
wa6mhz
09-26-2013, 11:02 AM
I've got mine up and running now.
http://forums.qrz.com/showthread.php?405902-Raspberry-PI-for-Ham-Radio/page4

Also got the USB audio dongle so that will be great for PSK/RTTY. Have yet to see if that works for it. Like the idea of a TINY PSK31 station. The keyboard and mouse & monitor take up more room than a NETBOOK though. need to find an ULtra-Micro Keyboard and monitor.
W3WN
09-26-2013, 11:10 AM
Mine is up as of about 2 hours ago as well.

Biggest problem? Getting the damn plastic case open! Once that was done, everything snapped into place (no screwdrivers, golden or otherwise, were harmed in the assembly of this Pi), connected it up to the Viewsonic monitor, plugged in a Blackberry wall wart, and voila!

I have a USB splitter/adapter for keyboard & mouse, which it recognized, so I'm only using one USB port for those. Haven't put it on the network yet.

Cute little sucker, isn't it?
N2CHX
09-28-2013, 07:34 AM
Could be what she said.

Low pass filter is what I said lol.