Softrock still works!
[ No Comments ] Posted on 07.08.10 in Amateur Radio, SoftRock
I pulled the old softrock rxtx v6.3 out of storage last night and managed to get it working with a string antenna. This thing still amazes me on how sensitive it can be considering I was just using a few feet of random wire inside at ground level. I used Sebastian Mrozek’s software DSP Radio on my mac which is pretty slick but underdeveloped. It has a lot of potential but I haven’t seen an update for a while and I start to doubt it will be. I also found that the audio quality was much better when using my EMU 0202 USB sound card.
I didn’t try transmitting since I don’t have a decent antenna system and don’t want to hurt the PA circuit. I might have to try and construct some sort of simple wire dipole inside my lair. Alas I am without a windows machine so no Rocky for me (Rocky is a pretty ice simple piece of software to run a softrock with, but it doesn’t work under wine) so I can’t use PSK and my morse code is not up to scratch for a QSO so I dunno who I would talk to anyway. Plus, I am waiting on a keyer from MJF which they seem to be taking forever to supply.
OK – enough rambling…
Upgrades to Blog
[ No Comments ] Posted on 11.19.09 in Blog/News, CW Morse Code, SoftRock
Well things have been busy. I landed a job in Boston which means I have been busy finishing up work at my current location. Moving is annoying so I have been rethinking the amount of computer gear I have. This means I have been migrating all my web stuff onto the one machine. It’s all there now – I should say it’s all _here_ now.
I have been working on the softrock radio as well. I built the USB interface and have been making some contacts with PSK and one (poorly) attempted one on CW using a paddle through the USB interface. It all works very nicely!
Now I just need to amp up the 1 watt out from the softrock into something more like 10 watts. That would be nice…. working on that now, $$$ permitting. This might have to wait until after the move to Boston.
Softrock works!
[ 1 Comment ] Posted on 08.27.09 in Amateur Radio, Home Brew, SoftRock, Uncategorized
It works!
Below is the build, essentially done. I need to better connect audio in and out. And I need to consider if I will add the DB9 serial connector. Marvel at the beauty of the Softrock TXRX V6.3 below.
And did I mention, it works!? Below I have it operating on the 40M band – tuned to W1AW at 7047.5 kHz. The software is Rocky. Rocky has a nice “auto IQ Balance” function which I had a bit of trouble getting to work nicely with an EMU 0202 USB sound card. I had the input volumes turned up quite high which seems to be a mistake. I tuned them way down and the software corrected itself very fast after that. I have absolutely no mirror images that I can see at all. Any images would have to be down at least 50-60 dB for me not to notice them.
The inbuilt sound card in my Macbook Pro does a pretty good job as well, but the EMU 0202 is an improvement. I’ll have to take some screen shots and compare them more systematically.
I did get a chance to transmit as well. I found I could get rid of the mirror images easily with the TX IQ Balance in Rocky. The mirror image was down at least 50 db after balancing. I have no idea what power output I have. I need to work on this a little more.
Problems and Concerns:
- The EMU 0202 sound card can sample at 192 kHz, but Rocky can not work at this frequency. Annoying!
- I suck at construction. I keep getting worn joints with the audio in/out and I’m wearing out the sockets.
- I really wanted to get this to work with my ASUS 901H Netbook, but it is really too slow to work at high sampling bandwidth. Also, the standard soundcard inside the netbook is terrible. Resorting to the EMU 0202 works, but sound out is choppy at times.
- The Local Oscillator Frequency is quite strong and radiates as well. I will measure just how much is radiated compared to a CW signal and it’s mirror image, soon.
In all, I’m very happy to have this project working. It is a bit ugly in places – I need to develop of construction skills a bit – but it has been a lot of fun. I should have it cased up soon and be ready to put into operation in the field soon. I should be upgrading to general license soon too (maybe extra as well) so I will be able to use this radio alone legally soon too.
SoftRock RXTX V6.3 Buiding
[ No Comments ] Posted on 07.17.09 in Amateur Radio, Home Brew, SoftRock, Soldering
I have been slowly building a SoftRock transceiver, which as it turns out is a bigger project than I thought it would be. Having said that, it has been great fun.
The Softrock family of kits are all centered around the SiLabs SI570 chip, a programmable oscillator, that is clocked at 4 times the center frequency required in order to generate I and Q (90 degree phase shifted) signals for mixing with received rf and passing onto a computer which acts as a software designed radio. This is of course the latest and greatest thing in radio and the SoftRock Kits are exploiting this technology cheaply and making it available to the hobbyist to build themselves. If you want to know more, check out the SoftRock page or read up on Software Defined Radio.
Only problem is the soldering of the chip!!! Check out the image below.
That’s right, surface mount is the go here, but not only surface mount, it is pinless! The chi is pinless!!! I have never done this before, but I have so far managed to solder the sucker in place and once under the command of a pic chip that programs its frequency in, it oscillates quite nicely (at 4 times the needed frequency).
The kit I am working on has a transmitter stage too, so it is a full transceiver. I will post more on it as I build more. I just wanted to show off my soldering of a pinless IC. Still can’t believe it works.