Thursday, January 13, 2011
I acquired a USRP N210 in December and love it. I was using an old Pro-2022 as my IF but it has alot of freq gaps, cant be controlled with the pc, plus other issues.
So I bought a PCR-100 off eBay for cheap and proceeded to read the service manual for it which can easily be found online. The service manual labels the parts really well, although my pcb rev is slightly different then the one in the manual its close enough.
I chose a spot right after the 2nd IF, right past a cap. Your going to need a cap anyways to filter the DC out, plus it had a through hole to make it easy to solder a wire too. (I see now radioreference.com recommends the same spot hehe)
Now if your only interested in 230khz of bandwidth (ie a softrock which has 192khz bw) then you may want to consider choosing farther down the line. Past the point I chose it goes to a NBFM or WBFM filter, then to another IF amp. You may want to choose that IF amp as a tap point, but I wanted alot more bw then that, I wanted to get as much as I possibly could from the Icom unit. Plus Ive got a IF buffer amp from Clifton Labs I will be eventually putting inline, so the extra gain isnt that important to me.
I took pictures as I went along, you can download them in high res here
As a note, I use qpcr1k in linux to control the PCR-100, which works well over X11 forwarding so my mac has access to it as well. I use gnuradio companion (grc) for the USRP N210. That USRP w/Gnuradio is an amazing combination, one heck of a SDR.
edit: 05 March 2011
Ive uploaded my Simple PCR app, all it does it turn the device on/off and tune a freq
edit the .py file to set your /dev/ttyUSB# or /dev/ttyS# your using to connect the computer to the pcr with