Sdr newbie question

[KB8VIV]

Hey everyone, I stumbled upon this video and started thinking tha this would work with my ts-870, as it has an i.f. Out (at 8.83, via an rca connector).  I downloaded the isdr app on my ipad, and it appears that all i'd have to do is get the camera kit, and the griffin i-mic.

My question is, am I feeding the if out into the i-mic, or audio from the rcvr?  Anyway, here's the video:

http://www.youtube.com/watch?v=qUHbPZztkiY

I notice that there arent many options to get the spectrum display for my imac, so this may be the next best thing.

Thanks for any advice.

Kb8viv

[PJ2BVU]

It looks like you have much reading to do on SDR.
If you want to use you IF out you would have to use something like the P-PAN to get the I/Q outputs and have a spectrum display as wide as your IF is.
I had an extremely quick look at iSDR and you can connect the audio output of your rig to your iPad but in this case it won't be SDR but audio DSP processing and you won't see much spectrum as the bandwidth will be limited by the filters of your rig (something like 2.4kHz = one SSB station).

Jean-Claude PJ2BVU

[K8AC]

To elaborate a bit on what Jean-Claude said: The signal coming out of the TS-870 IF out jack is an RF signal with a center frequency of 8.83 MHz.  The IQ signal coming out of the transceiver in the video is an audio frequency.  To connect the output of the TS-870 IF to the sound card input, you first have to convert the IF signal to a baseband audio signal with the necessary IQ output.  One way to do that is with an N8LP LP-Pan unit, properly configured for the 8.83 MHz RF input.  The output of that unit would have the necessary I and Q signals for input to the stereo sound card. 

I have no idea where the IF tap is done in the TS-870, but if it's before the filters, then you should be able to see some reasonable portion of the band on the panadaptor screen, but probably NOT the full bandwidth that the sound card would support.  The sound card I use supports a 192 KHz bandwidth and my transceiver IF tap provides that much bandwidth so I can see a wide portion of the band at one time.

The LP-Pan unit will cost you over $200.  There are other approaches than LP-Pan - some guys use a Softrock receiver (very inexpensive) and there are a variety of other more expensive SDR receivers that could be used.  The LP-Pan was created for this very purpose and is the best solution in my opinion.  The bandwidth seen on the panadaptor also depends on the sound card used, and few will provide the full 192 KHz. 

73, Floyd - K8AC

[KB8VIV]

Hi Everyone,

Thanks for all the replies, this answers a lot of my questions.

Steve