Call Search
     

New to Ham Radio?
My Profile

Community
Articles
Forums
News
Reviews
Friends Remembered
Strays
Survey Question

Operating
Contesting
DX Cluster Spots
Propagation

Resources
Calendar
Classifieds
Ham Exams
Ham Links
List Archives
News Articles
Product Reviews
QSL Managers

Site Info
eHam Help (FAQ)
Support the site
The eHam Team
Advertising Info
Vision Statement
About eHam.net

   Home   Help Search  
Pages: [1]   Go Down
  Print  
Author Topic: Sdr newbie question  (Read 2279 times)
KB8VIV
Member

Posts: 47




Ignore
« on: February 26, 2013, 07:17:52 PM »

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
Logged
PJ2BVU
Member

Posts: 111




Ignore
« Reply #1 on: February 26, 2013, 08:52:21 PM »

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
Logged
K8AC
Member

Posts: 1465




Ignore
« Reply #2 on: March 04, 2013, 06:22:43 AM »

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
Logged
KB8VIV
Member

Posts: 47




Ignore
« Reply #3 on: March 04, 2013, 08:24:37 AM »

Hi Everyone,

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

Steve
Logged
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC Valid XHTML 1.0! Valid CSS!