Re: [Discuss-gnuradio] Multiplexing modulators

[Iain Young, G7III]

Hey John,

On 24/06/11 15:06, John Ackermann N8UR wrote:
> Marcus D. Leech said the following on 06/21/2011 07:54 PM:
> 
>> I have an example, in GRC, attached.
>>
>> It uses an audio source, which is common to all three modulators, this
>> goes to a fractional interpolator to interpolate up to the basic
>> sample rate of 200Ksps, which is an integral divisor of 100Msps.
> 
> After a couple of days away, I'm able to get back to this.  Thanks very
> much, Marcus, for the example.  It perfectly shows how to do what I want
> -- it's amazing how a block diagram coupled with a very few words can
> explain a concept.  GRC is a wonderful thing!
> 
> The project might be of some interest to the ham radio folks in the
> group.  I thought it would be a very neat demo of SDR capabilities to
> program a multi-channel repeater using USRP.  The final version will
> have 4 NBFM input channels on the 2m ham band, mapped to 4 NBFM output
> channels on the 70cm band (going crossband hugely simplifies the RF
> plumbing issues).

I'd be very interested - esp if you are planning on doing it in GRC.

I've been toying with a two-way ("Talk-Thru") version myself (IE listen
on 2 and 70, (re)transmit on 2 when we get a carrier on 70, and vice
versa) for RAYNET use


73s

Iain