[Elecraft] Digitized IF over IP?

Fred Jensen k6dgw at foothill.net
Tue Nov 21 22:45:42 EST 2017


Yes, 1st IF normally feeds a P3 at around 8 MHz thru a short length of 
RG-58.

Yes, the BW at the 1st IF is quite wide, limited only by the front end 
BPF.  After down conversion to baseband [or something close, 15 KHz 
comes to mind [:-)] it would need bandlimiting before the ADC.  That's 
not at all unheard of.  50 KHz BW would be fine with me, I'd settle for 
20 KHz.

Yes, I know where the roofing filters are and they're not relevant here, 
the P3 sees the signal chain before them in a local environment.

The P3, in a purely local environment, has access to the K3 via the CAT 
port which tells it where VFO A and B are tuned, thus permitting Fixed 
Tune mode where the P3 cursor follows the "Big Knob."  That would be 
really cool in the remote environment.

There are many non-P3 solutions here ... I have a P3 ... first plan 
would be to get it to work remotely.  I will try running the K3 CAT port 
thru the P3 to the RRC-1258 and see if that still works remotely and 
what the P3 does with all the Microbit chatter on the cable.

Lots of good info and ideas coming out of this.  Thanks to all

73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 11/21/2017 2:20 AM, Edward R Cole wrote:
> I"m not sure what bw you are requiring for IP, but I assume you are 
> talking about the 1st IF of the K3 or K3s.
>
> You do realize that its very wideband at that point.  Roofing filters 
> follow the 1st IF to feed the 2nd IF and DSP ckts.  I run two LP-Pan 
> from the IF of both my main and subRx on the K3.  Input bw of the 
> LP-Pan is 400-KHz and can provide 196-KHz IQ baseband output.  I also 
> have a SDR-IQ with max bw of 190-KHz.  I only utilize that bw when 
> measuring sun noise on 1296; normal bandpass for monitoring is 100-KHz 
> which covers eme sub-bands.  For MAP65 I only monitor 60-KHz 
> (144.095-144.155 MHz); Map65 takes output of two LP-Pan into a Delta44 
> soundcard which has 96 KHz bw.  My emu0202 can do 196 KHz but run from 
> K3 audio out its limited to 4-KHz bw.
>
> I would guess the 1st IF would receive bw of a complete band (28-30 
> MHz on 10m).
>
> 73, Ed - KL7UW
>   http://www.kl7uw.com
> Dubus-NA Business mail:
>   dubususa at gmail.com



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