[600MRG] VNA S11 measurements, el cheapo junk box jewel...

[Dave Riley]

It must be getting winter cuz the solder pot is on.. This ends up being 
quite a fire in the belly hobby both going and coming with >70 years at 
it...
Great for a hobby/job, vote yes on making ham radio great again...

This poor man's SWR Junk Box Jewel is being replaced by a home brew VNA 
like box... N2PK++

OK, go gettem!!  and tnx for being here from daver aa1a


On 10/8/2018 7:29 PM, Dave Riley wrote:
> Am always looking for a value in the junk piles around here by picking 
> out some old dusty item to get some of em back in service as something 
> new but even useful...
>
> I guess we have all made some inroads as to MF antenna theory, feed 
> lines, and equipment etc...
>
> Then found a nice old clean Protek sweeper on e-bay that goes up to 2 
> mhz., then picked up a junked home brew swr bridge for re-issue, 
> thence to closest USB port for a fancy SWR look see about this litz 
> loop transmit antenna on 630 meters, sure tunes sharp...
>
> This is how it looks >>  Protek sweeper is putting out and centered on 
> 475 khz. to about 10khz wide, then dump this in to RF port, connect 
> the UNKNOWN RX coax to see a 630 meter litz loop.. Then the bridge 
> output is sent to the SDR receiver IN to see SWR return loss S11 like 
> spectrum...
> Using old sdr-iq receiver as a pan adapter scope and made them all go 
> like this  plug and play ;
>
> http://www.radiocom.net/600M/VNA1.png
> Is the noise floor of receiver tuned the 475 khz center
>
> http://www.radiocom.net/600M/VNA2.png
> Calibration open/short
>
> http://www.radiocom.net/600M/VNA3.png
> 50 ohm calibrated load
>
> http://www.radiocom.net/600M/VNA4.png
> Loop antenna feed point  @ center of scan with return loss across the 
> band, 10 khz. active window
> Indicates about -32 db return loss = about 1.05 SWR @475.670 khz.,  
> AA1A WSPR
>
> http://www.radiocom.net/600M/VNAsetup.jpg
>
> Another junk box jewel...  ( test equipment division )   What's in 
> your junk pile??
>
> Have fun!! 73s de DaveR aa1a
>
>
>