[CQ-Contest] Slick New Toy

[Jim Brown]

Here's another nice new toy from DL-land by way of the UK. The designer 
is DG5MK. SDR-Kits is some hams in the UK that build and sell the 
excellent DG8SAQ VNWA Vector Network analyzer and provide great support.

https://www.sdr-kits.net/VA5_Page

$235 got the analyzer and a "better quality" cal kit shipped to my door 
just before CQWWCW. The better Cal kit was $20 of that cost.  I found 
time to build it on Wednesday -- It took less than two hours to put it 
together (as I get older I get slower). It's a single-port true vector 
analyzer, and runs either stand alone on two internal AAs or from VNWA 
software via a USB port. Decent build quality, the BNC is soldered to 
the board and bonded to the case at the point of entry. The case is a 
2-piece metal clamshell, screwed together at four places. In other 
words, it's well shielded and has no Pin One Problem!

There's a beautifully printed manual that covers building and operation, 
with excellent color photos. Text is excellent in the building section, 
pretty good in the button-pushing area, a bit weak in the concepts area, 
and badly disjointed to point of being awful in its description of 
calibration. The latter is a big deal, because it's the first thing you 
do once you turn it on!

As near as I can tell,when running from VNWA software (FREEWARE), it can 
do almost everything the VNWA can do with S11 (single-port) 
measurements, except that choices of sweep rates and dwell time at each 
data point are a lot more limited. That means I can use the excellent 
TDR function built into the VNWA software! I don't know yet if I can 
import complex data made stand-alone. BTW -- the measurement plane is at 
the end of a 5 ft piece of RG142 from my stash. I find that a convenient 
length for getting to where I can measure antennas from my shack.

This box is designed to be the stand-alone unit you use in the field and 
at the top of the tower with no computer, but with the VNWA software 
conneccted via a USB port, you can make measurements in the shack, 
including TDR, then export antenna data to SimSmith to transform it to 
the antenna ffeedpoint, then use SimSmith to design matching networks 
and compute  loss in the feedline and matching networks!

This is a VERY nice unit, and a real bargain!

73, Jim K9YC