[TowerTalk] Slick New Toy

[Jim Brown]

Here's another nice new toy from DL-land by way of the UK. The designer 
is DG5MK.

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. 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, 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 one you use in the field and at the top 
of the tower, but with the VNWA software, 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