|K5JXH ,report . A single port Antenna network analyzer.
Sold by GIGAPARTS
All you need is a USB to RS232 adaptor bridge $4 and a metal box (Farady shielded is best for near field RF never a cigar box....)
With AntScope software. (free) ver1 and 2 both work great.
Other Hams program an Arduino, with LCD screen (shield) and some push button for portable and simple instant plots. (I will do that next)
The device is near genius design, the more you look deeper, wow. Nice. (the accuracy is astounding)
First off no China fake parts here, that killed dead my SARK . (In China they have parts that are not commerical grade, but are toy grade or down Binned parts for leakage and other reasons.) Avoid them.
I will show all tests done, including Antenna scans (VSWR) L, C, LC, LCR and TDR tests.
If you don't like the SMA small jacks, then put on an adapter of your choice. (I have SMA to PL259)
Using a dumb terminal program called "RealTerm" , sending command VER,(cr/lf ) it shows AA-30 ZERO 180
My first connection is here.
Click to zoom.
UART Dongle, (TTL232 actually) RS223 use +-12v data signal, this device uses, 5v.
Sold everywhere( w10 supports this directly PnP.) I like best the FTDI version. (windows 10 supports this 100%) OOBE.
Put the jumper on 5V not 3v. (I tested 5 top brands (chips) of UART and all 5 worked. (FTDI and Silicon Labs and others)
Wired ground to GND, +5v to +5v and TX2 to RX and RX2 to TX (that is called a crossover and is not optional) Jumper to 5v, not as shown above.
If the tool is dead seen my end of page help.
My first dual scan , the 2 antenna's 1 in the attic 35ft high a horz. G5RV and one vertical full wave Dipole. ZERO FIVE 33 foot
What great software, I hover on any point with the mouse and get full stats. wow !
Now a test jig, a RLC series tank circuit, ( C= 25530 / F x F x L) F, in MHz, L in uH, C in pF. ) 18 pF it is.
As we all know resonance is at Xc = XL point. (if you know R and L, you can compute for C or if know L, and R you can compute C easy.)
C= 165pF next to solve for L = 25530 / F x F x C = 6.7uH ( amazing close) lets compute or L. (all you need to know is Frequency and is 4.850 MHz.
One can use simple math to solve and unknow coil or cap value, if you know R and C you can computer L, or anything, knowing 2 of the 3.
My tank looks like this.
Test 3, just one, 13ft length of RG58 cable. One can also click TDR below and see the TDR end point.
One small improvement would be a GDT (Gas discharge tube) device, SURGE ARRESTER 75VV like the SARK100 has to protect this device. Bourns p/n# 2049-07-BLF 78cents at mouser.com (and $3.49 ship rate is nice)
I will put these parts in an aluminum BUD box, (Faraday) protecting it from NEAR FIELD RF , and use nylon standoffs, (form damage via near field RF and ESD zaps)
The TDR mode will find COAX transmission lines that are cut, kinked or crushed or water logged easy, TDR is R.A.D.A.R for wires, a very handy function.
I once found and open RADIO coax on an aircraft carrier , 1972 with a TDR (boat anchor sized) in compartment that did not exist on any drawing for the ship, the TDR showed the cut at 100meters. (amazing device it is)
(once found it was show and tell day for sure , compartment on ship full of rust (all bulkheads,overhead and deck)
A perfect transmission line is A flat 50 (z) ohms end to end, if you see wild Impedance changes in the distance axis, bingo damage , you have or a loss connector or rusty, (corrosion) or water logged, or kinks or crushed line.
In school they even demostrated , bad COAX on the TDR, a very amazing tool, but this tool (ANTscope2, does best only longer cables, up to 2100 feet, and the scale is fixed at that.
99.999% of dead tools is dead dongle.
Comms must not be dead. (I tested using USB 2, USB3 ports and even USB-C ) all work.
So lets test that dongle (UART ) first. (no comms no joy)
Below is port 4 38400, and port is open, and +CR must be set. CR means carrage return and if the tool fails to see CR it WILL not repond to any commands. (in "C" langauge this is ver/r/n (r mean return, n mean new line.)
If this fails, close the port and reopen it and it works, now. Make sure the PCs com port is set to 38400 BAUD in device manager, that matches the tool.
That is it for dongle testing. (easy as pie)