N1201SA/N1201SA+ Antenna Analyzer discussion


#1

I’ve seen mentions about this analyzer on a couple of threads, how about creating a dedicated thread to it?

Mine arrived today from Banggood. Took 10 days to process and another 30 days to arrive (Brazil).

Paid 142.40 shipped

It would be nice to post some proven antenna designs,cables lengths and connectors

On this blog afu-nord.de/n1201sa-2/ (in german) DJ3LE compares it agains an Agilent 8714ET professional RF Network analyzer

Results are very impressive, it shows exactly the same results.

Agilent

N1201SA

English Manual
(https://youtu.be/d-fse1jCJ8U)


#2

Thanks aldoir, good idea to create new thread dedicated to Analyzer N1201SA.
Amazing to see this $140 analyzer gives same results as a $25,000 ~ $35,000 analyzer gave.

I have already discussed about NA1201SA, and posted test results for different antennas in following threads:

Off Designed-Frequency Behavior of 2 Types of Antennas

measuring antenna performance?

Waiting for others to post their test results in this new thread created by aldoir.


#3

@aldoir
Did you test your J-Pole and Super J-Pole? Waiting for you to post results.


#4

Okay, you’ve provoked me into ordering one.

There’s a lot of BIG differences between these little beasties and a real spectrum - network analyzer.

One of those big differences is using a tuned, selective receiver for making measurements. These little beasties are a DDS signal source and a very wideband detector. In such a system, energy entering the receiver at other frequencies (such as your local cell phone tower or nearby DTV station) is going to affect the measurements you’re trying to make.

Still, it’s better than a poke with a stick, and if you understand its limitations, it’s going to be an interesting toy.

bob k6rtm


#5

Not yet, today I took a time to make proper test cables (realized that my test cable had a bad contact :open_mouth:) and started to play with a FA antenna-clone (1/4 sleeve + 5/8) but ran out of time, but be sure I’ll test every single antenna I can make =)

@k6rtm for a hobbist it’s like taking a blindfold off, it’s fantastic to see what you’re doing.


#6

I’m not sure how these analyzers will test antenna performance. They will test various parameters but little info regarding performance can be derived from these parameters - a well-designed antenna will present minimal VSWR at its operating freq and will appear entirely resistive (no reactance)…but so will a dummy load.

It does look like a fun gadget to tinker with though.

John AE5X


#7

It won’t, but you could use any simulation software (4nec2 for example) to estimate gains and fine tune using the analyzer.

for those doing blind tests it’s a huge step forward

It will never replace an anechoic chamber with professional equipments.


#8

Speaking about the analyzer itself, lets discuss some of its readings?

For example, the S11 reading.

I’ve made tests with 3 cables (all of them tuned to 1090Mhz) with a 50 Ohm dummy load at the end.

  1. 50cm RG58 = -11dB
  2. 4M RG58 = -12dB
  3. 4M RG174 = -18dB

Is it correct to affirm the RG174 has a 3dB loss compared to a RG58 ((18-12)/2)?


#9

That would be a 6 dB loss - no need to divide by 2. Only 1 dB of loss going from 50cm to 4m of RG58 is questionable, assuming the freq used in both measurements is the same.


#10

How about these readings regarding open cable vs dummy load?


#11

I checked User Manual and found that “Cable length measurement” and “Transmission line characteristic impedance measurements” can be done only in Model N1201SAC.

I could not find N1201SAC on Banggood, but I found it on Aliexpress for US $249 (Click here)

On Aliexpress, I found another model N2201 for US $260, which is same as N1201SA, but can measure power also, and has two SMA ports “RF OUT” and “RF IN” (Click here)


#12

My fun didn’t last too much.

Left the analyzer ON while I was cutting the antenna and when I plugged it back there was no readings at all.

“R” remains “0.000”, SWR 99999, no matter open/load/short

Let’s how banggood’s customer support works


#13

@aldoir
First turn the device off, then on again.
If switching off-on does not solve the problem, try reset located at bottom of the device, where you plug in charging cable’s mini usb.


#14

Did it a couple of times. The reset button only power cycle it, didn’t find a way to hard reset it.

But I dont think it’s a software issue, looks like the signal generator section is dead.

Tried doing the callibration and now CAL1 always displays “R = 50Ohms” LOL


#15

So, measuring any DC shorted antenna such as a quad driven element would produce the same damaging effect?


#16

@aldoir: Did the failure occur after you tested a shorted antenna?

I did not try a shorted antenna, but specs say:
Measurement range - impedance 0.1Ω ~ 1000Ω (The absolute value of the impedance)

Please see the specifications in my post above.


#17

No, I was testing a sleeve dipole. To avoid any damage to the analyzer I disconnected it every time I need to cut/solder something but left it ON without any load. Did it a couple of times, then when I came back to plug the antenna to the analyzer realized it was reading R=0.0000


#18

Since the specs say that it can measure an impedance as low as 0.1 ohm, which is almost short circuit for all practical purposes, I dont feel testing short circuited antenna will damage it.


#19

Me too… dont think a testing device should/would burn by letting it on with open or short load


#20

Yes, you can short it without damage.

Having said that, mine went NUTS two days ago. Would go white-screen after only a couple minutes, claimed random charge% the entire time it was on, would shut off and then come back on, then refuse to shut off…

I had finally had enough and opened the case. When I removed the bottom plate, something fell out and bounced off my desk. I was never able to locate it but, looking at the board, I couldn’t see anything obviously wrong with it (was hoping for a cold solder joint, bad assembly, something. Nope. Everything looked peachy. I tightened the nuts that retain the RF connector and rotary switch and put it back together.

Hasn’t misbehaved since, though the battery meter still appears to be complete BS. From the sound of the thing that bounced off my desk, I think it was a piece of metal laying in there and occasionally making contact with stuff it shouldn’t, but I have no evidence of that. :neutral_face:

It’s still unreadably dim when not plugged into something, but since I can’t trust the battery meter, I’m using an external USB power pack (yes, another Tecknet product. 19200mAh pack p/n: BT1800. No, I don’t own stock in them. No, I’m not an affiliate. I genuinely like their power pack.) just to keep the backlight on and make it so I don’t have to guess whether the thing has discharged it’s battery again.

I’m going to have to buy another one eventually. Not looking forward to it, but I need it.