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Antuino support group opened -- early antuino question

Don - KM4UDX
 

I have an early question (even before the support groups gets up and running...hahaha)

Is the Antuino able to be left in line with a tap & pad or something as a semi permanent basis to my uBITX? Right now I have an old MFJ power/SWR meter hooked up after the uBITX and before the antenna.  Is there a way to replace the swr/pwr meter with the  Antunio?

thanks!

Don
km4udx

Ashhar Farhan
 

Don,
The answer is yes, but ... the Antuino needs to be tuned within 10 khz of the ubitx to receive and display the modulation.
Being as sensitive as it is, you dont even need to connect it with the tap. A small piece of wire in the RF IN will pick up thr ubitx transmission.
- f

On Wed 14 Aug, 2019, 1:24 AM Don - KM4UDX, <dontAy155@...> wrote:
I have an early question (even before the support groups gets up and running...hahaha)

Is the Antuino able to be left in line with a tap & pad or something as a semi permanent basis to my uBITX? Right now I have an old MFJ power/SWR meter hooked up after the uBITX and before the antenna.  Is there a way to replace the swr/pwr meter with the  Antunio?

thanks!

Don
km4udx

Jerry Gaffke
 

The Antuino looks like a useful tool, well packaged.
I plan to get one.

But it won't be a replacement for your MFJ  power meter and SWR meter.

As Farhan pointed out, it would be very inconvenient to keep the Antuino tuned into
the frequency of the transmitter, the Antuino only sees one frequency at a time where
the MFJ is broadband.  And while the Antuino can measure the SWR of your antenna,
I don't think it can measure the SWR of an antenna while the transmitter is connected.

It could be used to measure the power coming out of a transmitter if you have
an appropriate resistive attenuator between the transmitter and the Antuino.
A small wire antenna on the Antuino might be used instead of the attenuator, but
the signal level seen by the Antuino will then vary with frequency and distance and
where your cat happens to be sitting.

Be very careful if using the Antuino around a transmitter, it would be easy
to feed it too much power and blow it out.

Jerry, KE7ER

 

On Tue, Aug 13, 2019 at 06:50 PM, Ashhar Farhan wrote:
Don,
The answer is yes, but ... the Antuino needs to be tuned within 10 khz of the ubitx to receive and display the modulation.
Being as sensitive as it is, you dont even need to connect it with the tap. A small piece of wire in the RF IN will pick up thr ubitx transmission.
- f
 
Hide quoted text

 

On Wed 14 Aug, 2019, 1:24 AM Don - KM4UDX, <dontAy155@...> wrote:
I have an early question (even before the support groups gets up and running...hahaha)

Is the Antuino able to be left in line with a tap & pad or something as a semi permanent basis to my uBITX? Right now I have an old MFJ power/SWR meter hooked up after the uBITX and before the antenna.  Is there a way to replace the swr/pwr meter with the  Antunio?

thanks!

Don
km4udx

Don - KM4UDX
 

Ashhar and Jerry -- thank you so much for the reply and info.  I better understand the general antuino application.  It is not a inline SWR/pwr meter, but it does a thousand other equally or more important jobs.  I'm always borrowing VNA from club members.  When I get a Antunio, I can stop being a pain in the neck to others. hahah.

P.S. I showed your email to my wife, and breathlessly exclaimed...look at this...Ashhar wrote to me!!!!  I did a little dance and told her I would never delete his email. [Obviously I need to get out more, but it is nice to have a few heroes out there, and you fit the bill. So a thousand thanks for all you've accomplished for all of us.  Okay, now I will stop sucking up. hahah.]

Don
km4udx

Evan Hand
 

I have ordered my Antunio, and am waiting for delivery, anxious to try it out .  The above comment from Don raises one question for me:  Is it a VNA or SNA.  As I understand the difference is that the VNA measures the phase angle as well as the magnitude of the impedance, an SNA just measures the magnitude of the impedance.  in reading the description on the HF Signals Web Page it states SNA capabilities.

As far as output, you can get a Smith Chart from a VNA, not from an SNA.

So the question is if the hardware would support a VNA application, and and if so does the software provided have both the real and imaginary values of the impedance?

73
Evan
AC9TU

Jerry Gaffke
 

Evan,

Looking at the Antuino schematic, it has an AD8307 at the output of the 25mhz filter
to tell the processor the magnitude of the received signal.
Nothing to tell the processor anything about phase.
So it's an SNA (Scaler Network Analyzer), not a VNA (Vector Network Analyzer)

You might think it needs both phase and magnitude to determine the SWR of an antenna.
But no, it uses a bridge circuit, and senses the difference between what the antenna does
to the signal and what a 50 ohm resistor does to the signal.  It assumes a 50 ohm environment.  
From post    https://groups.io/g/BITX20/message/63034
  I suppose R21,R29,R16, and an antenna on P3 would form a balanced
  bridge when the antenna is 50 ohms, CLK1 is driving the antenna and the top of the bridge.
  The ADE-1 RF port sees any imbalance across the bridge.
  CLK2 into the LO port is 25mhz above (or below) CLK1.

The cheapest VNA that I am aware of is the Vector Impedance Analyzer kit that Kees sells,
toward the bottom of this webpage:     http://www.qsl.net/k5bcq/Kits/Kits.html
Some other VNA's mentioned here:  https://groups.io/g/BITX20/message/56219
But I haven't looked over what's available out there for several years.

Jerry, KE7ER



On Wed, Aug 14, 2019 at 01:14 PM, Evan Hand wrote:
I have ordered my Antunio, and am waiting for delivery, anxious to try it out .  The above comment from Don raises one question for me:  Is it a VNA or SNA.  As I understand the difference is that the VNA measures the phase angle as well as the magnitude of the impedance, an SNA just measures the magnitude of the impedance.  in reading the description on the HF Signals Web Page it states SNA capabilities.

As far as output, you can get a Smith Chart from a VNA, not from an SNA.

So the question is if the hardware would support a VNA application, and and if so does the software provided have both the real and imaginary values of the impedance?

Evan Hand
 

Jerry,

Thank-you for the clarification. 

I was aware that you can measure SWR with just the scaler values, as I have built a resistor bridge based scanning SWR antenna analyzer, and purchased a cheap VNA with Smith chart capability.  I wanted to make sure that I had not missed something based on Don's mention of using the VNA capability of the Antuino  

73
Evan
AC9TU
AC9TU

Doug W
 

If you're looking for a cheap VNA this might be of interest.
https://groups.io/g/antennas/topic/nanovna_cheap_vna_on/31731387

I don't consider this to be competition at all for the Antuino.
--
www.bitxmap.com

kh6sky
 

I don't think anyone has mentioned the nanoVNA.  These go from 50 kHz up to 900 MHz, color touch screen, built with rechargable battery and PC sw.  They cost less than 70 USD.  Look at https://groups.io/g/nanovna-users/

It is strong competition I am afraid for the antuino,  Though I will probably still get an antuino because it will no doubt be the learning and experimentation platform that the BitX radios have become.

Gerry Kavanagh
 

Different use case, IMO. I have a NanoVNA, and it's great for measuring passive devices' S11 & S21 parameters, but for signal measurement (spectral purity, power level) it is useless. This is why I ordered the Antuino.
/ Gerry

Jerry Gaffke
 

I agree.
The nanoVNA cannot do all of the many things an Antuino can do,
and vice versa.  Nor does either one replace an inline SWR meter.

That said, the nanoVNA looks like a very nice addition to the toolbox.

Jerry


On Fri, Aug 16, 2019 at 02:07 AM, Gerry Kavanagh wrote:
Different use case, IMO. I have a NanoVNA, and it's great for measuring passive devices' S11 & S21 parameters, but for signal measurement (spectral purity, power level) it is useless. This is why I ordered the Antuino.