Re: FA-VA5 Available No Cost
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On Mon, Feb 10, 2025 at 12:22 PM, Tim Young via groups.io <tyoung@...> wrote: Thank you Wes, I have found a home for it.
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73
Tim
WB7UVH
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VY 73,
Wes WB7BR
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Re: FA-VA5 Available No Cost
Thank you Wes, I have found a home for it.
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73
Tim
WB7UVH
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Re: FA-VA5 Available No Cost
I can re-home it Tim. I mentor a large group of hams who are interested in antenna work. I am good in QRZ, and would be happy to reimburse you for whatever expenses you incur.
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VY 73,
Wes WB7BR
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I have an FA-VA5 that is not being utilized. I'd like to send it to someone who can use it. I'll pay postage as well.?
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Let me know if interested. This is not a scam! Check out my call, WB7UVH on QRZ.com
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Thanks,
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Tim
WB7UVH
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Re: Calibration after 1.09, what is the sign of the correction values ?
Thank you Michael.? I have the paper, and the numbers are negative.? The problem for me, is the statement "negative of the negative of the delays of the standard."? ?I watched a few videos, but when it got to inputting, they just blew past that, so there was no answer.? Thanks for your response, and I guess I will just input them exactly as stated, instead of trying to figure out the statement.?
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Re: Calibration after 1.09, what is the sign of the correction values ?
Thomas,
this is more a question to the designer of VNWA about his implementation (DG8SAQ). Please note that sdr-kits provides a download link (on the small paper of the kit) to a calibration value file for your specific BNC-Cal-Kit. If you load that fle in VNWA, the values will have the correct signs. The screenshot below shows the values for simple SOLT value from my own implementation. Negative numbers! This is also true for the arbritary model. Any reason not to use the arbritary model? This will give you more accurat results. Measuring a capacitor at 430 MHz, this will make a difference. Measuring SWR at 7 MHz, just go ahead with the ideal model.
Regards
Michael, DG5MK
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Calibration after 1.09, what is the sign of the correction values ?
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I've searched the messages, and could not find an answer to my question, so here goes:? In the VNWA program, under settings, Calibration Kit, the dialogue box for the Simple SOLT Model Settings, has this text in blue letters: "The delays above are correction values, i.e., the negative of the negative of the delays of the standard."? ? ?
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Does that mean that from the calibration data that came with my calibration kit, which has all negative numbers, I enter them into the dialogue box as positive numbers?? For example, the paper shows the male load delay as -246.74 ps.? Do I enter that into the software as +246.74?? Thanks in advance for any guidance.? Tom
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Re: Problem with FA-VA5 connecting with VNWA software
Thanks for the response Rick,
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Apparently that driver isn't compatible with Win 11 on my computer as it never showed a driver to download or install. I ended up deleting the CP210x Windows universal driver and went back to the silabs.com USB UART Bridge? Driver download page and downloaded another Windows version of the driver and it installed exactly as it was shown in the FA-VA5 manual so problem solved.?
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Now if I can only figure out how to use the VNWA software to view the s1p files!! It appears easier to do it using AntScope2.?
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Thanks again & 73,
Garry - K4OR
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Re: Problem with FA-VA5 connecting with VNWA software
You can go to properties on the "other device" and point it at the downloaded driver?
Also, Some drivers need to be installed?before plugging in a device.? (so that windows will properly recognise a device when it is connected)
On Thu, Oct 24, 2024 at 11:34?AM Garry - K4OR via <g.drummond= [email protected]> wrote: Greetings to All,
I am new to the group and to the FA-VA5. I am having a problem trying to get my FA-VA5 to work with the VNWA software. I have downloaded the software for the VNWA and it seems to work properly but it doesn't recognize or connect with the analyzer. I followed the instructions to download the driver and since I am running Windows 11 Home, I downloaded the CP210x Universal Windows driver. When installing, the steps didn't appear exactly as the instructions indicated. Under device manager, the driver doesn't show up under the COM & LPT ports. It shows up under "Other Devices" but only when the FA-VA5 is connected to my computer (picture attached) so I'm wondering if it is a driver problem or something else.?
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I've been a ham for over 50 years but trying to troubleshoot this is challenging for me in my senior years. Can anyone help me solve this problem? The USB cable should work as it transfers data from my digital camera to my computer and various card readers.
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Thanks & 73,
Garry - K4OR
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Problem with FA-VA5 connecting with VNWA software
Greetings to All,
I am new to the group and to the FA-VA5. I am having a problem trying to get my FA-VA5 to work with the VNWA software. I have downloaded the software for the VNWA and it seems to work properly but it doesn't recognize or connect with the analyzer. I followed the instructions to download the driver and since I am running Windows 11 Home, I downloaded the CP210x Universal Windows driver. When installing, the steps didn't appear exactly as the instructions indicated. Under device manager, the driver doesn't show up under the COM & LPT ports. It shows up under "Other Devices" but only when the FA-VA5 is connected to my computer (picture attached) so I'm wondering if it is a driver problem or something else.?
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I've been a ham for over 50 years but trying to troubleshoot this is challenging for me in my senior years. Can anyone help me solve this problem? The USB cable should work as it transfers data from my digital camera to my computer and various card readers.
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Thanks & 73,
Garry - K4OR
k4or@...
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Re: Can the Fa-Va5 be used like a signal generator ?
Frank,
yes, it is possible. At fr, the IF filter will change it's impedance significantly. However, most IF filters are designed for other system impedances than the 'normal' 50 Ohms, which makes SWR not the based method to test it. Just take a frequency sweep along the expected range (455 kHz, 9 MHz or whatever it is) and measure impedance |z| or retun loss s11 in dB at the input of the filter, while terminating the output of the filter with 100 Ohm or 200 Ohm. At fr, you should see a significant change. Sometimes these filters are so sharp that you will miss the change between samples. The same problems arrives with magnetic loops. The only solution is to narrow the frequency sweep, e.g. 400 kHz - 600 kHz for an expected 455 kHz IF filter, or take more samples. Using VNWA software you can extend the number of samples to 1000, 10000 or even more. Locally, the FA-VA 5 takes 100 samples.
Regards
Michael
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Re: Can the Fa-Va5 be used like a signal generator ?
Thank you so much Johan
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I apologize for being so late responding back to you. I never received a message from groups.io telling me that you responded back to my question.
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If you do not mind, I have another question.
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I know that the FA-VA5 can not do everything but I was wondering if it is capable of reading the fr (resonate frequency of a IF intermediate frequency of a IF filter ?
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Re: Notes on FA-VA 5 status
I knew when I made my suggestion regarding
changing to a UHF connector that I'd get push back from some
folks.? I also tried to qualify my use as being HF oriented as
well as a lot of use in the field.? I would dare say that if you
want to connect to the antennas/feedlines of today's amateurs,
>95% would be UHF connectors.? There's a place for other
connectors in other situations and geographical locations.? Even
that all purpose TNC (? ).
Recently there was an email on another reflector that showed prior
testing results for UHF connectors.? If you want to read the full
email, it was sent by Kimo Chun on the Tower Talk reflector on
6/17/2024 at 12:53 PM.? The original testing results were
published by K7FR in the 1996 time frame.? Some of the results
were:
f (MHz) Loss (W) dB
0.1 1 -0.00435
1 1.2 -0.00521
10 1.3 -0.00565
20 1.5 -0.00652
30 1.8 -0.00782
50 2.2 -0.00957
100 2.6 -0.01131
200 3.5 -0.01523
300 5 -0.02177
400 7 -0.03051
500 10 -0.04365
1000 15 -0.06564
1250 18 -0.07889
1500 28 -0.12334
1750 39 -0.17277**
2000 100 -0.45757**
** Connector failed before calorimeter stabilized.
When testing in the field, I can live with a UHF connector and that bump in impedance. Sure beats forgetting that all important adapter. In a somewhat static environment on the bench at home, almost any connector will suffice if it fits your test situation and environment.
If a new FA-6 came out with an N connector, I'd be looking to swap it out for a UHF connector. But again, that's me.
73 charlie, k1xx
On 6/30/2024 10:40 AM, Chuck WD4HXG via
groups.io wrote:
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HF focus
This is a very good point. There is an ongoing race for
higher frequencies. The more GHz the better. But covering
multiple GHz conflicts with low cost. The question
arrives, if this really should be the focus of such a
handheld device. I would agree that most users are
HF-users with some limited usage at 2 m and 70 cm. So the
main focus is HF. However, an UHF connector is simply too
bad. SMA is not robust enough for the field. Leaving BNC
or N-type. Let's see.
Either one has my vote provided the mass of the new variant
does not increase.?
I like the fact the connector is mechanically attached to
the enclosure and not
the pc board.
Batteries
The idea is going towards USB-C, using rechargeable
batteries. The European Union just made USB-C mandatory on
any mobile device. Therefore, also Apple needed to switch
to UCB-C. The USB-C standard defines power delivery on a
worldwide base. The voltages and currents are software
negotiated. Saying that, you should be able to use just
one fast charge USB-C adapter to charge any USB-C device.
Ok, I know that power outlets are different in USA and
Europe. So you need two.
This jostled the memory and reminded me I needed to check
the batteries. Any
device I own I now remove the
carbon-zinc or alkaline cells due to the risk of
leakage. Whatever choice you select, please pick one that
minimizes the risk of
damage that accompanies the generic AA and similarly
constructed cells.
Also, if some method can be implemented to limit lateral
forces applied to the
proposed USB-C connector, it would be greatly welcomed by
this old goat.
USB-C is ok on cell phones, but devices with more mass and
prone to being
dropped, I find the USB-C to be just as susceptible to
tearing from the PC board
with the abrupt lateral jerking that frequently occurs.?
Thank you for asking for end user input.
Regards
Chuck WD4HXG
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Re: Notes on FA-VA 5 status
HF focus
This is a very good point. There is an ongoing race for higher frequencies. The more GHz the better. But covering multiple GHz conflicts with low cost. The question arrives, if this really should be the focus of such a handheld device. I would agree that most users are HF-users with some limited usage at 2 m and 70 cm. So the main focus is HF. However, an UHF connector is simply too bad. SMA is not robust enough for the field. Leaving BNC or N-type. Let's see.
Either one has my vote provided the mass of the new variant does not increase.?
I like the fact the connector is mechanically attached to the enclosure and not
the pc board.
Batteries
The idea is going towards USB-C, using rechargeable batteries. The European Union just made USB-C mandatory on any mobile device. Therefore, also Apple needed to switch to UCB-C. The USB-C standard defines power delivery on a worldwide base. The voltages and currents are software negotiated. Saying that, you should be able to use just one fast charge USB-C adapter to charge any USB-C device. Ok, I know that power outlets are different in USA and Europe. So you need two.
This jostled the memory and reminded me I needed to check the batteries. Any
device I own I now remove the carbon-zinc or alkaline cells due to the risk of
leakage. Whatever choice you select, please pick one that minimizes the risk of
damage that accompanies the generic AA and similarly constructed cells.
Also, if some method can be implemented to limit lateral forces applied to the
proposed USB-C connector, it would be greatly welcomed by this old goat.
USB-C is ok on cell phones, but devices with more mass and prone to being
dropped, I find the USB-C to be just as susceptible to tearing from the PC board
with the abrupt lateral jerking that frequently occurs.?
Thank you for asking for end user input.
Regards
Chuck WD4HXG
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Re: Notes on FA-VA 5 status
One item of the VA5 that really needs improvement is the On/Off switch. The one in all the units I have bought for myself or for other people has proved to be 'touchy' at best, and intermittent as time goes by and wear increases.
BNC connectors are fine but if one wants a more secure connector how about the TNC?
Then we can all go and buy TNC-to-UHF, TNC-to-BNC, TNC-to-F, TNC-to-SMA, TNC-to-N, --- adaptors. Plus a new calibration kit.
A quicker scan rate could be useful, if this doesn't affect battery life too much.
And if operation with the DG?SAQ software, could that scan be faster as the VA5 is powered from the USB port now.
And standard, replaceable batteries in the VA5 are a real benefit. One doesn't need to worry about keeping the VA5 in carry-on baggage when travelling by aircraft. Or air-freighting the unit.
Peter LB0K.
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Re: Can the Fa-Va5 be used like a signal generator ?
Frank,
it is easy:
- Start FA-VA5
- Press and hold the left button (about 2 seconds) until the
main menu "Operating Mode" is shown
- Press middle button [Dwn] quickly three times to move down to
"Frequency Generator"
- Press left button [Sel] quickly to start the generator
- Press left button [D/S] quickly to cycle through the frequency
digits
- Press middle [-] or right [+] buttons quickly to step the
selected digit down or up
- Alternatively, press an hold middle [-] or right [+] buttons
for "autorepeat" on selected digit
- When finished, press and hold left button [D/S] to stop the
generator and return to the main menu
Please note that the output signal is a squarewave which contains
odd harmonics (i.e. 3f, 5f, 7f etc.)
73 Johan SM6LKM
Frank KF2YD wrote:
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Newbie just starting out -
I heard that the Fa-Va5 can be used like a signal generator ?
I looked at the operation manual and it looks like it has a very
steep learning curve.
Can anyone out there tell me how to just set up a single HF
frequency to be be generated ?
Appreciate any help
Frank
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Can the Fa-Va5 be used like a signal generator ?
Newbie just starting out -
I heard that the Fa-Va5 can be used like a signal generator ?
I looked at the operation manual and it looks like it has a very steep learning curve.
Can anyone out there tell me how to just set up a single HF frequency to be be generated ?
Appreciate any help
Frank
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Re: Successor to FA-VA5 (long!)
I guess it's time to wade in.? I've been making transmission line measurements since the days when I used a waveguide reflectometer and "calibrated" a scope screen with a grease pencil.
Thirty years later, when I retired, I (my company) had the pinnacle of performance an HP-8510C, a meter and a half rack cabinet costing 200K USD.? But suddenly I was back in the dark ages as far as precision measurements were concerned.
Then Paul, N2PK, came along with his VNA and I was in hobbyist heaven, after learning how to hand assemble parts that I couldn't see without a binocular microscope.? We are truly blessed to have the likes of? Paul, Tom, DG8SAQ, Michael, DG5MK and several others who have given us these wonderful devices.? I now own the original N2PK, a DG8SAQ VNWA, a FA-VA5, an AA55 Zoom and have tried and sold several others.? So to the point of this discussion:
I confess that I don't like the interface of the 'VA5 and wind up mostly using it as a test head run by VNWA software.? I'm sure this is my failing since I simply do not use it often enough to remember how to run it via the push buttons.? I've even stooped to dragging a laptop out side to do this at times.? Make no mistake, I think it's impressive to have this much control with a few buttons, it's just not my cup of tea.? BTW, I almost never use the AA55 for similar reasons (unfamiliarity) and the fact that I can't see the screen in the sunshine.
I'm also not thrilled with the case.? Perhaps it's just mine, with there is a little bit of warp so the unit never wants to sit flat on a table.? Assembling it and getting the push buttons through the holes is also an annoyance.
Otherwise:
I don't care what battery is used
The existing USB connector is fine with me, I don't like the USB-C trend, they look way to fragile to me. (I'm replacing an 80 USD laptop supply because the connector is bad.)
BNC is fine for the frequency range.
Don't care about bluetooth, signal generator, etc.
Bottom line, I feel fortunate to have a FA-VA5 but if a VA6 comes out, I'll buy one.
Wes? N7WS
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Re: Successor to FA-VA5 (long!)
Dear all,
thanks for your valuale input. Let me try to bring this together and evaluate what is doable and feasable.
Thanks again for taking the time. If there are more ideas or comments, don't hesitate to post them.
Regards
Michael, DG5MK
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Re: Notes on FA-VA 5 status
Hi Charlie,
thanks for your input. Some comments:
50 Ohm/ 75 Ohm
There is an option in the setup to change to 75 Ohm system impedance. Of course, this will not change the hardware of the bridge, but you should see correct values for 75 Ohm system impedance. F-connector is used here as well for 75 Ohm, but just for cable-TV.
HF focus
This is a very good point. There is an ongoing race for higher frequencies. The more GHz the better. But covering multiple GHz conflicts with low cost. The question arrives, if this really should be the focus of such a handheld device. I would agree that most users are HF-users with some limited usage at 2 m and 70 cm. So the main focus is HF. However, an UHF connector is simply too bad. SMA is not robust enough for the field. Leaving BNC or N-type. Let's see.
Batteries
The idea is going towards USB-C, using rechargeable batteries. The European Union just made USB-C mandatory on any mobile device. Therefore, also Apple needed to switch to UCB-C. The USB-C standard defines power delivery on a worldwide base. The voltages and currents are software negotiated. Saying that, you should be able to use just one fast charge USB-C adapter to charge any USB-C device. Ok, I know that power outlets are different in USA and Europe. So you need two.
TDR and transmission line loss without SOL-calibration
Accepted requests, more towards software and available processor power.
73, Michael DG5MK
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Wes WB7BR
Wes N7WS