nanovna-users@groups.io

Re: NanoVNA and PC.

Having your device connect with DefuseDemo when it is in DFU mode is not the same as in normal running mode - there are 2 different drivers.
Before going any further - Verify when you connect your running device to the PC that it comes up as a comm port and connect to that comm port using the terminal program.

Show quoted text

On Thursday, December 2, 2021, 11:58:02 a.m. EST, A. via groups.io <ea7hj@...> wrote:  
 
 On Thu, Dec? 2, 2021 at 08:06 AM, DiSlord wrote:


When writing a bug report, it is good practice to provide as detailed a
description as possible.
Worked with everyone, which ones? What does it not work with? How does it
manifest? The device is not recognized in the system, or there is no
connection.
Thank you for answering DiSlord.
The programs that I try to use are Nanovna, Nanovna-APP, Nanovna-Saver and Nanovna-Sharp. All work with the original firmware v0.5.0 20200221 but the aforementioned programs are not connected with the last version DiSlord 20211121 that is the only one I have tried, at 101 points (either at 401 points). But Yes, it connects perfectly with the DfuSeDemo.
I do not report a problem, but a question in case someone knew the solution to my situation.
By the way, fantastic the latest firmware version. Thanks to Lot.
Regards

Re: NanoVNA and PC.

#25816

Where did you find this firmware? I can't seem to find that version
(20211121) anywhere.

73, Zack W9SZ

On Thu, Dec 2, 2021 at 9:51 AM A. via groups.io <ea7hj@...>
wrote:

I am a rookie in Nanovna but not in electronic and computer skills. I am
45 years old radioamateur.
My problem is that my NanoVNA-H4 with original firmware of 20200221 works
perfectly with all PC applications, but when I update it with the latest
Dislord Nanovna-H4_20211121 firmware, it stops working with PC programs.
I'm using W-10 64 Bits.
It is normal?. Any solution?. Up to what version can I go up without
losing that possibility?
Very grateful in advance.
Antonio - EA7HJ

Re: NanoVNA and PC.

#25815

On Thu, Dec  2, 2021 at 08:06 AM, DiSlord wrote:


When writing a bug report, it is good practice to provide as detailed a
description as possible.
Worked with everyone, which ones? What does it not work with? How does it
manifest? The device is not recognized in the system, or there is no
connection.
Thank you for answering DiSlord.
The programs that I try to use are Nanovna, Nanovna-APP, Nanovna-Saver and Nanovna-Sharp. All work with the original firmware v0.5.0 20200221 but the aforementioned programs are not connected with the last version DiSlord 20211121 that is the only one I have tried, at 101 points (either at 401 points). But Yes, it connects perfectly with the DfuSeDemo.
I do not report a problem, but a question in case someone knew the solution to my situation.
By the way, fantastic the latest firmware version. Thanks to Lot.
Regards

Re: NanoVNA and PC.

#25814

I check NanoVNA Sharp MOD v3
/g/nanovna-users/message/5406
This very old software, and can work if on device selected 101 points (STIMULUS->SWEEP POINTS->101)

This problem also related to NanoVNAPartner, need set 101 point (all old software hardware coded and use 101 points)

Re: NanoVNA and PC.

#25813

When writing a bug report, it is good practice to provide as detailed a description as possible.
Worked with everyone, which ones? What does it not work with? How does it manifest? The device is not recognized in the system, or there is no connection.

Re: NanoVNA and PC.

#25812

I have DiSlord's latest FW in my H and it is working fine with PC software.
Can you talk to your H4 console using a terminal program? I use TeraTerm for that.
If you can talk using a console application, you may have an issue elsewhere.

Show quoted text

On Thursday, December 2, 2021, 10:51:25 a.m. EST, A. via groups.io <ea7hj@...> wrote:  
 
 I am a rookie in Nanovna but not in electronic and computer skills. I am 45 years old radioamateur.
My problem is that my NanoVNA-H4 with original firmware of 20200221 works perfectly with all PC applications, but when I update it with the latest Dislord Nanovna-H4_20211121 firmware, it stops working with PC programs. I'm using W-10 64 Bits.
It is normal?. Any solution?. Up to what version can I go up without losing that possibility?
Very grateful in advance.
Antonio - EA7HJ

NanoVNA and PC.

#25811

I am a rookie in Nanovna but not in electronic and computer skills. I am 45 years old radioamateur.
My problem is that my NanoVNA-H4 with original firmware of 20200221 works perfectly with all PC applications, but when I update it with the latest Dislord Nanovna-H4_20211121 firmware, it stops working with PC programs. I'm using W-10 64 Bits.
It is normal?. Any solution?. Up to what version can I go up without losing that possibility?
Very grateful in advance.
Antonio - EA7HJ

Re: Precision Loads.

#25810

Joe,

Here is what the circuitry looks like at the SO239 connector on the MFJ 259B.  The diodes have a Peak Inverse Voltage of 15V so it does not take much of a mistake to destroy them. I

Roger

MFJ Front End.png

Re: Precision Loads.

#25809

On Wed, Dec  1, 2021 at 09:22 AM, Joe WB9SBD wrote:

My local club has a MFJ-259 analyzer. that we know is way out of wack. 
it needs re calibration.
 Joe,

I suspect you need more than re-calibration!  

The MFJ is not that accurate to begin with and only needs calibration if it was done poorly at the factory (this happens at MFJ) or you have replaced components.  

I own a MFJ-259-B and they are sensitive to having the front end diode detector bridge blown out from static or RF.  It happened to mine and I had to send it back for repair.

Here is what I suggest you do to see if you have a hardware failure.  Under 10 MHz. you should get good SWR and R/X readings even with a crummy load.  Just take some resistors from your bench poke one side down the SO239 and hold the other side to the threaded part with a clothespin,  See what you get for readings at from 2 to 10 MHz with 10, 25, 50, 75, 100 and 200 resistors..  You should be in the ballpark for SWR and R.  If you are not you are in for a repair job.  

Roger

Re: Precision Loads.

#25808

On 12/1/21 9:22 AM, Joe WB9SBD wrote:
Morning all!

I love my NanoVNA-H4. it JUST NOW probably has saved me from really screwing something up.

My local club has a MFJ-259 analyzer. that we know is way out of wack. it needs re calibration.

I found online a complex and very through calibration ummmm, how to do it.

it as a part needs some pure non-inductive restive loads.

12.5, 50, 75, 100, 200 ohms. and OPEN as well as SHORT.

I found online some nice amphanol pl-259's

and a set of precision resistors. It did not say if they were pure carbon or inductive.

Well I'm thinking they are inductive in some way.

I used a DVM,? actually 3 of them, to pick out perfect dead on resistive values for each load and soldered them into the P-259's

After soldering I again re measured with the DVM's the values and are dead on!

So went to do the calibration of the MFJ unit and when i attached each load. NONE were even close resistance wise in the display! I know this thing was out of alignment, but wow!

Then I got to think hmmmm whats the VNA say these loads are?

And WOW! It agrees with the MFJ.

the "50" ohm comes in like 80,,? the 200 is like 160,, etc. NONE are even close.

I did not make a note of the inductance if any, but suspect that is what is happening.

so anyone know of a place with resonable price loads in pl-259 format?

OR resistors that are for sure non inductive? so I can make my own again? 
For HF use and UHF connectors, I use Caddock non-inductive resistors in the TO-220 package. MP-820 series.? 20W (if heat sinked).? You can do better with SMTs, but "is it worth it?" for HF?? The nice thing is that if you accidentally transmit (at low power) into the load, it doesn't vanish in a puff of smoke.? They are a bit pricey ($9 these days)

Re: Precision Loads.

#25807

The MFJ, It's the local clubs that they loan out to people to use.

I know it's messd up so thought at least make it as accurate as it can be for them.

Joe WB9SBD

Show quoted text

On 12/1/2021 12:01 PM, Reinier Gerritsen wrote:
The only resistors that you should use are smd resistors. Use 0805 or 0603 sizes. For 50 Ohm, best results can be obtained with two 100 Ohm resistors in parallel. Short is a copper disk, open is a connector with the pin cut off. For the typical PL-259 use, the frequency is a few 100 MHz at the most, so a OPEN is almost identical to nothing connected at all.
Kurt Poulsen wrote an article on making a PL-259 calibration kit, see 
And when you have a NanoVNA, why bother with a shitty MFJ?

Op 1-12-2021 om 18:22 schreef Joe WB9SBD:
Morning all!

I love my NanoVNA-H4. it JUST NOW probably has saved me from really screwing something up.

My local club has a MFJ-259 analyzer. that we know is way out of wack. it needs re calibration.

I found online a complex and very through calibration ummmm, how to do it.

it as a part needs some pure non-inductive restive loads.

12.5, 50, 75, 100, 200 ohms. and OPEN as well as SHORT.

I found online some nice amphanol pl-259's

and a set of precision resistors. It did not say if they were pure carbon or inductive.

Well I'm thinking they are inductive in some way.

I used a DVM,? actually 3 of them, to pick out perfect dead on resistive values for each load and soldered them into the P-259's

After soldering I again re measured with the DVM's the values and are dead on!

So went to do the calibration of the MFJ unit and when i attached each load. NONE were even close resistance wise in the display! I know this thing was out of alignment, but wow!

Then I got to think hmmmm whats the VNA say these loads are?

And WOW! It agrees with the MFJ.

the "50" ohm comes in like 80,,? the 200 is like 160,, etc. NONE are even close.

I did not make a note of the inductance if any, but suspect that is what is happening.

so anyone know of a place with resonable price loads in pl-259 format?

OR resistors that are for sure non inductive? so I can make my own again?

Joe WB9SBD

Re: Precision Loads.

#25806

The only resistors that you should use are smd resistors. Use 0805 or 0603 sizes. For 50 Ohm, best results can be obtained with two 100 Ohm resistors in parallel. Short is a copper disk, open is a connector with the pin cut off. For the typical PL-259 use, the frequency is a few 100 MHz at the most, so a OPEN is almost identical to nothing connected at all.
Kurt Poulsen wrote an article on making a PL-259 calibration kit, see 
And when you have a NanoVNA, why bother with a shitty MFJ?

Op 1-12-2021 om 18:22 schreef Joe WB9SBD:

Show quoted text

Morning all!

I love my NanoVNA-H4. it JUST NOW probably has saved me from really screwing something up.

My local club has a MFJ-259 analyzer. that we know is way out of wack. it needs re calibration.

I found online a complex and very through calibration ummmm, how to do it.

it as a part needs some pure non-inductive restive loads.

12.5, 50, 75, 100, 200 ohms. and OPEN as well as SHORT.

I found online some nice amphanol pl-259's

and a set of precision resistors. It did not say if they were pure carbon or inductive.

Well I'm thinking they are inductive in some way.

I used a DVM,? actually 3 of them, to pick out perfect dead on resistive values for each load and soldered them into the P-259's

After soldering I again re measured with the DVM's the values and are dead on!

So went to do the calibration of the MFJ unit and when i attached each load. NONE were even close resistance wise in the display! I know this thing was out of alignment, but wow!

Then I got to think hmmmm whats the VNA say these loads are?

And WOW! It agrees with the MFJ.

the "50" ohm comes in like 80,,? the 200 is like 160,, etc. NONE are even close.

I did not make a note of the inductance if any, but suspect that is what is happening.

so anyone know of a place with resonable price loads in pl-259 format?

OR resistors that are for sure non inductive? so I can make my own again?

Joe WB9SBD

Precision Loads.

#25805

Morning all!

I love my NanoVNA-H4. it JUST NOW probably has saved me from really screwing something up.

My local club has a MFJ-259 analyzer. that we know is way out of wack. it needs re calibration.

I found online a complex and very through calibration ummmm, how to do it.

it as a part needs some pure non-inductive restive loads.

12.5, 50, 75, 100, 200 ohms. and OPEN as well as SHORT.

I found online some nice amphanol pl-259's

and a set of precision resistors. It did not say if they were pure carbon or inductive.

Well I'm thinking they are inductive in some way.

I used a DVM,? actually 3 of them, to pick out perfect dead on resistive values for each load and soldered them into the P-259's

After soldering I again re measured with the DVM's the values and are dead on!

So went to do the calibration of the MFJ unit and when i attached each load. NONE were even close resistance wise in the display! I know this thing was out of alignment, but wow!

Then I got to think hmmmm whats the VNA say these loads are?

And WOW! It agrees with the MFJ.

the "50" ohm comes in like 80,,? the 200 is like 160,, etc. NONE are even close.

I did not make a note of the inductance if any, but suspect that is what is happening.

so anyone know of a place with resonable price loads in pl-259 format?

OR resistors that are for sure non inductive? so I can make my own again?

Joe WB9SBD