Ver. 1.42 and crystal measurement


Ted KX4OM
 

Welcome to the new moderators!

I've been measuring a lot of crystals the past week, about a hundred in all. About 50 in 8.192 HC49/U from a batch of 100 of which I had measured previously, and about 50 8.386 HC49/US that Harold Smith, KE6TI gave me a few years ago, about 100 in all. The latter have an average Q of around 200,000 while the 8.162 ones are about 100,000. The PHSNA makes it so easy, much moreso than my homebrew K8IQY PVXO and G3UUR rigs.

Here is my problem: A year ago, I upgraded to Rev 1.42 and used it to check my 40m dipole to set its length. That replaced my G5RV. Great, no problem. I had also used it to sweep some Heathkit SSB and CW crystal filters. That's all I used it for. I *think* I did the new crystal measurement frequency polynomial coefficients correctly when I installed 1.42; the ones in parameters.txt aren't Nick's from the 1.42 files. Last week when I started to measure the crystals, it would search for a long time and then would send an error message "Unable to find peak RF frequency" or something like that. I reinspected the parameters.txt file and everything looked okay. I ended up saving 1.42 to a bak directory and replaced it with 1.40, the last version I had used to do crystals back in 2018. What is odd is that I could do a response sweep in 1.42 on a crystal and get the peak frequency, but I couldn't sweep a jumpered holder in the standard PHSNA crystal test board (not using the amplifer, and always using an additional 4 dB attenuator from the SNA.

From reading the docs, I think I understand that I could put in some value for the five coefficients in 1.42 that aren't real, and that would allow the crystal measure to function as if it was a later version. Any ideas?

Ted, KX4OM


EB4APL
 

Hi Ted,

The parameters.txt file included with the distribution are an example
and must be replaced by one that is matched to your hardware. I believe
that there were not changes between versions 1.40 and 1.42 in the
crystal measurement code and I always use my parameters from the
previous version unless there is a change in the number of parameters.

Anyway to be sure do a full calibration and measure again.

You can also perform a sanity check, sweep the crystal on its fixture
using the normal sweep function and see what happens. Start with a
couple kHz low up to another couple high and when you see the peak
narrow the limits and use a 1 Hz resolution.

I'm not sure if I understand you correctly and it is what you did, but
maybe there is a problem with the test jig.

Please keep us informed about your findings.

73 de Ignacio, EB4APL


El 16/05/2020 a las 2:12, Ted KX4OM escribió:
Welcome to the new moderators!

I've been measuring a lot of crystals the past week, about a hundred in all. About 50 in 8.192 HC49/U from a batch of 100 of which I had measured previously, and about 50 8.386 HC49/US that Harold Smith, KE6TI gave me a few years ago, about 100 in all. The latter have an average Q of around 200,000 while the 8.162 ones are about 100,000. The PHSNA makes it so easy, much moreso than my homebrew K8IQY PVXO and G3UUR rigs.

Here is my problem: A year ago, I upgraded to Rev 1.42 and used it to check my 40m dipole to set its length. That replaced my G5RV. Great, no problem. I had also used it to sweep some Heathkit SSB and CW crystal filters. That's all I used it for. I *think* I did the new crystal measurement frequency polynomial coefficients correctly when I installed 1.42; the ones in parameters.txt aren't Nick's from the 1.42 files. Last week when I started to measure the crystals, it would search for a long time and then would send an error message "Unable to find peak RF frequency" or something like that. I reinspected the parameters.txt file and everything looked okay. I ended up saving 1.42 to a bak directory and replaced it with 1.40, the last version I had used to do crystals back in 2018. What is odd is that I could do a response sweep in 1.42 on a crystal and get the peak frequency, but I couldn't sweep a jumpered holder in the standard PHSNA crystal test board (not using the amplifer, and always using an additional 4 dB attenuator from the SNA.

From reading the docs, I think I understand that I could put in some value for the five coefficients in 1.42 that aren't real, and that would allow the crystal measure to function as if it was a later version. Any ideas?
Ted, KX4OM


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Nick Kennedy
 

Hi Ted,

It seems you're aware that Ignacio added another set of polynomial
constants to parameters.txt in revision 1.42, so I can't blame that. Yes,
you may have read in the User's Guide about "cheating" on the parameters
just to get the system working. I don't remember the step by step process,
but if you just read the dBm value somewhere in mid-range and "pretend"
that it's the same everywhere can calculate constants from that, you'll get
constants that "work" but don't properly compensate for changes in the
generator and crystal test fixture with frequency. I assume the higher
coefficients will come out zero, but don't remember for sure. Probably the
constant value C0 will equal the dBm value you measured at mid-band and all
other coefficients will be zero.

Anyway though ... you are getting the message that PHSNA can't find a peak.
In a case like that I'd do "normal" response sweep around the crystal
frequency and look at the plot to verify that there IS a peak. Maybe use 10
Hz steps, at least initially. If there's not one, maybe you have a hardware
issue. If there is one, make sure its frequency is consistent with the
scanning range you are telling PHSNA to use when you go into the crystal
test mode.

Good luck & keep us posted.

Nick, WA5BDU

On Fri, May 15, 2020 at 7:22 PM Ted KX4OM <wirehead73@gmail.com> wrote:

Welcome to the new moderators!

I've been measuring a lot of crystals the past week, about a hundred in
all. About 50 in 8.192 HC49/U from a batch of 100 of which I had measured
previously, and about 50 8.386 HC49/US that Harold Smith, KE6TI gave me a
few years ago, about 100 in all. The latter have an average Q of around
200,000 while the 8.162 ones are about 100,000. The PHSNA makes it so easy,
much moreso than my homebrew K8IQY PVXO and G3UUR rigs.

Here is my problem: A year ago, I upgraded to Rev 1.42 and used it to
check my 40m dipole to set its length. That replaced my G5RV. Great, no
problem. I had also used it to sweep some Heathkit SSB and CW crystal
filters. That's all I used it for. I *think* I did the new crystal
measurement frequency polynomial coefficients correctly when I installed
1.42; the ones in parameters.txt aren't Nick's from the 1.42 files. Last
week when I started to measure the crystals, it would search for a long
time and then would send an error message "Unable to find peak RF
frequency" or something like that. I reinspected the parameters.txt file
and everything looked okay. I ended up saving 1.42 to a bak directory and
replaced it with 1.40, the last version I had used to do crystals back in
2018. What is odd is that I could do a response sweep in 1.42 on a crystal
and get the peak frequency, but I couldn't sweep a jumpered holder in the
standard PHSNA crystal test board (not using the amplifer, and always using
an additional 4 dB attenuator from the SNA.

From reading the docs, I think I understand that I could put in some value
for the five coefficients in 1.42 that aren't real, and that would allow
the crystal measure to function as if it was a later version. Any ideas?

Ted, KX4OM




EB4APL
 

Hi,

Nick has a better memory that me and he is right, v 1.40 and v1.42 parameters.txt are not compatible because the later has a second set of polynomial coefficients, this one for the crystal measurement accessory compensation. You can follow the procedure for calibrating it in the Users Guide.Note that you can either edit the parameters.txt with the new values or you can edit it within the program in the calibration menu.

Best regards,

Ignacio EB4APL

El 16/05/2020 a las 14:05, Nick Kennedy escribió:
Hi Ted,

It seems you're aware that Ignacio added another set of polynomial
constants to parameters.txt in revision 1.42, so I can't blame that. Yes,
you may have read in the User's Guide about "cheating" on the parameters
just to get the system working. I don't remember the step by step process,
but if you just read the dBm value somewhere in mid-range and "pretend"
that it's the same everywhere can calculate constants from that, you'll get
constants that "work" but don't properly compensate for changes in the
generator and crystal test fixture with frequency. I assume the higher
coefficients will come out zero, but don't remember for sure. Probably the
constant value C0 will equal the dBm value you measured at mid-band and all
other coefficients will be zero.

Anyway though ... you are getting the message that PHSNA can't find a peak.
In a case like that I'd do "normal" response sweep around the crystal
frequency and look at the plot to verify that there IS a peak. Maybe use 10
Hz steps, at least initially. If there's not one, maybe you have a hardware
issue. If there is one, make sure its frequency is consistent with the
scanning range you are telling PHSNA to use when you go into the crystal
test mode.

Good luck & keep us posted.

Nick, WA5BDU


On Fri, May 15, 2020 at 7:22 PM Ted KX4OM <wirehead73@gmail.com> wrote:

Welcome to the new moderators!

I've been measuring a lot of crystals the past week, about a hundred in
all. About 50 in 8.192 HC49/U from a batch of 100 of which I had measured
previously, and about 50 8.386 HC49/US that Harold Smith, KE6TI gave me a
few years ago, about 100 in all. The latter have an average Q of around
200,000 while the 8.162 ones are about 100,000. The PHSNA makes it so easy,
much moreso than my homebrew K8IQY PVXO and G3UUR rigs.

Here is my problem: A year ago, I upgraded to Rev 1.42 and used it to
check my 40m dipole to set its length. That replaced my G5RV. Great, no
problem. I had also used it to sweep some Heathkit SSB and CW crystal
filters. That's all I used it for. I *think* I did the new crystal
measurement frequency polynomial coefficients correctly when I installed
1.42; the ones in parameters.txt aren't Nick's from the 1.42 files. Last
week when I started to measure the crystals, it would search for a long
time and then would send an error message "Unable to find peak RF
frequency" or something like that. I reinspected the parameters.txt file
and everything looked okay. I ended up saving 1.42 to a bak directory and
replaced it with 1.40, the last version I had used to do crystals back in
2018. What is odd is that I could do a response sweep in 1.42 on a crystal
and get the peak frequency, but I couldn't sweep a jumpered holder in the
standard PHSNA crystal test board (not using the amplifer, and always using
an additional 4 dB attenuator from the SNA.

From reading the docs, I think I understand that I could put in some value
for the five coefficients in 1.42 that aren't real, and that would allow
the crystal measure to function as if it was a later version. Any ideas?

Ted, KX4OM



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Ted KX4OM
 

Okay, guys thanks for the replies. I'll go down to the lab in the basement and replace the 1.40 files with the 1.42 files; I have them in separate directories to be able to rename their "backup" status folder to the PHSNA_VB folder to get them to work.

I'm sure it isn't hardware related because 1.40 works as the previous 1.3x versions did as well. I'm pretty sure that the crystal sweep coefficients1.42 parameters.txt are ones that I did when I first installed 1.42, but I'm not certain. Creeping old age, maybe :) All I know for sure is that they are not the example coefficients from the 1.42 release. The structure of the parameters.txt file checks out as to the fields required for the application to work. I will first run a "Response Sweep" on a crystal and confirm that it works as it did on the 1.42 a few days ago when I had problems wirh "crystal Meas". I'll try to measure a crystal, and then I'll do a full calibration from scratch as anticipate it won't find the peak, with the same error message.

I'll report back on the results. By the way, last night I created and uploaded a photo album, "KX4OM PHSNA photos" yesterday with photos of my equipment I built. The original log power meter is one I build about 15 years ago, and the new one is an upgraded unit with 6 AA cells and a completely copper shielded enclosure of the PC board and RG-316 including the analog A/D output. The meter is a surplus 50 uA Weston new old stock I've had for several years. The case is an unusual vertical form factor power supply case from an old Dell, as I recall. I use old PC supply cases for a lot of my projects. Both lpms read the the same. As a result of the PHSNA project, I upgraded the old lpm with an op-amp to calibrate the meter with a scale. I removed the old RadioShack meter and replaced it with another 1 mA one that I could remove the generic scale and glue a dB scale on. I have some more details on both of the lpms as well as the other PHSNA gear on my website at https://www.qsl.net/kx4om/

Ted, KX4OM


goldeaglemex strathman
 

Nick
Not sure of the date of your post but I am pleased to see that the PHSNA project has been saved. I came to the project late, missed the boards, etc but saved all the documentation and parts needed for the project. Assembled and tested several modules, located 3 HP435 power meters ($5.00 ea), very well designed enclosures.
Used 1 for the power meter and power supplies and another for the sweep generator and receiver. Got waylaid with chemo and radiation, got that behind me successfully and and now wish to complete the project . I intend to use the PHSNA to characterize the crystals for the receiver. So, looks like there will be enough of the community left to get me over the humps. Thanks for all the work you put into the PHSNA.

Ron, K6DNV. First licensed 1957 as KN6DNV now Extra.


Nick Kennedy
 

Ron,

Congratulations on getting those treatments behind you.

As for boards for the projects. I'm assuming Jim is not in the PHSNA board
business any longer. But there might be some on the list with extra boards
(myself included) that you or someone else coming late to the project could
use.

You might or not find the board configuration to match the hardware you've
been collecting, but possibly you could "beat to fit".

73-

Nick, WA5BDU

On Sat, May 16, 2020 at 7:57 PM goldeaglemex strathman <
goldeaglemex@gmail.com> wrote:

Nick
Not sure of the date of your post but I am pleased to see that the PHSNA
project has been saved. I came to the project late, missed the boards, etc
but saved all the documentation and parts needed for the project. Assembled
and tested several modules, located 3 HP435 power meters ($5.00 ea), very
well designed enclosures.
Used 1 for the power meter and power supplies and another for the sweep
generator and receiver. Got waylaid with chemo and radiation, got that
behind me successfully and and now wish to complete the project . I intend
to use the PHSNA to characterize the crystals for the receiver. So, looks
like there will be enough of the community left to get me over the humps.
Thanks for all the work you put into the PHSNA.

Ron, K6DNV. First licensed 1957 as KN6DNV now Extra.




goldeaglemex strathman
 

Nick
Thanks for the quick reply!

They (the VA) tell me that I'll probably croak from old age. I live in
Ensenada Mexico where screws let alone
toroids etc.don't exist so have been known to use the Beat Fit/Beat to Life
technic a few times.
When I get organized Ill do a post for boards. The nanoVNA learning curve
will have to wait!

Ron, K6DNV/XE


Nick
Not sure of the date of your post but I am pleased to see that the PHSNA
project has been saved. I came to the project late, missed the boards,
etc
but saved all the documentation and parts needed for the project.
Assembled
and tested several modules, located 3 HP435 power meters ($5.00 ea), very
well designed enclosures.
Used 1 for the power meter and power supplies and another for the sweep
generator and receiver. Got waylaid with chemo and radiation, got that
behind me successfully and and now wish to complete the project . I
intend
to use the PHSNA to characterize the crystals for the receiver. So, looks
like there will be enough of the community left to get me over the humps.
Thanks for all the work you put into the PHSNA.

Ron, K6DNV. First licensed 1957 as KN6DNV now Extra.






goldeaglemex strathman
 

Nick
Re: Board availability. I think I have the sweep generator and power meter covered. I could use the boards for the measurement Rx though. Noticed today that I had ordered a bag of 3.2768 crystals some time ago. Probably to avoid calculating filters and the diplexer. So, I can use those for the Rx board. Also will have to make sure I can mesh my hardware with the existing software. Great learning experience so far. How was the response to your offer to re-visit the PHSNA? With such easy access to nanoVNA's, etc. doubt that you are deluged with interest. Shame. Great learning experience all around.
73's
Ron K6DNV


Nick Kennedy
 

I don't know if interest in the measurement receiver ever "took off" so
there may not have been many boards. All the boards for the project were
produced by N5IB, except for cases where folks decided to "roll their own".

There has been renewed interest in the group as seen in more people joining
the list, as well as a few dropping out in response to the increased
traffic. ;^) However, I think most of them may just want to get access to
some of the files and info residing in the files section of the groups.io
site. Which is a good reason to sign up.

The nanoVNA is an amazing device for sure and I'm still learning mine. I do
find myself firing up the PHSNA occasionally, usually for crystal
measurements.

73

Nick, WA5BDU

On Tue, Jun 30, 2020 at 4:19 PM goldeaglemex strathman <
goldeaglemex@gmail.com> wrote:

Nick
Re: Board availability. I think I have the sweep generator and power meter
covered. I could use the boards for the measurement Rx though. Noticed
today that I had ordered a bag of 3.2768 crystals some time ago. Probably
to avoid calculating filters and the diplexer. So, I can use those for the
Rx board. Also will have to make sure I can mesh my hardware with the
existing software. Great learning experience so far. How was the response
to your offer to re-visit the PHSNA? With such easy access to nanoVNA's,
etc. doubt that you are deluged with interest. Shame. Great learning
experience all around.
73's
Ron K6DNV