|
One more thingy.
I forgot to mention.? If you will note, the K7QO paper had one HC-49S (the short
crystal).? In a current shopping spree I find that the HC-49U has practically
disappeared from the face of the earth.
But that may be a good thing.? Note:? the HC-49S crystal in the paper had the
highest Q rating!!
Figure 1 in Chucks paper shows a HC-49U carefully taken apart. Try to find
a photograph of a HC-49S.? I dare you.? Some take one apart and do a high
resolution photo.? Please.
chuck
|
Hi Chuck, Yes, the HC-49S crystals can have excellent Q, but their Lm to Lc ratio is very high which makes them impractical for use in wider filters (SSB, etc). I have some measurements somewhere. If you'd like, I can dig them up and post them. 73 Mike M.? KU4QO
On Thu, Mar 13, 2025 at 11:44?AM chuck adams via <chuck.adams.phd= [email protected]> wrote: One more thingy.
I forgot to mention.? If you will note, the K7QO paper had one HC-49S
(the short
crystal).? In a current shopping spree I find that the HC-49U has
practically
disappeared from the face of the earth.
But that may be a good thing.? Note:? the HC-49S crystal in the paper
had the
highest Q rating!!
Figure 1 in Chucks paper shows a HC-49U carefully taken apart. Try to find
a photograph of a HC-49S.? I dare you.? Some take one apart and do a high
resolution photo.? Please.
chuck
|
What is SSB?? :-)
Yes, you're right.? Yes. Please post.? We need more data.
There are always tradeoffs between the two crystals.
One operates in the shear mode and the other in the
flex mode.? One of the reasons I want a internal photo.
Some machinist is going to have to do that as I no longer
have my mill and lathe.
I didn't think (do I ever?) to do a search of youtube and
now I find several videos on measuring different ways.
I did not compare with G3UUR fixture, but we can add that
to the list of 'to do' things or better known and 'bucket
list'.
chow,
chuck, look at the leader of 'send in the clowns'
toggle quoted message
Show quoted text
On 3/13/25 09:48, Michael Maiorana via groups.io wrote: Hi Chuck,
Yes, the HC-49S crystals can have excellent Q, but their Lm to Lc ratio is very high which makes them impractical for use in wider filters (SSB, etc).
I have some measurements somewhere. If you'd like, I can dig them up and post them.
73
Mike M.? KU4QO
On Thu, Mar 13, 2025 at 11:44?AM chuck adams via groups.io <> <chuck.adams.phd@...> wrote:
One more thingy.
I forgot to mention.? If you will note, the K7QO paper had one HC-49S
(the short
crystal).? In a current shopping spree I find that the HC-49U has
practically
disappeared from the face of the earth.
But that may be a good thing.? Note:? the HC-49S crystal in the paper
had the
highest Q rating!!
Figure 1 in Chucks paper shows a HC-49U carefully taken apart. Try
to find
a photograph of a HC-49S.? I dare you.? Some take one apart and do
a high
resolution photo.? Please.
chuck
|
Chuck, I'm still looking for the HC-49S data that I have, but I did find some data from a batch of 8MHz HC-49U crystals that I have. I used the method outlined in Jim?K8IQY's excellent paper on crystal characterization. I built the impedance-reducing circuit to measure, and used an HP8640B as the signal source, Philips PM6665 counter and an HP400EL RMS voltmeter for measurements. I created a spreadsheet to do the math that followed Jim's procedure. The first 4 columns are measured, with the following 4 calculated. Out of curiosity, I added an entry for the crystal's frequency in the G3UUR oscillator test fixture (labeled Fosc). The last column is the difference between the resonant?frequency measured with the signal generator and the G3UUR oscillator. I expected to see a fairly?consistent difference between the two methods, but I did not. You can see that in the last number in the?spreadsheet.
I think an advantage over the oscillator method is the crystal under test is only seeing very low power (-20dbm to -30dbm) which prevents heating. The crystal frequency in the G3UUR oscillator drifts quite a bit, although it does seem to stabilize over 5-10 minutes. I can't remember exactly, but I believe I waited the same amount of time with each crystal in that fixture before taking the reading. Maybe I have a problem with my G3UUR fixture?
Hopefully this is readable.
73 Mike M.? KU4QO
On Thu, Mar 13, 2025 at 1:03?PM chuck adams via <chuck.adams.phd= [email protected]> wrote: What is SSB?? :-)
Yes, you're right.? Yes. Please post.? We need more data.
There are always tradeoffs between the two crystals.
One operates in the shear mode and the other in the
flex mode.? One of the reasons I want a internal photo.
Some machinist is going to have to do that as I no longer
have my mill and lathe.
I didn't think (do I ever?) to do a search of youtube and
now I find several videos on measuring different ways.
I did not compare with G3UUR fixture, but we can add that
to the list of 'to do' things or better known and 'bucket
list'.
chow,
chuck, look at the leader of 'send in the clowns'
On 3/13/25 09:48, Michael Maiorana via wrote:
> Hi Chuck,
> Yes, the HC-49S crystals can have excellent Q, but their Lm to Lc
> ratio is very high which makes them impractical for use in wider
> filters (SSB, etc).
> I have some measurements somewhere. If you'd like, I can dig them up
> and post them.
> 73
> Mike M.? KU4QO
>
> On Thu, Mar 13, 2025 at 11:44?AM chuck adams via
> <> <chuck.adams.phd=[email protected]> wrote:
>
>? ? ?One more thingy.
>
>? ? ?I forgot to mention.? If you will note, the K7QO paper had one HC-49S
>? ? ?(the short
>? ? ?crystal).? In a current shopping spree I find that the HC-49U has
>? ? ?practically
>? ? ?disappeared from the face of the earth.
>
>? ? ?But that may be a good thing.? Note:? the HC-49S crystal in the paper
>? ? ?had the
>? ? ?highest Q rating!!
>
>? ? ?Figure 1 in Chucks paper shows a HC-49U carefully taken apart. Try
>? ? ?to find
>? ? ?a photograph of a HC-49S.? I dare you.? Some take one apart and do
>? ? ?a high
>? ? ?resolution photo.? Please.
>
>? ? ?chuck
>
>
>
>
>
>
|
Yes, it's very readable when I save the image and view it with gthumb in debian Linux.
Thanks a lot.
Question, if I may.? In the kitsandparts inventory, at one time, there were a large number
of crystal frequencies for the 1Ws and 5Ws.? Are there any left?
Again, thanks for the time and trouble to provide the data.? I'll put it with the values
that I create and what others have done.
BTW.? The delta-f I would attribute to heating.? I'll do the same experiment here with
a test setup that I'll build.? I think I'll come up with a PCB and put them on pcbway
and online in the files section.
Nice test equipment setup.
ciao dude,
chuck, aa7fo
toggle quoted message
Show quoted text
On 3/14/25 14:35, Michael Maiorana via groups.io wrote: Chuck,
I'm still looking for the HC-49S data that I have, but I did find some data from a batch of 8MHz HC-49U crystals that I have. I used the method outlined in Jim?K8IQY's excellent paper on crystal characterization. I built the impedance-reducing circuit to measure, and used an HP8640B as the signal source, Philips PM6665 counter and an HP400EL RMS voltmeter for measurements. I created a spreadsheet to do the math that followed Jim's procedure. The first 4 columns are measured, with the following 4 calculated. Out of curiosity, I added an entry for the crystal's frequency in the G3UUR oscillator test fixture (labeled Fosc). The last column is the difference between the resonant?frequency measured with the signal generator and the G3UUR oscillator. I expected to see a fairly?consistent difference between the two methods, but I did not. You can see that in the last number in the?spreadsheet.
I think an advantage over the oscillator method is the crystal under test is only seeing very low power (-20dbm to -30dbm) which prevents heating. The crystal frequency in the G3UUR oscillator drifts quite a bit, although it does seem to stabilize over 5-10 minutes. I can't remember exactly, but I believe I waited the same amount of time with each crystal in that fixture before taking the reading. Maybe I have a problem with my G3UUR fixture?
Hopefully this is readable.
image.png
73
Mike M.? KU4QO
On Thu, Mar 13, 2025 at 1:03?PM chuck adams via groups.io <> <chuck.adams.phd@...> wrote:
What is SSB?? :-)
Yes, you're right.? Yes. Please post.? We need more data.
There are always tradeoffs between the two crystals.
One operates in the shear mode and the other in the
flex mode.? One of the reasons I want a internal photo.
Some machinist is going to have to do that as I no longer
have my mill and lathe.
I didn't think (do I ever?) to do a search of youtube and
now I find several videos on measuring different ways.
I did not compare with G3UUR fixture, but we can add that
to the list of 'to do' things or better known and 'bucket
list'.
chow,
chuck, look at the leader of 'send in the clowns'
On 3/13/25 09:48, Michael Maiorana via groups.io
<> wrote:
> Hi Chuck,
> Yes, the HC-49S crystals can have excellent Q, but their Lm to Lc
> ratio is very high which makes them impractical for use in wider
> filters (SSB, etc).
> I have some measurements somewhere. If you'd like, I can dig
them up
> and post them.
> 73
> Mike M.? KU4QO
>
> On Thu, Mar 13, 2025 at 11:44?AM chuck adams via groups.io
<>
> <> <chuck.adams.phd@...> wrote:
>
>? ? ?One more thingy.
>
>? ? ?I forgot to mention.? If you will note, the K7QO paper had
one HC-49S
>? ? ?(the short
>? ? ?crystal).? In a current shopping spree I find that the
HC-49U has
>? ? ?practically
>? ? ?disappeared from the face of the earth.
>
>? ? ?But that may be a good thing.? Note:? the HC-49S crystal in
the paper
>? ? ?had the
>? ? ?highest Q rating!!
>
>? ? ?Figure 1 in Chucks paper shows a HC-49U carefully taken
apart. Try
>? ? ?to find
>? ? ?a photograph of a HC-49S.? I dare you.? Some take one apart
and do
>? ? ?a high
>? ? ?resolution photo.? Please.
>
>? ? ?chuck
>
>
>
>
>
>
|
Sorry, this was not intended for the group. I'll be more careful.
|
Hi Chuck, We have plenty of crystals, but they are all the frequencies for the different VXOs used in the 1W and 5W radio kits. The IF frequency crystals are all gone (apart from a handful?of each in my parts-bin).
I've always questioned the "match the frequency of oscillation as closely as possible" approach for picking crystals for IF filters. If you look at my data, the closest two crystals using the "passive" method that Jim describes are #7 and #8. They are within 2 Hz. But if you look at the results of those same two crystals using the oscillator method, they are 101 Hz apart. Which one is correct??
My anecdotal results are in using filters selected using Jim's method. They built excellent filters, confirmed by a SA with Tracking Generator plot. I haven't had the time, but would love to build one filter with the closest crystals and one with the widest spread and see how they differ in an actual filter. I'm sure someone must have already done this, but I wasn't able to find anything with some casual googling.
I think it is much more important to get rid of any crystals that have high Rs, and characterize the batch of crystals so that you can use the batch Lm and Cm values and model the best filters possible.?
Best regards and 73 Mike M.? KU4QO
On Fri, Mar 14, 2025 at 9:10?PM chuck adams via <chuck.adams.phd= [email protected]> wrote: Sorry, this was not intended for the group. I'll be more careful.
|
Mike,
With the ADC project, I plan to revive a research scenario that has been partially
done.? Use the K8IQY, G3UUR, K7QO and other matching techniques on a batch of
100 9.000MHz crystals.? Compare the techniques for comparisons.? I promise
to be unbiased.? Several people over the years have pointed out the heating
and drift issues associated with the G3UUR being in an active circuit and
having I^2*R_s power heating.
Let's say you have a Colpitts test oscillator for matching crystals.
Let the resonant frequency be f_0 = F(R_s,X_m,C_m,C_0).? Given
another identical crystal or one with close tolerances for all
parameters, will you get a small delta-f between the two.? I'd expect
it, but would not be surprised if I am wrong, again.? The math
says same parameters should give the same results.? Your results
are valid.? Jim's technique is correct.
Everyone is prone to using the same IF frequencies for each of the
bands.? Nowhere in the literature is that required.? You just
adjust your VFO range to match the range you need for each band.
As you pointed out, the R value should be as low as possible,
especially for IF filters.? In oscillators (and I am measuring
this) the R value effects the output magnitude.
I am willing to pay for and run tests on any batch of crystal
frequencies you do have in large quantity.? I'm sure I'm not
the only soul on the group that is looking for good deals on 100
crystals.? $0.25 or less each on ebay is OK, but we are always looking
for cheaper deals for being able to purchase a larger group
for matching.? Let me know offline, unless you also want to
help sell them off to the group at large.
And, yes, part of the research project is to test filters for
various parameter matches.? With the precise measurements,
we can see how SPICE modeling gives us filter curves that
match experimentation.? Are our ears still good enough to
distinguish between 300 and 400Hz bandwidth?
It's a lot of data, but that's what it's all about.? The lab
is open 24/7.
Thanks for the info and the group appreciates it also.? Again,
didn't mean to get the discussion going main stream, but it
is appreciated on my end.
ciao,
chuck, aa7fo
toggle quoted message
Show quoted text
On 3/15/25 11:05, Michael Maiorana via groups.io wrote: Hi Chuck,
We have plenty of crystals, but they are all the frequencies for the different VXOs used in the 1W and 5W radio kits. The IF frequency crystals are all gone (apart from a handful?of each in my parts-bin).
I've always questioned the "match the frequency of oscillation as closely as possible" approach for picking crystals for IF filters. If you look at my data, the closest two crystals using the "passive" method that Jim describes are #7 and #8. They are within 2 Hz. But if you look at the results of those same two crystals using the oscillator method, they are 101 Hz apart. Which one is correct?
My anecdotal results are in using filters selected using Jim's method. They built excellent filters, confirmed by a SA with Tracking Generator plot. I haven't had the time, but would love to build one filter with the closest crystals and one with the widest spread and see how they differ in an actual filter. I'm sure someone must have already done this, but I wasn't able to find anything with some casual googling.
I think it is much more important to get rid of any crystals that have high Rs, and characterize the batch of crystals so that you can use the batch Lm and Cm values and model the best filters possible.
Best regards and 73
Mike M.? KU4QO
On Fri, Mar 14, 2025 at 9:10?PM chuck adams via groups.io <> <chuck.adams.phd@...> wrote:
Sorry, this was not intended for the group. I'll be more careful.
|
G3URR crystal measurement method
Mike,
In one of his more recent postings to his website (~last two or three years), W7ZOI changed the oscillator's emitter resistor from 1K to 3k3 to reduce drive to the crystal under test and noted more stable readings when doing the measurements.
Regards, Walt ? K3ASW
On Thu, Mar 13, 2025 at 1:03?PM chuck adams via <chuck.adams.phd= [email protected]> wrote: What is SSB?? :-)
Yes, you're right.? Yes. Please post.? We need more data.
There are always tradeoffs between the two crystals.
One operates in the shear mode and the other in the
flex mode.? One of the reasons I want a internal photo.
Some machinist is going to have to do that as I no longer
have my mill and lathe.
I didn't think (do I ever?) to do a search of youtube and
now I find several videos on measuring different ways.
I did not compare with G3UUR fixture, but we can add that
to the list of 'to do' things or better known and 'bucket
list'.
chow,
chuck, look at the leader of 'send in the clowns'
On 3/13/25 09:48, Michael Maiorana via wrote:
> Hi Chuck,
> Yes, the HC-49S crystals can have excellent Q, but their Lm to Lc
> ratio is very high which makes them impractical for use in wider
> filters (SSB, etc).
> I have some measurements somewhere. If you'd like, I can dig them up
> and post them.
> 73
> Mike M.? KU4QO
>
> On Thu, Mar 13, 2025 at 11:44?AM chuck adams via
> <> <chuck.adams.phd=[email protected]> wrote:
>
>? ? ?One more thingy.
>
>? ? ?I forgot to mention.? If you will note, the K7QO paper had one HC-49S
>? ? ?(the short
>? ? ?crystal).? In a current shopping spree I find that the HC-49U has
>? ? ?practically
>? ? ?disappeared from the face of the earth.
>
>? ? ?But that may be a good thing.? Note:? the HC-49S crystal in the paper
>? ? ?had the
>? ? ?highest Q rating!!
>
>? ? ?Figure 1 in Chucks paper shows a HC-49U carefully taken apart. Try
>? ? ?to find
>? ? ?a photograph of a HC-49S.? I dare you.? Some take one apart and do
>? ? ?a high
>? ? ?resolution photo.? Please.
>
>? ? ?chuck
>
>
>
>
>
>
|
Thanks Walt. I'll give that a try and see what happens. I still have that small batch of crystals on my bench. 73 Mike M.? KU4QO
On Sun, Mar 16, 2025 at 2:05?AM Walter Thomas/K3ASW via <wt3i14297= [email protected]> wrote: G3URR crystal measurement method
Mike,
In one of his more recent postings to his website (~last two or three years), W7ZOI changed the oscillator's emitter resistor from 1K to 3k3 to reduce drive to the crystal under test and noted more stable readings when doing the measurements.
Regards, Walt ? K3ASW
On Thu, Mar 13, 2025 at 1:03?PM chuck adams via <chuck.adams.phd= [email protected]> wrote: What is SSB?? :-)
Yes, you're right.? Yes. Please post.? We need more data.
There are always tradeoffs between the two crystals.
One operates in the shear mode and the other in the
flex mode.? One of the reasons I want a internal photo.
Some machinist is going to have to do that as I no longer
have my mill and lathe.
I didn't think (do I ever?) to do a search of youtube and
now I find several videos on measuring different ways.
I did not compare with G3UUR fixture, but we can add that
to the list of 'to do' things or better known and 'bucket
list'.
chow,
chuck, look at the leader of 'send in the clowns'
On 3/13/25 09:48, Michael Maiorana via wrote:
> Hi Chuck,
> Yes, the HC-49S crystals can have excellent Q, but their Lm to Lc
> ratio is very high which makes them impractical for use in wider
> filters (SSB, etc).
> I have some measurements somewhere. If you'd like, I can dig them up
> and post them.
> 73
> Mike M.? KU4QO
>
> On Thu, Mar 13, 2025 at 11:44?AM chuck adams via
> <> <chuck.adams.phd=[email protected]> wrote:
>
>? ? ?One more thingy.
>
>? ? ?I forgot to mention.? If you will note, the K7QO paper had one HC-49S
>? ? ?(the short
>? ? ?crystal).? In a current shopping spree I find that the HC-49U has
>? ? ?practically
>? ? ?disappeared from the face of the earth.
>
>? ? ?But that may be a good thing.? Note:? the HC-49S crystal in the paper
>? ? ?had the
>? ? ?highest Q rating!!
>
>? ? ?Figure 1 in Chucks paper shows a HC-49U carefully taken apart. Try
>? ? ?to find
>? ? ?a photograph of a HC-49S.? I dare you.? Some take one apart and do
>? ? ?a high
>? ? ?resolution photo.? Please.
>
>? ? ?chuck
>
>
>
>
>
>
|
This is the W7ZOI article Walt mentioned showing the new emitter
resistor value. I too needed to change mine to the new 3.3 kohm
emitter resistor.
73,
Steve AA7U
On 3/16/2025 3:23 PM, Michael Maiorana
via groups.io wrote:
toggle quoted message
Show quoted text
Thanks Walt.
I'll give that a try and see what happens. I still have that
small batch of crystals on my bench.
73
Mike M.? KU4QO
On Sun, Mar 16, 2025 at
2:05?AM Walter Thomas/K3ASW via <wt3i14297= [email protected]>
wrote:
G3URR crystal measurement method
Mike,
In one of his more recent postings to his website
(~last two or three years), W7ZOI changed the oscillator's
emitter resistor from 1K to 3k3 to reduce drive to the
crystal under test and noted more stable readings when
doing the measurements.
Regards,
Walt ? K3ASW
On Thu, Mar 13, 2025 at
1:03?PM chuck adams via
<chuck.adams.phd= [email protected]>
wrote:
What
is SSB?? :-)
Yes, you're right.? Yes. Please post.? We need more data.
There are always tradeoffs between the two crystals.
One operates in the shear mode and the other in the
flex mode.? One of the reasons I want a internal photo.
Some machinist is going to have to do that as I no longer
have my mill and lathe.
I didn't think (do I ever?) to do a search of youtube and
now I find several videos on measuring different ways.
I did not compare with G3UUR fixture, but we can add that
to the list of 'to do' things or better known and 'bucket
list'.
chow,
chuck, look at the leader of 'send in the clowns'
On 3/13/25 09:48, Michael Maiorana via wrote:
> Hi Chuck,
> Yes, the HC-49S crystals can have excellent Q, but
their Lm to Lc
> ratio is very high which makes them impractical for
use in wider
> filters (SSB, etc).
> I have some measurements somewhere. If you'd like, I
can dig them up
> and post them.
> 73
> Mike M.? KU4QO
>
> On Thu, Mar 13, 2025 at 11:44?AM chuck adams via
> <>
<chuck.adams.phd=[email protected]>
wrote:
>
>? ? ?One more thingy.
>
>? ? ?I forgot to mention.? If you will note, the K7QO
paper had one HC-49S
>? ? ?(the short
>? ? ?crystal).? In a current shopping spree I find
that the HC-49U has
>? ? ?practically
>? ? ?disappeared from the face of the earth.
>
>? ? ?But that may be a good thing.? Note:? the HC-49S
crystal in the paper
>? ? ?had the
>? ? ?highest Q rating!!
>
>? ? ?Figure 1 in Chucks paper shows a HC-49U carefully
taken apart. Try
>? ? ?to find
>? ? ?a photograph of a HC-49S.? I dare you.? Some take
one apart and do
>? ? ?a high
>? ? ?resolution photo.? Please.
>
>? ? ?chuck
>
>
>
>
>
>
|
Thanks Steve.
I had another thought on this subject last night and I cobbled together a quick test. Stable frequency generators and high resolution counters might not be on everyone's bench. For fun, I wired up one of my Si5351 VFOs (a KitsAndParts Uni-VFO) and configured it to cover the range of frequencies of the 8MHz crystals I was testing. In "debug mode", the Uni-VFO outputs the relative frequency on a computer terminal. After the VFO, I put a resistive attenuator (simple 5k trim pot and 51 ohm resistor), then a simple low-pass filter at 10MHz. I turned it down to -20dbm output. I used that to feed Jim's (K8IQY) crystal test fixture that has two transformers to put the crystal in a lower impedance environment. The VFO has a 1Hz resolution, and is very stable after a few minutes of warm up.?
I measured a couple of the original test crystals again using this setup. The numbers were all within a few percent.?
So, it seems that you could use any of the many Si5351 VFOs out there, assuming they can be set for a 1Hz resolution, as a frequency source for this test fixture. It eliminates the need for an expensive RF generator and frequency counter. The only thing that is a little exotic in my setup is the RF voltmeter. I think you could easily put together a two-diode RF probe and just watch the DC voltage on a meter to find the peak and -3db points. Even better, wouldn't it be cool to automate the process?
73 Mike M.? KU4QO
|
Watching this conversation with interest. I am surprised nobody has mentioned using a nanoVNA to characterize crystals. I did this with a bag of 10MHz crystals, sorting to spreadsheet, and was able to build a dang good IF filter. I still have a bag of 12MHz crystals to go through. My nanoVNA has a ¡°crystal test¡° function, and spits out all the fun numbers like series resonant frequency, parallel resonant frequency, Rs, Cs, etc¡
I am no engineer, and am poorly educated compared to most on this list, so I assume there must be a compelling reason to use oscillators, frequency counters, and trigonometry etc., if only for the fun of it.
I personally doubt that the nanoVNA generates data that would even come close something provided by laboratory grade instrumentation, but it seems to be close enough for amateur work.
Apologies for any confusing typos, homonyms, rogue commas, that I may have missed¡ I dictated this email to my phone in a loud automotive shop environment during a break.
¡ªTim NC0Q
|
In this photo, I have not taken the time to calibrate/zero-out my test setup, so the displayed data is far from accurate. I¡¯m only trying to show how I test crystals. The other pic is my test jig. I use a normal 1/8W 50 ohm resistor for a calibration standard load, a jumper for the short, and room air for the open. Seems to work FB. I believe I paid around $75 dollars for my NanoVNA-H4.
¡ªTim NC0Q
|
Tim,
Do you have to install some firmware on your nanovna for it to work?? And that you have to make sure it is certain nanovna?? not all will work.?
?
Firmware is something called Dislord?
?
I have NanoVNA-H but not the H4.??? Will the NanoVNA-H work which has a 2.8" screen?
This is what it is.? Note, I got it much cheaper in the past - but inflation these days...
?
Probably best it have its own topic for using NanoVNA for matching crystals.
?
Anyways, I went searching, I found this link:
?
Look at the text:
Due to the discontinuation of NXP SA612A, we started to produce compatible chip ZeeTK NE602A, but due to the different chip manufacturing process, there is a slight difference between the two in the use of harmonics, new compatible ZeeTK NE602A NanoVNA-H rev3.7 and NanoVNA-H4 rev4.4 version hardware schematic.
?
Daniel KK4MRN
|
On Fri, Mar 21, 2025 at 08:18 PM, Daniel KK4MRN wrote:
Do you have to install some firmware on your nanovna for it to work?? And that you have to make sure it is certain nanovna?? not all will work.?
?
Firmware is something called Dislord?
?
I have NanoVNA-H but not the H4.??? Will the NanoVNA-H work which has a 2.8" screen?
This is what it is.? Note, I got it much cheaper in the past - but inflation these days...
?
Probably best it have its own topic for using NanoVNA for matching crystals.
?
Daniel,
?
A preamble: this group is loaded with wizards and these guys (and gals) know a lot about stuff. That I recommend other sources by no means discredits the folks here. It's just that it might be a little off topic. THIS IS NOT AN ADMONITION! Just pointing out other resources.?
?
(1) You do NOT have to install firmware on your NanoVNA to make it work. Depending on when you purchased yours, it will have firmware ("FW") it was initially "burned" with.
(2) The FW will be vary old and, while that is not at all bad, there are some new features that would make upgrading desirable.
(3) By the same token, you might want to upgrade your NanoVNA as well. The H with the smaller screen leaves a lot to be desired.
(4) Similarly, the later/latest FW upgrades will function on an H4 or other VNAs with a 4" screen.
(5) The H4 models' price have declined violently; they sell on Amazon for much less than when I purchased mine circa 2020.
(6) Then: over $100 Now: around $80 on Amazon. About $5-10 less on eBay if you want to wait a month for Chinese shipping.
(7) There are many YouTube videos with NanoVNA "intros". They are cursory and most don't handle the topic comprehensively.
(8) Recommend the following series as being more comprehensive. It starts with this one:
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(9) ..and includes with this one which is a comprehensive tour of the menu and, perforce, the machine:
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(10) Recommend viewing all at your leisure. These videos will fill a lot of the holes the other "intros" will leave you with.
(11) Similarly, there is a group -- nanovnausers -- that is loaded with folks and info on these little beasts.?
(12) Asking and searching threads reveal incredibly useful tidbits. Also cruise their "Messages" and their "Wiki sections as well.
(13) The Wiki contains overviews of models, FW, etc. Here is the H4 "Wiki"
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..note the directions on how to upgrade FW.
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I was pressed back into using (and therefore re-learning) how to use my H4 recently. Without the resources above, I never would have realized what a powerful little gadget these are.
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Good luck.
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--
William, k6whp
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"Cheer up, things could get worse. So I cheered up and things got worse."
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On Sun, Mar 16, 2025 at 02:05 AM, Walter Thomas/K3ASW wrote:
G3URR crystal measurement method
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Mike,
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In one of his more recent postings to his website (~last two or three years), W7ZOI changed the oscillator's emitter resistor from 1K to 3k3 to reduce drive to the crystal under test and noted more stable readings when doing the measurements.
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Regards,
Walt ? K3ASW
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When I added my message last night, I forgot to add that Wes adding Errata about that 3k3 resistor.? Not only the resistor changed but some of the formulas used in the Experimental Methods in RF Design book.
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Tim, Thanks for sharing that info. Personally, I didn't know that the NanoVNA was capable of making such measurements (at least not accurately). Maybe it's time for me to buy one of those clever little gadgets. Careful measurements with "oscillators, frequency counters" will give accurate results, but those methods are tedious. If the NanoVNA can provide accurate results easily, and is inexpensive, then it sounds like all the other methods have been made obsolete.?
Now I'm off to do some shopping :)? Thanks again. 73 Mike M.? KU4QO
On Fri, Mar 21, 2025 at 4:07?PM Tim Tyler II via <timtylerii= [email protected]> wrote: Watching this conversation with interest. I am surprised nobody has mentioned using a nanoVNA to characterize crystals. I did this with a bag of 10MHz crystals, sorting to spreadsheet, and was able to build a dang good IF filter. I still have a bag of 12MHz crystals to go through. My nanoVNA has a ¡°crystal test¡° function, and spits out all the fun numbers like series resonant frequency, parallel resonant frequency, Rs, Cs, etc¡
I am no engineer, and am poorly educated compared to most on this list, so I assume there must be a compelling reason to use oscillators, frequency counters, and trigonometry etc., if only for the fun of it.
?I personally doubt that the nanoVNA generates data that would even come close something provided by laboratory grade instrumentation, but it seems to be close enough for amateur work.
Apologies for any confusing typos, homonyms, rogue commas, that I may have missed¡ I dictated this email to my phone in a loud automotive shop environment during a break.
¡ªTim NC0Q
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?No problem, Michael,
Be sure to read K6WHP reply about two posts back in this thread; it is very comprehensive and will lead you to info that will help you decide which/where to buy yours. The nanovnausers IO group is indispensable.
I personally have a Nanovna-H4 and love it. Dislord firmware.
¡ªTim NC0Q
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I was pretty excited about crystal measurements and crystal filter construction a few (many?) years ago. I homebrewed Jim Kortge's?PVXO and initially used a diode detector with good results. Later I built W1FB's integration of several W7ZOI circuits into one crystal measurement instrument that had appeared in QST.
Over time, I started using an?AD8307 type detector for the measurements. I'd built another W7ZOI circuit for this.
While writing the C# software for the PHSNA system originated by W5JH and N5IB, I decided to attempt to automate crystal measurements. I wasn't at all sure it would work, but in fact it worked very well and I was pretty proud of it. I could characterize a crystal and report Cm, Lm and Rs in about ten seconds. The starting point was to provide the approximate resonant frequency and the attenuation of the fixture with a short in place of the crystal. The program would?start a few hundred Hz below the resonant frequency?and move upward until the exact resonant frequency was found, recording the frequency and attenuation found, then scan down for the -3 dB point and then up from resonance to get the other -3 dB point. This was enough information to allow calculation of the parameters.
I've done crystal measurements with the nanoVNA. It's a wonderful gizmo, but the tiny size and those SMA connectors put me off a little. Yes, I use nanoVNA-Saver.
73
Nick, WA5BDU
On Sun, Mar 23, 2025 at 9:21?AM Tim Tyler II via <timtylerii= [email protected]> wrote: No problem, Michael,
Be sure to read K6WHP reply about two posts back in this thread; it is very comprehensive and will lead you to info that will help you decide which/where to buy yours. The nanovnausers IO group is indispensable.
I personally have a Nanovna-H4 and love it. Dislord firmware.
¡ªTim NC0Q
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k6whp
Nick Kennedy