Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
If building a test jig for evaluation of IRF510 devices, maybe we do not
have to test for actual performance of no-name or other-name devices. If the test jig were first used to evaluate a known good IRF510, then that
could become the standard to test against when evaluating other IRF510s.?
This decreases the need for expensive standards lab calibration of
test equipment and could speed up the process if many devices were to
be evaluated.
Arv _._
On Wed, Apr 14, 2021 at 4:11 AM Shirley Dulcey KE1L < mark@...> wrote: Vishay bought International Rectifier. The Vishay parts are the direct lineal descendents of the original IRF parts.
Technology has improved a lot since the introduction of IRF510 devices in the early 1980s.? Raw material grading, dhigh resolution handling and laser trimming has
become standard.? IRF has apparently licensed manufacturing of IRF devices to
Samsung and Vishay, and probably several others.? This would seem to indicate
that other manufacturer's clones of the original IRF device may be improved
models.? It would take some highly technical testing to determine if a particular
IRF510 device is as good as the original IRF device, or if it exceeds the quality
of its original design.
Large marketing organizations like Digikey or Mouser do not have testing facilities
for determining as-manufactured quality of one source over another.? We have
to trust that they have chosen the best quality and least-cost manufacturers.
Some on-line sales outlets are focused on buying and selling of end-of-run surplus components.? If these items are surplus for space industry or similar
high reliability projects they could be best-in-the-industry.? Or, if they are
surplus from the toy industry they could be worst-of-breed components.?
For the IRF510 devices it might be possible to build a decent test jig with
square-wave input, very high frequency scope monitoring, and calibration
to verify test results.? This is probably way beyond the capability of most
of us, and could be expensive to build.? Thoughts in this area are along the
line of using a calibrated and tuned detector at various harmonic frequency
points to see how much of the input harmonic energy is being output, and
at what level.? It gets complicated very quickly.
Arv _._
On Tue, Apr 13, 2021 at 10:49 AM Timothy Fidler < engstr@...> wrote: It is worth noting that Hans SUmmers of Qrp Labs will use the Vishay IRF510s and none other. He did a lot of tests before he came to that conclusion.
If you go to him for spare parts for a Qrp Labs kit - that is what he will sell you.? I don't believe he offers them as a? general on line sale part because of his restock costs.?
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Farhan, and others
Just finished reading over their group page.? At first glance it appears to
be the work of just two people who possibly work at Virginia Technical
College.? Might even be the basis of a specific class curriculum.? Several
images and documentation seems very close to what is available on
this forum (They do provide a link to this group down near the end of
their page).?
I see their page as valuable for its description of modulation and diode
ring modulators.? Should we reach out to them and offer support and
advice for their group?
Arv _._
On Tue, Apr 13, 2021 at 11:28 PM Ashhar Farhan < farhanbox@...> wrote: Interesting that they don't reach out to us here
An interesting link I discover today :?
73 - Pierre - FK8IH
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Re: QUESTION - is it possible to get a TX output of CW in A1A?
An answer for everyone!
Thank you all for the answers and for the small scheme that will allow me to add the CW transmission in A1A also in the EASY BITX that I am assembling, without resorting to strange solutions, but simply by moving the BFO in TX to beat 0 with the set frequency ... and at 700/800 Hz from beat 0 in reception!
Thanks again for the help and the confirmation of my expectations.
A cordial greeting to all, 73 de
IW4AJR Loris
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I still remember sore fingers from lacing cables with waxed linen cord.
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Re: The "COCORICO UBITX" The French Touch
Hello,
This aftermoon it's was the first "smoke test"... After checking the regulator voltage, I directly connected the arduino (already programmed from the old assembly) and connected the screen Nextion.This first power-up was like the arrival of "Perseverance" on Mars.?Everything is functional on the Nextion at the first attempt.?So I¡¯m pretty proud of my work in my home Nasa. LOLTomorrow, I have to test some quartz and? the different filters.
cdt
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Re: QUESTION - is it possible to get a TX output of CW in A1A?
Loris
A mixer inherently needs ac signals on 2 ports to produce an output.?
If we inject dc, it can bias the diodes, if enough turning them steadily on, so it can't mix anymore. Ubitx does this, eliminating the mixer function when transmitting cw.?
A small detail, if the stronger LO signal is present but not the weaker RF signal to be mixed, some of the LO signal will leak to the output, as it always does.
There are also simpler mixers using a single diode or transistor, that operate less ideal than the now much more common balanced mixer, that uses 2 or 4 devices.??
Curt
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Re: Talk: An Evening with Bob Heil K9EID Tuesday 13th April 8 pm BST (which is 1900 UTC)
A recording of the very interesting and indeed entertaining talk by Bob Heil is now available on YouTube:
73
Trystan G0KAY
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Re: QUESTION - is it possible to get a TX output of CW in A1A?
A keyed audio oscillator can work, but the oscillator and mike amp must feed a clean
sine wave at the correct level into the modulator to get a clean CW signal.
Far simpler to add a resistor from the keyer logic output into a mixer somewhere,
and the results are usually better.
Allard's Bitx40 mods unbalanced the modulator in the way that Loris was asking about.
As I recall, Allard started with a larger resistor on the CW-KEY line.
Some Bitx40 modulators had a weaker response, so he changed the resistor value to 4.7k,
Jerry, KE7ER
toggle quoted message
Show quoted text
On Wed, Apr 14, 2021 at 08:39 AM, Lawrence Galea wrote:
Why not use a keyed audio oscillator with suitable level adjustment at the mic input?
Hide quoted text
?
On Wed, Apr 14, 2021 at 12:14 PM Evan Hand < elhandjr@...> wrote: Loris,
I do not claim to be an expert on mixers.? I am only an amateur at understanding how they work.? Here is what I think would happen.
The DC voltage would be a 0Hz signal that is being added to the BFO frequency which would put the BFO signal on the input to the SSB filter.? So yes to your question.? Biasing the product detector would pass the BFO signal to the SSB filter.? In the ?BITX v6 That would send an 11.056Hz signal to a filter that is designed to pass signals from 11.057MHz to 11.059MHz so there would be a much-reduced signal being sent to the following stages for frequency mixing and amplification.? In a properly adjusted rig that could be as much as 30db to 40db down.
Note that the above BFO and Filter frequencies are approximate for description only.? They would vary depending on the specifics set for the rig under test and the actual SSB filter characteristics.
If the intent is to use it for CW like is done in the first mixer of the ?BITX, then as is done there you would need to adjust the BFO frequency on key down so that it will generate the correct signal to get through the SSB filter, then further adjust one of the later mixers to be on the correct frequency to transmit.
Again, these are my thoughts.? I am open to any comments or corrections.
73
Evan
AC9TU
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To each, his own.
I find Dave's work beautiful and would make everything I build look as nice if I could.
Jack, W8TEE
On Wednesday, April 14, 2021, 11:33:24 AM EDT, Jerry Gaffke via groups.io <jgaffke@...> wrote:
Squaring off all the wires like that was typical of radios built 100 years ago:
? ??
? ??
Ten years later stuff got boxed up in a metal chassis to where people never saw the wiring,
and so it didn't need to be quite so pretty.? I go for that more modern look.
Jerry, KE7ER
On Wed, Apr 14, 2021 at 08:13 AM, Jack, W8TEE wrote:
I know what you mean. Most of my kits look like controlled chaos even though you'd think a kit's PCB would make things look pretty good. Then there's the work by Dave Richards, AA7EE, where his Manhattan Style projects are works of art:
-- Jack, W8TEE
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Re: QUESTION - is it possible to get a TX output of CW in A1A?
Why not use a keyed audio oscillator with suitable level adjustment at the mic input?
On Wed, Apr 14, 2021 at 12:14 PM Evan Hand < elhandjr@...> wrote: Loris,
I do not claim to be an expert on mixers.? I am only an amateur at understanding how they work.? Here is what I think would happen.
The DC voltage would be a 0Hz signal that is being added to the BFO frequency which would put the BFO signal on the input to the SSB filter.? So yes to your question.? Biasing the product detector would pass the BFO signal to the SSB filter.? In the ?BITX v6 That would send an 11.056Hz signal to a filter that is designed to pass signals from 11.057MHz to 11.059MHz so there would be a much-reduced signal being sent to the following stages for frequency mixing and amplification.? In a properly adjusted rig that could be as much as 30db to 40db down.
Note that the above BFO and Filter frequencies are approximate for description only.? They would vary depending on the specifics set for the rig under test and the actual SSB filter characteristics.
If the intent is to use it for CW like is done in the first mixer of the ?BITX, then as is done there you would need to adjust the BFO frequency on key down so that it will generate the correct signal to get through the SSB filter, then further adjust one of the later mixers to be on the correct frequency to transmit.
Again, these are my thoughts.? I am open to any comments or corrections.
73
Evan
AC9TU
|
Squaring off all the wires like that was typical of radios built 100 years ago:
? ??
? ??
Ten years later stuff got boxed up in a metal chassis to where people never saw the wiring,
and so it didn't need to be quite so pretty.? I go for that more modern look.
Jerry, KE7ER
toggle quoted message
Show quoted text
On Wed, Apr 14, 2021 at 08:13 AM, Jack, W8TEE wrote:
I know what you mean. Most of my kits look like controlled chaos even though you'd think a kit's PCB would make things look pretty good. Then there's the work by Dave Richards, AA7EE, where his Manhattan Style projects are works of art:
|
Farhan:
I know what you mean. Most of my kits look like controlled chaos even though you'd think a kit's PCB would make things look pretty good. Then there's the work by Dave Richards, AA7EE, where his Manhattan Style projects are works of art:
Visit his web site and you'll find that all his stuff looks like this. Kinda makes me want to pack it all in and take up knitting.
Jack, W8TEE
On Wednesday, April 14, 2021, 10:59:02 AM EDT, Ashhar Farhan <farhanbox@...> wrote:
It is the economy of scale that kicks in with hf signals. It works out to be cheaper than the bill of materials! The way to keep the price under $100 is to build it the ugly way.? You can always scavenge from your junk. I can build an ugly radio in a day, in a pcb, it takes me a week! - f
On Wed 14 Apr, 2021, 4:56 PM Dennis Zabawa, < kg4rul@...> wrote: It seems their BOM totals $190USD.? You can buy a basic kit w/ acrylic front/rear panels and mike, shipped via DHL, for $160USD.? I guess there is a price for education!
--
Jack, W8TEE
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Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
Shirley is right, Vishay bought IR.
My story about the WA2EBY amp not working well at first with some non-IR IRF510 is vaguely mis-remembered.
toggle quoted message
Show quoted text
On Wed, Apr 14, 2021 at 03:10 AM, Shirley Dulcey KE1L wrote:
Vishay bought International Rectifier. The Vishay parts are the direct lineal descendents of the original IRF parts.
|
It is the economy of scale that kicks in with hf signals. It works out to be cheaper than the bill of materials! The way to keep the price under $100 is to build it the ugly way.? You can always scavenge from your junk. I can build an ugly radio in a day, in a pcb, it takes me a week! - f
On Wed 14 Apr, 2021, 4:56 PM Dennis Zabawa, < kg4rul@...> wrote: It seems their BOM totals $190USD.? You can buy a basic kit w/ acrylic front/rear panels and mike, shipped via DHL, for $160USD.? I guess there is a price for education!
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Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
JG I am well aware of all that in fact the Gate capacitance of the IRFz24 is about double that of the IRF 510 BUT? in general these will be going in a bolt on amp that has about 4-5 Wats pushed up the Wazoo. so you and afford a? bit of loss to gate capacitance at least up to and including 15 Mhz.??
In situations where you want real control over Cin and reproducible characteristics you go for the 6 dollar a piece Mitsubshi? RF qualified Mosfets . Basically on cost there are not many other options. At that price you get source = Ground tab and a device that runs much much cooler as a result .
Where the Z24 shines is? 1. It is not often counterfeited.? and 2. Thermally it is a lot better if you look at? the data sheets. So if you have a pair of each in the same amp both running 30W out with marginal heat sinking then the IRF510s will expire a lot earlier as? they might be running 25 C hotter than the IRFz24s for the same Po.
My tuppence worth.? TEF?
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It seems their BOM totals $190USD.? You can buy a basic kit w/ acrylic front/rear panels and mike, shipped via DHL, for $160USD.? I guess there is a price for education!
|
Re: QUESTION - is it possible to get a TX output of CW in A1A?
Loris,
I do not claim to be an expert on mixers.? I am only an amateur at understanding how they work.? Here is what I think would happen.
The DC voltage would be a 0Hz signal that is being added to the BFO frequency which would put the BFO signal on the input to the SSB filter.? So yes to your question.? Biasing the product detector would pass the BFO signal to the SSB filter.? In the ?BITX v6 That would send an 11.056Hz signal to a filter that is designed to pass signals from 11.057MHz to 11.059MHz so there would be a much-reduced signal being sent to the following stages for frequency mixing and amplification.? In a properly adjusted rig that could be as much as 30db to 40db down.
Note that the above BFO and Filter frequencies are approximate for description only.? They would vary depending on the specifics set for the rig under test and the actual SSB filter characteristics.
If the intent is to use it for CW like is done in the first mixer of the ?BITX, then as is done there you would need to adjust the BFO frequency on key down so that it will generate the correct signal to get through the SSB filter, then further adjust one of the later mixers to be on the correct frequency to transmit.
Again, these are my thoughts.? I am open to any comments or corrections.
73
Evan
AC9TU
|
Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
Vishay bought International Rectifier. The Vishay parts are the direct lineal descendents of the original IRF parts.
Technology has improved a lot since the introduction of IRF510 devices in the early 1980s.? Raw material grading, dhigh resolution handling and laser trimming has
become standard.? IRF has apparently licensed manufacturing of IRF devices to
Samsung and Vishay, and probably several others.? This would seem to indicate
that other manufacturer's clones of the original IRF device may be improved
models.? It would take some highly technical testing to determine if a particular
IRF510 device is as good as the original IRF device, or if it exceeds the quality
of its original design.
Large marketing organizations like Digikey or Mouser do not have testing facilities
for determining as-manufactured quality of one source over another.? We have
to trust that they have chosen the best quality and least-cost manufacturers.
Some on-line sales outlets are focused on buying and selling of end-of-run surplus components.? If these items are surplus for space industry or similar
high reliability projects they could be best-in-the-industry.? Or, if they are
surplus from the toy industry they could be worst-of-breed components.?
For the IRF510 devices it might be possible to build a decent test jig with
square-wave input, very high frequency scope monitoring, and calibration
to verify test results.? This is probably way beyond the capability of most
of us, and could be expensive to build.? Thoughts in this area are along the
line of using a calibrated and tuned detector at various harmonic frequency
points to see how much of the input harmonic energy is being output, and
at what level.? It gets complicated very quickly.
Arv _._
On Tue, Apr 13, 2021 at 10:49 AM Timothy Fidler < engstr@...> wrote: It is worth noting that Hans SUmmers of Qrp Labs will use the Vishay IRF510s and none other. He did a lot of tests before he came to that conclusion.
If you go to him for spare parts for a Qrp Labs kit - that is what he will sell you.? I don't believe he offers them as a? general on line sale part because of his restock costs.?
|
Jonathan Kayne, KM4CFT did post about the project here a couple of times - /g/BITX20/topic/only_noise_when_connected_to/71596559?p=,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,71596559
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QUESTION - is it possible to get a TX output of CW in A1A?
I ask to the most experienceds of me in the use of MIXERS:
if I inject a direct voltage (eg 1Vdc) to the BF input of the modulation mixer, is it possible that the BFO frequency comes out unmodulated?
What will be the attenuation of the output frequency?
Thanks for the replies.
73 de IW4AJR Loris
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Loris Bollina
Gerard
Trystan G0KAY
Shirley Dulcey KE1L