Re: Linear Amplifier Build
RF SSPA Builders - Facebook
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On Sun, 11 Apr 2021 at 18:25, Ashhar Farhan <farhanbox@...> wrote:
There is one on facebook. I am no longer on facebook so I can't retrieve the page's link.
- f
On Sun 11 Apr, 2021, 9:30 PM jerry@..., <jerry@...> wrote:
All,
I know this isn't the right forum for this - anybody know of
a forum for people building linear amps?
Last night, I had my first contact in some years. A pleasant
gentleman in Calgary. Unfortunately, he could not hear me as well as
I heard him, and we had to cut it short. So frustrating! I was
reminded of why we have linear amps. I was running barefoot, 100W.
So this morning, I hauled the 30L-1 out of the shed. Oh my aching
back! The 30L-1 is a 60's vintage Collins linear with 4 811-A tubes.
It's big. It's heavy. It does Not Belong in this bedroom.
I'm looking forward to building the LDMOS amp that I ordered on Ebay.
Also looking forward to the uBITX transceiver.
For me, ham radio is about two things - building equipment, and
chatting about building equipment :).
- Jerry KF6VB
On 2021-04-11 07:50, Evan Hand wrote:
Jerry,
I did do the testing of my modified v4 against my unmodified v5. I
have posted the power levels of the v4 on this thread. The IMD
measurements that I got are as follows:
Modified v4:
80meters: -21db
40meters: -19db
20meters: -20db
Unmodified v5:
80meters: -22db
40meters: -21db
20meters: -19db
As far as I can tell there is not really much difference in the SSB
performance with the change of C81 to 2670pF.
The only comment that I would make is that overall the IMD3
performance is not what I would like. Another 5 to 6 dB would have
been better.
Harmonics were down 51db for both rigs. I did not test for the spur
on the v4.
Harmonic tests were done with a TinySA connected through a homebrew
50db tap and a step attenuator.
IMD3 tests were done with an RSP1A and the RSP-Spectrum Analyzer
program using the same connections.
At this point, I do not plan to modify my v6 as CW is not a mode I
use. Also, I have other rigs that excel at QRP CW that I would use
instead. So my conclusion is to make the mod IF you want the CW
capability. It does not make sense if you are using SSB.
73
Evan
AC9TU
Links:
------
[1] /g/BITX20/message/87545
[2] /mt/81780486/243852
[3] /g/BITX20/post
[4] /g/BITX20/editsub/243852
[5] /g/BITX20/leave/10189903/243852/952924773/xyzzy
--
I'm here to add more value to the world than I'm using up.
|
Re: Linear Amplifier Build
Look at the schematics. Which CB amplifier is that? I would think to optimize the input and the output impedances of the amp (sorta of tuners), ferrites chokes at both the input and the output, effective lowpass filters and low input drive. Possibly add negative feedback at the finals of there aren't.
Hello everyone,
Having a linear amplifier for 15 to 10m, how should I proceed to make it work from 80 to 10m? Obviously adapting the LPF, anything else? 73's py2pvb "the neophyte".
Doesn't apply to amps you make for yourself that are not sold to others.? You still have to pass the third order harmonic reduction though. ? ? What about the FCC 15db gain max for the amps? Il lun 12 apr 2021 01:06 AM John Cunliffe W7ZQ < n2nep@...> ha scritto: They should be easy having a gain of 20db on HF I get that much on 2m from a pair of them.Careful though, with the gain they have you can easy get into feedback situations if you are not careful with the placement, relays, and shielding.
John
On Sun, Apr 11, 2021 at 06:03 PM, jerry@... wrote:
On 2021-04-11 12:41, Rafael Diniz wrote:
Hi Jerry,
Which transistors are in the finals of this kit you bought?
MRF300AN and MRF300BN. They are said to have an in-circuit gain of 20dB.
If that's true, then 6W in - gets you 600W out.
- Jerry KF6VB
--
¡_. _._
|
Re: Linear Amplifier Build
Hello everyone,
Having a linear amplifier for 15 to 10m, how should I proceed to make it work from 80 to 10m? Obviously adapting the LPF, anything else? 73's py2pvb "the neophyte".
Doesn't apply to amps you make for yourself that are not sold to others.? You still have to pass the third order harmonic reduction though. ? ? What about the FCC 15db gain max for the amps? Il lun 12 apr 2021 01:06 AM John Cunliffe W7ZQ < n2nep@...> ha scritto: They should be easy having a gain of 20db on HF I get that much on 2m from a pair of them.Careful though, with the gain they have you can easy get into feedback situations if you are not careful with the placement, relays, and shielding.
John
On Sun, Apr 11, 2021 at 06:03 PM, jerry@... wrote:
On 2021-04-11 12:41, Rafael Diniz wrote:
Hi Jerry,
Which transistors are in the finals of this kit you bought?
MRF300AN and MRF300BN. They are said to have an in-circuit gain of 20dB.
If that's true, then 6W in - gets you 600W out.
- Jerry KF6VB
--
¡_. _._
|
Re: Linear Amplifier Build
Doesn't apply to amps you make for yourself that are not sold to others. ?You still have to pass the third order harmonic reduction though. ?
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On Apr 14, 2021, at 11:58 PM, iz oos <and2oosiz2@...> wrote:
? What about the FCC 15db gain max for the amps? Il lun 12 apr 2021 01:06 AM John Cunliffe W7ZQ < n2nep@...> ha scritto: They should be easy having a gain of 20db on HF I get that much on 2m from a pair of them.Careful though, with the gain they have you can easy get into feedback situations if you are not careful with the placement, relays, and shielding.
John
On Sun, Apr 11, 2021 at 06:03 PM, jerry@... wrote:
On 2021-04-11 12:41, Rafael Diniz wrote:
Hi Jerry,
Which transistors are in the finals of this kit you bought?
MRF300AN and MRF300BN. They are said to have an in-circuit gain of 20dB.
If that's true, then 6W in - gets you 600W out.
- Jerry KF6VB
--
¡_. _._
|
Re: Linear Amplifier Build
There is a restriction in Part 97 section 97.317 that does place a limitation of 15db gain on an external RF amplifier to receive FCC certification. However certification is only needed for an external ham RF amplifier constructed by someone without a ham license. (97.315)
So yes, there is a 15db limit but it does not apply to an external RF amplifier used on the ham bands constructed by someone with an amateur radio license.
|
Please pardon my ignorance, but is certification required if you build your own amp for personal use?
Chris
At 15/04/2021, you wrote:
>On 2021-04-14 21:58, iz oos wrote:
>>What about the FCC 15db gain max for the amps?
>
>? ?I never heard of such a limit imposed by FCC.? They talk about maximum power output,
>frequency and signal purity.? I don't think they care how the gain is distributed in the stages.
>Could you give a reference for such a regulation?
>
>? ? ? ? ? ? ? ? - Jerry KF6VB
|
Re: Linear Amplifier Build
toggle quoted message
Show quoted text
At 15/04/2021, you wrote: On 2021-04-14 21:58, iz oos wrote:
What about the FCC 15db gain max for the amps? I never heard of such a limit imposed by FCC. They talk about maximum power output,
frequency and signal purity. I don't think they care how the gain is distributed in the stages.
Could you give a reference for such a regulation?
- Jerry KF6VB
|
Re: Linear Amplifier Build
On 2021-04-14 21:58, iz oos wrote: What about the FCC 15db gain max for the amps? I never heard of such a limit imposed by FCC. They talk about maximum power output, frequency and signal purity. I don't think they care how the gain is distributed in the stages. Could you give a reference for such a regulation? - Jerry KF6VB Il lun 12 apr 2021 01:06 AM John Cunliffe W7ZQ
<n2nep@...> ha scritto:
They should be easy having a gain of 20db on HF I get that much on
2m from a pair of them.Careful though, with the gain they have you
can easy get into feedback situations if you are not careful with
the placement, relays, and shielding.
John
On Sun, Apr 11, 2021 at 06:03 PM, jerry@... wrote:
On 2021-04-11 12:41, Rafael Diniz wrote:
Hi Jerry,
Which transistors are in the finals of this kit you bought? MRF300AN
and MRF300BN. They are said to have an in-circuit gain of 20dB.
If that's true, then 6W in - gets you 600W out.
- Jerry KF6VB Links:
------
[1] /g/BITX20/message/87645
[2] /mt/82016650/243852
[3] /g/BITX20/post
[4] /g/BITX20/editsub/243852
[5] /g/BITX20/leave/10189903/243852/952924773/xyzzy
|
Re: Linear Amplifier Build
What about the FCC 15db gain max for the amps?
Il lun 12 apr 2021 01:06 AM John Cunliffe W7ZQ < n2nep@...> ha scritto: They should be easy having a gain of 20db on HF I get that much on 2m from a pair of them.Careful though, with the gain they have you can easy get into feedback situations if you are not careful with the placement, relays, and shielding.
John
On Sun, Apr 11, 2021 at 06:03 PM, jerry@... wrote:
On 2021-04-11 12:41, Rafael Diniz wrote:
Hi Jerry,
Which transistors are in the finals of this kit you bought?
MRF300AN and MRF300BN. They are said to have an in-circuit gain of 20dB.
If that's true, then 6W in - gets you 600W out.
- Jerry KF6VB
|
Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
Those might be NOS parts that were made when IR was still an independent company. According to a document on IR date codes I found (), the code on that transistor would indicate a lead-free part that was made in week 40 of 2005 on line?D. But the markings aren't exactly like the examples in the document so that could also be a counterfeit part; the suspicious part is the single-part last line rather than two parts as shown in the document. Original IR parts should work in ham RF applications.
My earlier statement that Vishay bought International Rectifier was not entirely accurate. Vishay DID buy part of their business including the IRF power MOSFET line; they were included in a 2007 acquisition (). Vishay tried to buy the rest of IR in 2008 but their bid was rejected. After some other sales, what remained of IR was bought by Infineon in 2015.
On Wed, Apr 14, 2021 at 7:42 PM Bob Lunsford via <nocrud222= [email protected]> wrote: From the link, the image on the left is what I saw on the MPJA FETS;
I guess I have some LF power FETs, then.
Bob ¡ª KK5R
On Wednesday, April 14, 2021, 7:22:18 PM EDT, Jerry Gaffke via <jgaffke= [email protected]> wrote:
Bob, I have no idea if the MPJA FET's are legit. I do know that Mouser hasn't had anything but Vishay IRF510's?in the last 10 years. And that my Bitx40 and uBitx both have IRF510's with the Siliconix logo (Vishay owns Siliconix).
And that the bad clone here has an IR logo, the good part has a Siliconix logo: Not clear to me exactly who owns what bits of the old International Rectifier. It seems Vishay bought some of the product lines from IR back in 2007, and that Infineon later bought the rest of IR. The Infineon website has a datasheet for the IRF510, but it's dated 2003: ? ?? Does anybody know if? NFET's? are still being legitimately produced with the IR logo? Jerry, KE7ER On Wed, Apr 14, 2021 at 02:41 PM, Bob Lunsford wrote:
To help eliminate the guesswork and speculation, I opened up the two packages of URF520's I got from MPJA and found ALL of them were marked IR (International Rectifier) with date code 9-18 (Sept 2018)
?
That doesn't sound generic to me...
?
Bob ¡ª KK5R
?
Hide quoted text
?
On Wednesday, April 14, 2021, 3:35:14 PM EDT, Arv Evans <arvid.evans@...> wrote:
?
?
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.?
|
Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
I have no idea if you have bad URF520's.
What I know is that the only IRF510's that Mouser and Digikey
have carried over the last 10 years or so have been Vishay/Siliconix.
Jerry, KE7ER
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Show quoted text
On Wed, Apr 14, 2021 at 04:42 PM, Bob Lunsford wrote:
I guess I have some LF power FETs, then.
|
Re: Linear Amplifier Build
Look on youtube for LDMOS. Build up to 11K by adding pills. On Sun, Apr 11, 2021 at 5:04 PM jerry@... <jerry@...> wrote:
On 2021-04-11 12:41, Rafael Diniz wrote:
Hi Jerry,
Which transistors are in the finals of this kit you bought? MRF300AN and MRF300BN. They are said to have an in-circuit gain of
20dB.
If that's true, then 6W in - gets you 600W out.
- Jerry KF6VB
I'm using a BLF9120 based kit I bought on aliexpress, it works pretty
well, but up to 100W at most.
Rafael
PU2UIT
On 4/11/21 12:59 PM, jerry@... wrote:
All,
I know this isn't the right forum for this - anybody know of
a forum for people building linear amps?
Last night, I had my first contact in some years. A pleasant
gentleman in Calgary. Unfortunately, he could not hear me as well as
I heard him, and we had to cut it short. So frustrating! I was
reminded of why we have linear amps. I was running barefoot, 100W.
So this morning, I hauled the 30L-1 out of the shed. Oh my aching
back! The 30L-1 is a 60's vintage Collins linear with 4 811-A tubes.
It's big. It's heavy. It does Not Belong in this bedroom.
I'm looking forward to building the LDMOS amp that I ordered on
Ebay.
Also looking forward to the uBITX transceiver.
For me, ham radio is about two things - building equipment, and
chatting about building equipment :).
- Jerry KF6VB
On 2021-04-11 07:50, Evan Hand wrote:
Jerry,
I did do the testing of my modified v4 against my unmodified v5. I
have posted the power levels of the v4 on this thread. The IMD
measurements that I got are as follows:
Modified v4:
80meters: -21db
40meters: -19db
20meters: -20db
Unmodified v5:
80meters: -22db
40meters: -21db
20meters: -19db
As far as I can tell there is not really much difference in the SSB
performance with the change of C81 to 2670pF.
The only comment that I would make is that overall the IMD3
performance is not what I would like. Another 5 to 6 dB would have
been better.
Harmonics were down 51db for both rigs. I did not test for the spur
on the v4.
Harmonic tests were done with a TinySA connected through a homebrew
50db tap and a step attenuator.
IMD3 tests were done with an RSP1A and the RSP-Spectrum Analyzer
program using the same connections.
At this point, I do not plan to modify my v6 as CW is not a mode I
use. Also, I have other rigs that excel at QRP CW that I would use
instead. So my conclusion is to make the mod IF you want the CW
capability. It does not make sense if you are using SSB.
73
Evan
AC9TU
Links:
------
[1] /g/BITX20/message/87545
[2] /mt/81780486/243852
[3] /g/BITX20/post
[4] /g/BITX20/editsub/243852
[5] /g/BITX20/leave/10189903/243852/952924773/xyzzy
-- Allen/N1ATS/AAR4XG/ECCC
|
Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
From the link, the image on the left is what I saw on the MPJA FETS;
I guess I have some LF power FETs, then.
Bob ¡ª KK5R
On Wednesday, April 14, 2021, 7:22:18 PM EDT, Jerry Gaffke via groups.io <jgaffke@...> wrote:
Bob, I have no idea if the MPJA FET's are legit. I do know that Mouser hasn't had anything but Vishay IRF510's?in the last 10 years. And that my Bitx40 and uBitx both have IRF510's with the Siliconix logo (Vishay owns Siliconix).
And that the bad clone here has an IR logo, the good part has a Siliconix logo: Not clear to me exactly who owns what bits of the old International Rectifier. It seems Vishay bought some of the product lines from IR back in 2007, and that Infineon later bought the rest of IR. The Infineon website has a datasheet for the IRF510, but it's dated 2003: ? ?? Does anybody know if? NFET's? are still being legitimately produced with the IR logo? Jerry, KE7ER
On Wed, Apr 14, 2021 at 02:41 PM, Bob Lunsford wrote:
To help eliminate the guesswork and speculation, I opened up the two packages of URF520's I got from MPJA and found ALL of them were marked IR (International Rectifier) with date code 9-18 (Sept 2018)
?
That doesn't sound generic to me...
?
Bob ¡ª KK5R
?
Hide quoted text
?
On Wednesday, April 14, 2021, 3:35:14 PM EDT, Arv Evans <arvid.evans@...> wrote:
?
?
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.?
|
Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
Bob,
I have no idea if the MPJA FET's are legit.
I do know that Mouser hasn't had anything but Vishay IRF510's?in the last 10 years.
And that my Bitx40 and uBitx both have IRF510's with the Siliconix logo (Vishay owns Siliconix).
And that the bad clone here has an IR logo, the good part has a Siliconix logo:
Not clear to me exactly who owns what bits of the old International Rectifier.
It seems Vishay bought some of the product lines from IR back in 2007,
and that Infineon later bought the rest of IR.
The Infineon website has a datasheet for the IRF510, but it's dated 2003:
? ??
Does anybody know if? NFET's? are still being legitimately produced with the IR logo?
Jerry, KE7ER
toggle quoted message
Show quoted text
On Wed, Apr 14, 2021 at 02:41 PM, Bob Lunsford wrote:
To help eliminate the guesswork and speculation, I opened up the two packages of URF520's I got from MPJA and found ALL of them were marked IR (International Rectifier) with date code 9-18 (Sept 2018)
?
That doesn't sound generic to me...
?
Bob ¡ª KK5R
?
Hide quoted text
?
On Wednesday, April 14, 2021, 3:35:14 PM EDT, Arv Evans <arvid.evans@...> wrote:
?
?
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.?
|
Re: Latest from MPJA ,... including Pack of 10- IRF510 N Channel FET Transistor 100V output transistors
To help eliminate the guesswork and speculation, I opened up the two packages of URF520's I got from MPJA and found ALL of them were marked IR (International Rectifier) with date code 9-18 (Sept 2018)
That doesn't sound generic to me...
Bob ¡ª KK5R
On Wednesday, April 14, 2021, 3:35:14 PM EDT, Arv Evans <arvid.evans@...> wrote:
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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In junior high ( a few decades ago) we had to complete certain projects before we could work on what we wanted to. One was a simple metal chassis with three tube sockets mounted with various wires connecting pins (totally non-functional circuit) and all the wire nicely laced. This was to show we had the necessary skills to do things the right way. That was the one and ONLY time I ever laced wiring. I DON¡¯T feel cheated or anything like that. a few years later I was wiring up a microprocessor¡ no tube sockets in that one.
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On Apr 14, 2021, at 11:27 AM, Dennis Zabawa <kg4rul@...> wrote:
I still remember sore fingers from lacing cables with waxed linen cord.
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Totally agree!
Jack, W8TEE
On Wednesday, April 14, 2021, 3:49:17 PM EDT, Arv Evans <arvid.evans@...> wrote:
Jack
I have followed Dave's work for years, and have even built clones of some
of his projects.? Even with following his work precisely, my own results do
not come close to his precision and appearances.? My conclusion is that
it takes a specific type of artist vision to do that quality of work.? But that
does not mean that we cannot use his work for inspiration and as an
objective for our own builds.? I'm still trying to work up to his standards.
Arv _._
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 <jgaffke= [email protected]> 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
--
Jack, W8TEE
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Jack
I have followed Dave's work for years, and have even built clones of some
of his projects.? Even with following his work precisely, my own results do
not come close to his precision and appearances.? My conclusion is that
it takes a specific type of artist vision to do that quality of work.? But that
does not mean that we cannot use his work for inspiration and as an
objective for our own builds.? I'm still trying to work up to his standards.
Arv _._
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 <jgaffke= [email protected]> 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: 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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MadRadioModder
Raj vu2zap
Shirley Dulcey KE1L
Bob Lunsford