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Re: IRF510 sale
I have some stock of darlingtons and wonder if there are any such transistors that can sub for the FETs because of the higher gain? Will the 3904s be able to drive a darlington with its much higher gain or would it require some kind of matching system? I believe using FETs eliminate much of the matching and drive attention but some here may know the answer to this better than I can guess. Bob ¡ª KK5R
On Friday, January 1, 2021, 12:58:37 PM EST, Jerry Gaffke via groups.io <jgaffke@...> wrote:
Here's an excellent post from Allison regarding the use of IRF510's vs the RD16HHF: ? ??/g/BITX20/message/53765 The IRF510's can work fine up through 30mhz. At 50mhz I'd go with something better, but Allison finds a way. Power from the 16db 2n3904 based driver stages falls off as the frequency goes up. That may well be more of a factor than the IRF510's in your "much less on the higher bands". Jerry, KE7ER On Fri, Jan 1, 2021 at 09:13 AM, Howard Fidel wrote: I have 19V and on 40 meters, about 20 watts. Much less on the higher bands. The IRF510 is a poor choice for higher power and higher frequencies, it is slew rate limited. |
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Re: Broke off screw mounts from screen
Sorry, I do not fully comprehend the nut "snapping off." I can see a screw snapping off but not the nut. Can you give more details? Bob ¡ª KK5R
On Friday, January 1, 2021, 3:53:18 PM EST, Gregg <greggahorton@...> wrote:
That's helpful for finding the right screw, but any idea how to fix the nuts that have snapped off? On Fri, Jan 1, 2021, 12:47 PM Bob Lunsford via <nocrud222=[email protected]> wrote:
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Re: Ideas for "bulletproofing" the uBitx
The V6 shines best on CW but I have been heard here in E Kentucky by others over the state and in Tennessee. Sure they have to crank up their RF gain to hear me but this is because too many hams use the RF gain as an HF equivalent to a 2M squelch control to limit static, etc. CW is famous for requiring a couple of watts where at least 20W would be needed with SSB. Remember the Heath HW-8 with only about 2-3W and still high on some people's want list... Bob ¡ª KK5R
On Friday, January 1, 2021, 3:32:25 PM EST, R. Tyson via groups.io <tysons2@...> wrote:
>The qrp-labs 10W PA blows away the many claims over the years in this forum >that the IRF510's are not suitable as RF transistors.? >It simply works, flat and clean, from 3.5 to 30mhz. I can also vouch for the QRP-Labs 50 watt amp. Using a pair of IRF510's in push pull and a good heat sink it just......???? works. Using CW it barely gets warm even after a lengthy over on my part.? Give the IRF510's a decent heat sink, don't require them to try and do the impossible and they are very good. They are also very cheap but if you need replacements make sure they are genuine products. Why oh why do people buy radio kit and then try to screw the ultimate, or even a bit more, out of it ? For those who don't know, or realise, if you are running 5 watts and receiving an S5 report then you would have to increase the power fourfold to gain another S point on your report. After raising it fourfold again you would gain another S point. You have to throw increasing amounts of power into gaining just one S point on your signal report.. it is more effective to improve the antenna system. e.g. 5 watts = S5 20 watts = S6 80 watts = S7 160 watts = S8 640 watts S9 Reg??????????????????????? G4NFR |
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Re: Broke off screw mounts from screen
Ian, you said it best... Thanks. Bob ¡ª KK5R
On Friday, January 1, 2021, 3:29:28 PM EST, Ian Reeve <ian.radioworkshop@...> wrote:
The World is a mix of new and earlier standards. As a resident of the UK we now use metric although a fair few folk who work on older equipment still need to use Imperial measurements as well as knowledge of other engineering standards. Of course we use Litres for liquids but the containers still mostly have the equivalent in Pints. Our American friends use Miles,Feet and Inches. ¡°The U.S. is one of the few countries globally which still uses the Imperial system of measurement, where things are measured in feet, inches, pounds, ounces, etc.¡± Its an eclectic mix! ? 73 de M0IDR Sent from for Windows 10 ? From: Loris IW4AJR via groups.io
Sent: 01 January 2021 19:46 To: [email protected] Subject: Re: [BITX20] Broke off screw mounts from screen ? Hy Bob The fact remains that in the world 6/7 billion people use the Decimal Metric System, that the ISO itself has established systems of multiples and submultiples related to the Decimal system ... I don't think that 400 or 500 million people, equal to only the 7% of the world population can continue to burden EXTRA COST over all the equipment, machinery and mechanics they import from the rest of the world with absurd costs for doubler the ingeniering for the rest of the world and maintain a measurement system that has been abandoned even by their own scientists ... I know the inch metric comparison rules, but now, in the third millennium they are absurd and anachronistic !?it is time for the legacies of the past to be left in the past ... the future awaits us ! and the future does not belong exclusively
to the USA, however big and important they may be, but to the whole world, from Europe to Asia and Africa and, not to forget, South America! ------- ? |
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Re: Broke off screw mounts from screen
Loris, I can bend both ways. To people as here, that are taught the English system, it is easier and simpler for them to stay mainly with the English system because of tradition and seeing no need to learn a second system, even though it is based on the decimal system, easier to manipulate mathematically, etc., etc. You cannot convince me the metric system is more logical and common sense because I already know this. This cannot as easily be taught or accepted by those who are entrenched in a system that they have been taught since a child but with use, they can learn. I like futbol and do not necessarily like American Football but here in America, this causes some of my friends to wonder about me. Watching the way Europeans and many other countries play futbol is a pleasure to me, although some women's teams do not cause this excitement nearly as much... Bottom line, you don't have to convince me that the metric system is best on many fronts. Most in science and technology agree on this. However: "Everyone's taste is in his own mouth." {;-> Bob ¡ª KK5R
On Friday, January 1, 2021, 2:47:02 PM EST, Loris IW4AJR via groups.io <lorisbollina@...> wrote:
Hy Bob The fact remains that in the world 6/7 billion people use the Decimal Metric System, that the ISO itself has established systems of multiples and submultiples related to the Decimal system ... I don't think that 400 or 500 million people, equal to only the 7% of the world population can continue to burden EXTRA COST over all the equipment, machinery and mechanics they import from the rest of the world with absurd costs for doubler the ingeniering for the rest of the world and maintain a measurement system that has been abandoned even by their own scientists ...
I know the inch metric comparison rules, but now, in the third millennium they are absurd and anachronistic !?it is time for the legacies of the past to be left in the past ... the future awaits us ! and the future does not belong exclusively to the USA, however big and important they may be, but to the whole world, from Europe to Asia and Africa and, not to forget, South America!
-------73 de IW4AJR Loris |
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Re: Broke off screw mounts from screen
Remember that the measurement is from the max mating surface (tip) to contact surface or the overall length. Therefore, with flathead screws, it is not the length of thread, it is from the end of the screw to the flat/surface (top) of the screw. This is obvious by process of elimination. Bob ¡ª KK5R
On Friday, January 1, 2021, 12:28:01 PM EST, Gregg <greggahorton@...> wrote:
That makes sense, I should have gotten out my calipers On Fri, Jan 1, 2021, 4:37 AM Bob Lunsford via <nocrud222=[email protected]> wrote:
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Re: Broke off screw mounts from screen
Hello,?
Remember! Lol When our fabulous Concorde was made parts of airplanes were made in Great Britain. They assembled perfectly in the hundredth of minutes with the pieces made in France despite the fact that their scale was in inch. No computer, everything was done with a drawing board. Too bad it made a little noise..... for our American friends (LOL) |
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Re: Broke off screw mounts from screen
Ian Reeve
¿ªÔÆÌåÓýThe World is a mix of new and earlier standards. As a resident of the UK we now use metric although a fair few folk who work on older equipment still need to use Imperial measurements as well as knowledge of other engineering standards. Of course we use Litres for liquids but the containers still mostly have the equivalent in Pints. Our American friends use Miles,Feet and Inches. ¡°The U.S. is one of the few countries globally which still uses the Imperial system of measurement, where things are measured in feet, inches, pounds, ounces, etc.¡± Its an eclectic mix! ? 73 de M0IDR Sent from for Windows 10 ? From: Loris IW4AJR via groups.io
Sent: 01 January 2021 19:46 To: [email protected] Subject: Re: [BITX20] Broke off screw mounts from screen ? Hy Bob The fact remains that in the world 6/7 billion people use the Decimal Metric System, that the ISO itself has established systems of multiples and submultiples related to the Decimal system ... I don't think that 400 or 500 million people, equal to only the 7% of the world population can continue to burden EXTRA COST over all the equipment, machinery and mechanics they import from the rest of the world with absurd costs for doubler the ingeniering for the rest of the world and maintain a measurement system that has been abandoned even by their own scientists ... I know the inch metric comparison rules, but now, in the third millennium they are absurd and anachronistic !?it is time for the legacies of the past to be left in the past ... the future awaits us ! and the future does not belong exclusively
to the USA, however big and important they may be, but to the whole world, from Europe to Asia and Africa and, not to forget, South America! ------- ? |
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Re: Broke off screw mounts from screen
Hy Bob
The fact remains that in the world 6/7 billion people use the Decimal Metric System, that the ISO itself has established systems of multiples and submultiples related to the Decimal system ... I don't think that 400 or 500 million people, equal to only the 7% of the world population can continue to burden EXTRA COST over all the equipment, machinery and mechanics they import from the rest of the world with absurd costs for doubler the ingeniering for the rest of the world and maintain a measurement system that has been abandoned even by their own scientists ...
I know the inch metric comparison rules, but now, in the third millennium they are absurd and anachronistic !?it is time for the legacies of the past to be left in the past ... the future awaits us ! and the future does not belong exclusively to the USA, however big and important they may be, but to the whole world, from Europe to Asia and Africa and, not to forget, South America!
-------73 de IW4AJR Loris |
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Re: Ideas for "bulletproofing" the uBitx
I called the MPJA 800-number 800-652-6733 and did it over the phone for two packages of ten plus an impedance/capacitance meter (for $22.95) and had it all shipped for $6.95 and it took me only about five minutes. The link for the transistors? now shows an offer for resistors. The call attendant said she'd look to see if they had any left. She said they'd send them but I suspect they are sold out by now because the transistor link now shows resistors. You can call to see if any left. It's such a common transistor that it's not hard to find them. Jameco has them for 99-cents each (10+ for 85-cents):
On Friday, January 1, 2021, 12:06:21 PM EST, Mike Morneau <ve3mic@...> wrote:
Not to mention RF parts availability.? IRF510s can be found almost anywhere.? Anyone that has tried to source RF transistors I'm sure can appreciate this -especially those living in remote areas. 73 de Mike |
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Re: IRF510 sale
"Power from the 16db 2n3904 based driver stages falls off as the frequency goes up.
That may well be more of a factor than the IRF510's in your "much less on the higher bands". I concur with Jerry and did follow Allison's lead that band performance upstairs can be improved by swapping 2N2222 cans for the original pre driver & driver 3904's with resistor halving as suggested.?? I've done that on one board and have been happy. On a separate board, I put in one 2N5109 for each pair of 3904's. That works especially well with 20v on the finals.? I'm getting around 20-25W SSB on 20 meters, and maybe 15 -20 on 80 & 40.?? Ted K3RTA? |
Bob Lunsford
Gerard
Loris Bollina
Ted