Re: The new uBITX boards are here
?ordered? 10 of one, 15 of the other.
gordn
toggle quoted message
Show quoted text
?Well I'll be doggoned --- I found BOTH those transistors at mouser.? ?Tonight I'll order some.? ?This is starting to get INTERESTING.
Gordon
What did I say about using a high FT transistor?
Since I don't have KST10s but know the MPSH10s and you say its the same save for package
my first shot would be go for it, can't be worse.? MPSH10s are 650mhz minimum so its better
by two.? Looking at the data sheet make sure the pins for base and emitter fall on the right
pads.? Likely do but, check.
The kst10 FYI is 650mhz FT device so it will likely be better by a factor of two but not as good as
the BFR106 is a 5ghz device.? For feedback amps like that a FT according to the spreadsheet?
needs to be good to more than 2000mhz.? I'd suspect any 1ghz or better device should work well.
when compared to a 300mhz device.? The spreadsheet off the disk EMRFD gives 18db for
a 5ghz device and 13.6db for a 300mhz device and 15.8 for a 650mhz device.? You get
2.3db for he effort.? ?In reality it may be better.?
I have to comment did you check the FT for that device?? For the BFR106?? The idea is
not to flail wildly but to do some basic calculation and the easy one is:
B=Ft/F? where FT is the stated datasheet number and F is the working frequency.
if we take 300 and divide by 45 we get 6.67 a very low gain.? 650/45 is 14/44 better
but barely twice.? Work it backward, a desired gain of 17db or 50 so 45*50=2250
that's the desired FT.? The only thing somewhat magic is that 17db happens to be 50
but that is easily calculated as the antilog.? 17db=10(log50) or for those that want a
weird backward explain...
17db gain is:? 10db or 10x plus 7db or 5x, so we multiply and get 50.
Why use logs (aka? DB)?? it saves multiplying big numbers in your head that you can otherwise add.
The magic is that I can remember the logs of 10 for integers at age 65 but, not what day it is. ;-)
Hint I grew up with and still have a slide rule.? The calc in the iphone is decent in scientific mode
(turn it landscape).
Allison
Allison
|
Re: What does zero-beat sound like?
#ubitx
Rogier
Have you ever tuned across a steady carrier with a CW receiver and listened to the tone
as it starts high (difference between the two signals), then goes lower as you get closer to
the same frequency, and then goes back higher as you move to a higher difference between
signal frequencies?? Near the center of this tuning range the difference signal will go lower
and lower until it becomes less than 1 Hz.? If your receiver has an S-meter you can probably
see the meter waving back and forth at a few tenths of Hz difference.? Continue fine tuning to
minimize this slow frequency difference and you will find a place where there is no difference
between LO+/- BFO and received signal.? That is "Zero-Beat".? I guess the term "zero" means
"no beat note"...maybe...?
Hope that helps. Sometimes us ancient old geezers assume that newer hams already know all the radio language.
Arv? K7HKL
_._
On Tue, May 29, 2018 at 4:14 PM kj6etl < pa1zz@...> wrote: Ok this might be the most newbie queastion in the century but I am not sure what Farhan means in the Tune-Up instructions to calibrate the uBitx to "zero-beat" on a known AM station.
Doest this mean turning for best sound? No sound? A 1000rz tone?
Seriously what is this "zero beat" on an AM broadcast station supposed to sound like ?-)
Thanks!
Rogier
|
What does zero-beat sound like?
#ubitx
Ok this might be the most newbie queastion in the century but I am not sure what Farhan means in the Tune-Up instructions to calibrate the uBitx to "zero-beat" on a known AM station.
Doest this mean turning for best sound? No sound? A 1000rz tone?
Seriously what is this "zero beat" on an AM broadcast station supposed to sound like ?-)
Thanks!
Rogier
|
Re: Need a Customs Form for import of Kees AGC and Pop-Thump kits into Canada. Can anybody let me know off-line?
#ubitx-help
Hi Dana,
The customs form is required for the seller only /Kees/. He has to declare the value of goods imported to Canada.
73, Ted
VE7VIB
|
Any thoughts if these mods will hold if we switch irfs to?RD16HHF1?
|
Re: Oscillation problems Bitx20a
Thank you all for your replies, I appreciate it very much. Yes, dead-bug-style means keeping short leads and I managed to do that. I started this project November last year and took my time building it. I managed to keep everything on a surface area of 5 by 6 inches in two layers of doubled sided copper clad board. The DDS VFO with Arduino (AD7C design) and PA on the top layer. One corner of the PA board is cut out so I can still reach the carrier-pot and variable capacitors on the BFO below. During the process I managed to solder the components closer and closer together.
I used a 12 year old schematic which does not have the Miguel mods but now I know how to apply them, thanks. I use one of those cheap Chinese 1 kHz signal generators and when disconnecting the 9V battery it continous to oscillate. But when disconnecting the aligator clip it stops. I should have thought of that before, it seems the (unshielded) lead to the AF section is causing the feedback.
The PA is set to about 40 mA for the driver bias and both final stages, the drive adjust is a little over half way and that gives me about 5W output. I¡¯m very happy with that for now.
I use a cheap multimeter with only two decimals so in order to get the MOSFETs equal current I feel the heat sinks and adjust a little so they both heat up at about the same rate. Not very scientific but it seems to work. And 5W is good enough for now, next up is the tx/rx switching relay. If all goes well I hope to make my first QSO soon.
Because I made some adjustments along the way, for use on 40 meters, I had to use a different BPF as well. I used a different design for that. That caused a lot of loss in signal on RX (different output impedance of the BPF) but I could compensate for that by using a 100 pF coupling capacitor for C11 instead of the original 10 pF. I hope this will not cause any problems in the long run.
For the low pass filter I used T50-6 toroids and they get quite warm after a couple of minutes of continuous 5W output. I knew these toroids were not ideal for frequencies below 10 MHz but they were all I had at the time. I received a bag of T50-2 toroids recently and I wonder if it is wise to replace the toroids with those, it will be quite a hassle but they have a better Q in the 7 MHz range. But maybe the Q is not that important and they will get hot anyway, any ideas/suggestions about that?
|
Thank you very much Howard & Rowland for speedy reply.??
For R86, do i solder off one end (example below, #2) , lift it up gently?? Solder one side to 33uH/27uH inductor to the R86 removed corner and inductor back to point #2?
? ?R86
?_____
?|? ? ? ? ?|
1? ? ? ? 2
I will try to source the part locally here, I am out in Canada, va3qy.
Sajid
|
Re: Need help understanding a line of code in ubitx_si5351.cpp (msxp2 = ...)
#radiuno
OK, a few more words about what's going on inside the si5351.
Perhaps more than you really want to hear.
Assume you are tuned into a CW station at 7.1mhz.
We have a? single conversion superhet such as the Bitx40, the VFO is 7.1 mhz above
our 12mhz intermediate frequency, so 19.1mhz.? The Si5351 is providing that VFO.
But the Si5351 only has an 875mhz reference oscillator, it has to do some sophisticated math inside
to create that 19.1mhz VFO.? And that math sometimes has rounding errors.
Most of the time the VFO is right at 19.1mhz, but it does occasionally jump around a little bit,?
in extreme cases by a kilohertz or more.? So in addition to letting you hear that 7.1 mhz station,
your radio might also be letting through bits and pieces of other stations at 7.099 or 7.101 mhz, if only?
for a millionth of a second or so.? Those bits and pieces add up, they sound like noise.?
Specifically, phase noise.
To reduce that phase noise requires better computations inside the si5351, and that requires more power.
?
Here's a brief example of the sort of math that goes on inside the Si5351:
Assume we have a 875mhz reference, and want to generate a 19.1mhz signal.
We an get close by dividing by 46, giving 19.0217 mhz out.
We can divide by 45, to get 19.4444 mhz.
If we mostly divide by 46, and sometimes divide by 45, it can average out to exactly 19.1 mhz,
but if you look close you can still tell that it is just jumping between 19.0217 and 19.4444 mhz out.
Some serious phase noise.
This is called a fractional divider, because it is dividing by something between the integers 45 and 46.
That's what SiLabs does, except they also add a programmable delay line to the output pin.
They delay the rising and falling clock edges a few picoseconds, differently for each clock edge,
doing calculations with each clock edge to determine how much delay is needed to make the output
look like a 19.1mhz square wave.? Those calculations aren't perfect, nor is the delay line.?
So we still get some residual phase noise.
The Si5351 operates in two stages, first stage brings the 25mhz crystal oscillator up to around 875mhz.
This involves a second fractional divider much like the one described above.
In this case, 875/25 = 35.0 exactly, but that figure of 875 could have been anything between 600 and 900 mhz.
Jerry
toggle quoted message
Show quoted text
On Tue, May 29, 2018 at 12:29 pm, Terry Morris wrote:
Thanks for your response Jerry, but I am still snowballed.?
|
Re: The new uBITX boards are here
?Well I'll be doggoned --- I found BOTH those transistors at mouser.? ?Tonight I'll order some.? ?This is starting to get INTERESTING.
Gordon
toggle quoted message
Show quoted text
What did I say about using a high FT transistor?
Since I don't have KST10s but know the MPSH10s and you say its the same save for package
my first shot would be go for it, can't be worse.? MPSH10s are 650mhz minimum so its better
by two.? Looking at the data sheet make sure the pins for base and emitter fall on the right
pads.? Likely do but, check.
The kst10 FYI is 650mhz FT device so it will likely be better by a factor of two but not as good as
the BFR106 is a 5ghz device.? For feedback amps like that a FT according to the spreadsheet?
needs to be good to more than 2000mhz.? I'd suspect any 1ghz or better device should work well.
when compared to a 300mhz device.? The spreadsheet off the disk EMRFD gives 18db for
a 5ghz device and 13.6db for a 300mhz device and 15.8 for a 650mhz device.? You get
2.3db for he effort.? ?In reality it may be better.?
I have to comment did you check the FT for that device?? For the BFR106?? The idea is
not to flail wildly but to do some basic calculation and the easy one is:
B=Ft/F? where FT is the stated datasheet number and F is the working frequency.
if we take 300 and divide by 45 we get 6.67 a very low gain.? 650/45 is 14/44 better
but barely twice.? Work it backward, a desired gain of 17db or 50 so 45*50=2250
that's the desired FT.? The only thing somewhat magic is that 17db happens to be 50
but that is easily calculated as the antilog.? 17db=10(log50) or for those that want a
weird backward explain...
17db gain is:? 10db or 10x plus 7db or 5x, so we multiply and get 50.
Why use logs (aka? DB)?? it saves multiplying big numbers in your head that you can otherwise add.
The magic is that I can remember the logs of 10 for integers at age 65 but, not what day it is. ;-)
Hint I grew up with and still have a slide rule.? The calc in the iphone is decent in scientific mode
(turn it landscape).
Allison
Allison
|
Re: The new uBITX boards are here
What did I say about using a high FT transistor?
Since I don't have KST10s but know the MPSH10s and you say its the same save for package
my first shot would be go for it, can't be worse.? MPSH10s are 650mhz minimum so its better
by two.? Looking at the data sheet make sure the pins for base and emitter fall on the right
pads.? Likely do but, check.
The kst10 FYI is 650mhz FT device so it will likely be better by a factor of two but not as good as
the BFR106 is a 5ghz device.? For feedback amps like that a FT according to the spreadsheet?
needs to be good to more than 2000mhz.? I'd suspect any 1ghz or better device should work well.
when compared to a 300mhz device.? The spreadsheet off the disk EMRFD gives 18db for
a 5ghz device and 13.6db for a 300mhz device and 15.8 for a 650mhz device.? You get
2.3db for he effort.? ?In reality it may be better.?
I have to comment did you check the FT for that device?? For the BFR106?? The idea is
not to flail wildly but to do some basic calculation and the easy one is:
B=Ft/F? where FT is the stated datasheet number and F is the working frequency.
if we take 300 and divide by 45 we get 6.67 a very low gain.? 650/45 is 14/44 better
but barely twice.? Work it backward, a desired gain of 17db or 50 so 45*50=2250
that's the desired FT.? The only thing somewhat magic is that 17db happens to be 50
but that is easily calculated as the antilog.? 17db=10(log50) or for those that want a
weird backward explain...
17db gain is:? 10db or 10x plus 7db or 5x, so we multiply and get 50.
Why use logs (aka? DB)?? it saves multiplying big numbers in your head that you can otherwise add.
The magic is that I can remember the logs of 10 for integers at age 65 but, not what day it is. ;-)
Hint I grew up with and still have a slide rule.? The calc in the iphone is decent in scientific mode
(turn it landscape).
Allison
Allison
|
Re: ardurino tutorials and books
You said: "It is apparent that you do not feel this is an honest mistake because you have given yourself the boot in the pants to leave,"
But he said: "I submitted this site for info and help for hams like myself who asked for help learning about ardurinos and no answer. Some who are quick to burn someone for honestly trying to do good ..."
Sounds more like he sees it as an honest mistake to me.
Then you said: "The comment about returning to qrpp cw. Do you think that is punishment?"
But he said: "Anyway I'm gone, sorry for any mistake. Back on the bands with qrpp cw."
I don't see anything in his comment that would make me think he feels like he's being punished.
In a later post you stated: "I have struggled for many years trying to comprehend"
Now *that* I can believe.
Vince.
toggle quoted message
Show quoted text
On 05/29/2018 04:12 PM, Terry Morris wrote: Like what?
Terry - KB8AMZ
On Tue, May 29, 2018 at 3:37 PM, Vince Vielhaber <vev@...
<mailto:vev@...>> wrote:
Terry, you read things in his post that I certainly didn't.
Vince.
Michigan VHF Corp.
--
Michigan VHF Corp.
|
Re: ardurino tutorials and books
toggle quoted message
Show quoted text
On Tue, May 29, 2018 at 3:37 PM, Vince Vielhaber <vev@...> wrote: Terry, you read things in his post that I certainly didn't.
Vince.
? Michigan VHF Corp.? ?? ?
? ? ? ? ? ? ? ? ? ? ? ? ?
|
Re: The new uBITX boards are here
Allison, How about using KST10s for Q10/20? Same as the MPSH10, but surface mount.
Just a suggestion.
Marco - KG5PRT
On Tue, May 29, 2018 at 1:29 PM, ajparent1/KB1GMX <kb1gmx@...> wrote: Farhan,
Look the traces for the final to the output transformer.? Make them wide (low impedance).
same for the gate.?
The interaction between the mosfets and the drivers is both closeness the three toroids try to couple
being very close.? I found that alternating them front and back tamed it so its a space issue.
From the output to kT1 (filter select) get close to the driver and pre driver.? All of the relays in
mine are now wrapped win copper tape and grounded.? Isolation improved and the unwanted
regeneration(TX) is helped.
Running with grounded (and insulated heatsinks) helps also with feedback issues.
The 45mhz amp is tepid, the 2n3904s (q10 and 20 in the V3 schematic) are not doing well at 45mhz?
just the common emitter stage as the emitter followers are fine there.? Changing them to BF106
(handy but other high FT parts should work) brought the stage gain to calculated rather than
about measured 7db.? The 2n3904 is an inexpensive workhorse part but the -3db gain corner
is 15mhz in a 16db feedback amp (TIA helps a tad).
Allison
|
Re: Receive FM Radio Station
#bitx40
Just a wild guess....
There is enough pickup die to leads to hear the station at the input of the 45mhz mixer and?
its second harmonic 90mhz plus DBMs make very good phase detectors (that means
they also can detect frequency changes).? I'd bet you are not far from the station.
IF the input low pass filter is right this should not happen but if you have wire loops?
you can get around the back of the filter.? Shielding is your friend.
FYI I grew up in the shadow of a AM BC station and everything I did picked it up
even ma bells telephones!
Allison
|
Hi need help with the wiring of a bitx40 got to the part where you do the 8 pin on the raddduino board but then it said ti hook up the 5 pin connector?to the board don't bknow if I got the wrong? raduino board or something changed from the picture in the assembly? but I cant find the hook up fot the 5 pin connector my board has all pins on the bottom side
thank you
Adam ka2uol
|
Re: ardurino tutorials and books
Terry, you read things in his post that I certainly didn't.
Vince.
toggle quoted message
Show quoted text
On 05/29/2018 03:08 PM, Terry Morris wrote: David Todd,
You are way overboard on your decision to leave the group. If that is
your decision, then by all means leave. No one in this group told you to
leave or asked you to leave. You decided, yourself, that the group
wanted this. Arv just brought this up as a question. I did not see one
reply that suggested that you leave. Pertaining to the topic in
rebuttal, in my opinion, I prefer to purchase the book that was
published for author so that he/she receives their due reward for
passing on their knowledge. Some knowledge is passed on for free and
some is passed on for monetary exchange.
It is apparent that you do not feel this is an honest mistake because
you have given yourself the boot in the pants to leave,
The comment about returning to qrpp cw. Do you think that is punishment?
"Holly moley Festus, I have been punished by working qrpp cw for the
past 31 years". NOT! I know that you are not a newbie, but if you
persist that you want to leave then, goodbye, but you are welcome back.
Terry - KB8AMZ
Brimfield Twp, OH USA
Linux User# 412308, Ubuntu User# 34905
OSs: LM18.2 64bit, Ubuntu 16.04, tahrPup64 64bit, Raspian
Orgs: PCL70-FOP, NTHS, ALUG, ARRL, PCARS#78, NAQCC#6668, NO-QRP-C,
QRP-ARCI#8855, SKCC#14195, USN 1965-1969 AG3
I chair the PCARS CW/QRP SIG and Linux for Hams SIG, second and fifth
Tuesday
my computer, my opinion
On Mon, May 28, 2018 at 2:40 PM, david todd via Groups.Io
<kg9rb@... <mailto:kg9rb@...>> wrote:
Arv,
I did a Google Search for this site. Maybe I should never tried
being a good guy. If there are problems with the books then google
should not list them. I submitted this site for info and help for
hams like myself who asked for help learning about ardurinos and no
answer. Some who are quick to burn someone for honestly trying to do
good sounds like a left liberal always trying to find something
wrong with the good unless theyhad a hand with it.
Well sorry. I guess I'm not worthy of being on this fourm. I've been
a ham for over 35 years. And in that time I always tried to pass on
good info, suggestions etc to HELP MY FELLOW HAM. im still going to
deal with ashlar by buying several rigs off him and helping
beginning hams get on the air cheap. Obviously you and a few others
don't like someone trying to help. If I did something wrong, I
haven't a clue. If, I guess some books on that site shouldn't be,
then google and others need to ban it.the authors need to have them
removed. Guess no one complains when they download ham radio
e-books or magazines that are offered. I will cancel my account
because this will make u happy. Just another of the many fourms I
belong to. One less won't bother me a bit. Ur attitudes remind me of
the fake witch hunt going on with our great president. Only if it
serves your purposes.
Guess I won't try to help any ham on fourms like this again. Shame I
bet u have the same attitudes towards cbers who try to convert to
ham radio. So quick to ban me for honestly trying to help. No
malice, no slide of hand, no sneaky business.
Yes I will ban myself since the king has spoken, ur probably some
who bicker on this fourm alot. U can have it. I will deal with
ashhar directly by email. You don't control ham radio as a whole.
That is the problem today high do something wrong even by mistake,
ur spied on, banned or excluded.
Wow hey ever thought of emailing me directly and explaining what I
might have supposedly done wrong?
Guess if a noobee was to send too many Cqs while attempting his
first transmission u would make him quit for his outrageous mistake.
I have 4 more rigs to buy and I won't bother anyone here about it.
Shame. We are ashhars customers, not urs.
Anyway I'm gone, sorry for any mistake. Back on the bands with qrpp cw.
Ka9koj
Sent from Yahoo Mail. Get the app
--------------------------------------------
On Sun, 5/27/18, Paul Schumacher via Groups.Io
<wnpauls@... <mailto:[email protected]>> wrote:
Subject: Re: [BITX20] ardurino tutorials and books
To: [email protected] <mailto:[email protected]>
Date: Sunday, May 27, 2018, 4:44 PM
I agree, we should not ban anyone who makes
an honest mistake.
(I would have
been banned a long time ago).
My
college students thinks it is perfectly okay to steal
software, and we
try to guide
them to the right way. (They will be writing software
that theydo not want to be stolen). They just
need to see it differently. It is part ofthe
internet culture that needs work!
Paul K0ZYV
On Sunday, May 27, 2018, 2:23:12 PM
CDT, Roy Appleton <twelveoclockhigh@...
<mailto:twelveoclockhigh@...>> wrote:
No he
should not be banned!
RoyWA0YMH
On Sun, May 27, 2018, 12:06 PM Arv Evans <arvid.evans@...
<mailto:arvid.evans@...>>
wrote:
The message containing that
free book URL has been deleted. Of course that does not
eliminate the message copies
that have already been sent to subscribers. The person
who posted the message seems to
be a relatively new ham, and one who is new to this
group. This situation raises
some questions...should the person who sent the FREE Books
URL be banned from groups.io <>?
?Some of the books on their
list are self-published documents that were probably
rejected
by mainstream publishing
houses. Some obviously originated in countries that do not
have copyright or other
document protection laws. Some are actually advertisements
and
political or personal agendas in the
guise of free books. And a few seem to be copies of
legitimate books. ?
Arv K7HKL
_._
On Sun, May 27, 2018 at 9:33 AM Bo Barry <bobarr@...
<mailto:bobarr@...>>
wrote:
Ain't giving my credit card
number to something that says it's free.
--
Michigan VHF Corp.
|
Re: Need help understanding a line of code in ubitx_si5351.cpp (msxp2 = ...)
#radiuno
Thanks for your response Jerry, but I am still snowballed.
Like I took the Extra Class License class the second time around with the same instructor, Jim Wilson, AC8NT. Jim is a scholarly guy with more degrees than I have HF rigs, sometimes he is very down to earth and speaks in terminology that I understand. I have struggled for many years trying to comprehend the magic with electronics and something is not clicking within my synapses. The other club members in my class told me after various classes that I asked really good questions that they were embarrassed to ask. Whoopie. Not the point. I did ask Jim many questions but the responses were probably geared more for EE grad students than what I comprehended. The others in my class understood the responses so I struggled along until the end of the class. I let Jim know that I didn't understand his responses but I didn't want to hold up the rest of the class. Jim advised me to study the test pool questions but continue the class (the only thing it cost me was time). At the end of the class Jim had a special VE team to test us. I didn't pass. I was more confused than before. My club was giving a scheduled test in 3 weeks, but there was a local hamfest in 2 weeks. I crammed like I was crazy and when I went to take the test I felt crazy. I did pass though. Most of the questions I answered correctly I still don't understand. Now I want to learn more than before how this magic works, I would really like to build a transceiver of my own design and know why the pieces and parts work.
Moving on the next topic...
On Mon, May 28, 2018 at 8:46 PM, Jerry Gaffke via Groups.Io <jgaffke@...> wrote: I have no idea at what point phase noise will be an issue for the si5351 across?
the various modes of operation, be it SSB, CW, FM,? or digital.
I do know that it works to 200mhz, you can push it to almost 300mhz.
Phase noise and resolution of the si5351 will be 10x worse at 200mhz than at 20mhz.?
Bringing on an Si5340 would be a nice handy sledge hammer for prototyping,?
goes up to 1028mhz, resolution of ppb, and has very low jitter.??
Likely cheaper and lower power ways to do what you need, but it's a nice part.
Not many hobbyists are using it, you might be writing your own code, and that could get nasty,
The Si5338 is a bit cheaper, and lower performance.?
But better than the Si5351.
Again, you might be writing your own code.
Both cost a fair bit more than the $1 Si5351, and are surface mount with a bunch of pins.
Jerry
On Mon, May 28, 2018 at 03:21 pm, Terry Morris wrote:
Both the question and the response/answer are intriguing to me. Mostly the answer. I don't comprehend most of the answer but I think I get the gist of it. Regarding the latter part of Jerry's conversation speaking about the Si5338, Si5340, and Si5341 is there any other downside other than the loss of about 1 w at 1.8v? I am presuming from your explanation of these devices that there is a positive advantage to using them, not only for 2 meter capability, but for better phase noise suppression and better crosstalk reduction. In an example that I might understand better, would using any of those 3 devices be like the performance difference between an analogue HW-9 and any of the modern commercial transceivers?
|
Re: ND6T AGC implementation for uBIT-X
Thank you Kees.? Envelope arrived in Vermont this afternoon safe
and sound.
73 de Vince N1VIN
On 5/26/2018 12:56 PM, Kees T wrote:
toggle quoted message
Show quoted text
|
Re: ardurino tutorials and books
David Todd,
You are way overboard on your decision to leave the group. If that is your decision, then by all means leave. No one in this group told you to leave or asked you to leave. You decided, yourself, that the group wanted this. Arv just brought this up as a question. I did not see one reply?that suggested that you leave. Pertaining to the topic in rebuttal, in my opinion, I prefer to purchase the book that was published for author so that he/she receives their due reward for passing on their knowledge. Some knowledge is passed on for free and some is passed on for monetary exchange.
It is apparent that you do not feel this is an honest mistake because you have given yourself the boot in the pants to leave,
The comment about returning to qrpp cw. Do you think that is punishment? "Holly moley Festus, I have been punished by working qrpp cw for the past 31 years". NOT! I know that you are not a newbie, but if you persist that you want to leave then, goodbye, but you are welcome back.
On Mon, May 28, 2018 at 2:40 PM, david todd via Groups.Io <kg9rb@...> wrote: Arv,
I did a Google Search for this site. Maybe I should never tried being a good guy. If there are problems with the books then google should not list them. I submitted this site for info and help for hams like myself who asked for help learning about ardurinos and no answer. Some who are quick to burn someone for honestly trying to do good sounds like a left liberal always trying to find something wrong with the good unless theyhad a hand with it.
Well sorry. I guess I'm not worthy of being on this fourm. I've been a ham for over 35 years. And in that time I always tried to pass on good info, suggestions etc to HELP MY FELLOW HAM. im still going to deal with ashlar by buying several rigs off him and helping beginning hams get on the air cheap. Obviously you and a few others don't like someone trying to help. If I did something wrong, I haven't a clue. If, I guess some books on that site shouldn't be, then google and others need to ban it.the authors need to have them removed.? Guess no one complains when they download ham radio e-books or magazines that are offered. I will cancel my account because this will make u happy. Just another of the many fourms I belong to. One less won't bother me a bit. Ur attitudes remind me of the fake witch hunt going on with our great president. Only if it serves your purposes.
Guess I won't try to help any ham on fourms like this again. Shame I bet u have the same attitudes towards cbers who try to convert to ham radio. So quick to ban me for honestly trying to help. No malice, no slide of hand, no sneaky business.
Yes I will ban myself since the king has spoken, ur probably some who bicker on this fourm alot. U can have it. I will deal with ashhar directly by email. You don't control ham radio as a whole. That is the problem today high do something wrong even by mistake, ur spied on, banned or excluded.
Wow hey ever thought of emailing me directly and explaining what I might have supposedly done wrong?
Guess if a noobee was to send too many Cqs while attempting his first transmission u would make him quit for his outrageous mistake.
I have 4 more rigs to buy and I won't bother anyone here about it. Shame. We are ashhars customers, not urs.
Anyway I'm gone, sorry for any mistake. Back on the bands with qrpp cw.
Ka9koj
Sent from Yahoo Mail. Get the app
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On Sun, 5/27/18, Paul Schumacher via Groups.Io <wnpauls=[email protected]> wrote:
?Subject: Re: [BITX20] ardurino tutorials and books
?To: [email protected]
?Date: Sunday, May 27, 2018, 4:44 PM
?
? ? ? ? ? ? ?I agree, we should not ban anyone who makes
?an honest mistake.
?(I would have
?been banned a long time ago).?
?My
?college students thinks it is perfectly okay to steal
?software, and we
?try to guide
?them? to the right way.? (They will be writing software
?that theydo not want to be stolen).? They just
?need to see it differently.? It is part ofthe
?internet? culture that needs work!
?Paul K0ZYV
? ? ? ? ? ? ? ? ? ? ? ? ?On Sunday, May 27, 2018, 2:23:12 PM
?CDT, Roy Appleton < twelveoclockhigh@...> wrote:
? ? ? ? ? ? ? ? ? ? ?No he
?should not be banned!
?RoyWA0YMH
?On Sun, May 27, 2018, 12:06 PM Arv Evans < arvid.evans@...>
?wrote:
?The message containing that
?free book URL has been deleted.? Of course that does not
?eliminate the message copies
?that have already been sent to subscribers.? The person
?who posted the message seems to
?be a relatively new ham, and one who is new to this
?group.? This situation raises
?some questions...should the person who sent the FREE Books
?URL be banned from ??
??Some of the books on their
?list are self-published documents that were probably
?rejected
?by mainstream publishing
?houses.? Some obviously originated in countries that do not
?have copyright or other
?document protection laws.? Some are actually advertisements
?and
?political or personal agendas in the
?guise of free books.? And a few seem to be copies of
?legitimate books.? ?
?Arv? K7HKL
?_._
?On Sun, May 27, 2018 at 9:33 AM Bo Barry < bobarr@...>
?wrote:
?Ain't giving my credit card
?number to something that says it's free.
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Re: The new uBITX boards are here
Jerry,
The problem is the input impedance is the aggregate of the Miller and fixed (gate capacitance).
That means two things, it changes with voltage and power out (voltage swing at the drain)
and frequency.? It appears with a phase and magnitude different than base low frequency
capacitance.? So its best to force a low input impedance with both feedback and? R-L loading.
The other is some datasheet have the gate capacitance as 135PF and others around 180.
Add to that the effect of some 20pf gate to drain which is part of the miller capacitance its
like driving a load that fights back out of phase.??If you work the parameters for the
RD16HHF the gate is fairly capacitive but shows as 20-j89.4 (looks inductive on the
smith chart) ohms as a result of Miller feed back. [Back of the napkin puts it around 200++pf.]
So keeping the input at low impedance?is a stability issue as lower input impedance
reduces the impact of Miller capacitance.? This is also common with high end LDMOS
devices, nature of the beast.? They are not high impedance input save for at DC.
So a feed impedance of around 50 ohms is maybe high but higher will be troublesome.
Again what works at 40M is likely problematic at 20M and up.? These things have
more gain than given credit when matched.
So In all cases what you want is to drive volts of RF across a low impedance load as
its more stable load for the driver with frequency and also lowers the feedback related
stability.? Some cases some series R on the gate 1-2 ohms helps (see RD16hhf datasheet
for test circuit).? ?I had to do that with my IRF510 (4x4 push pull at 6M) a,mp to calm ot down
each fet having a 2.2ohms smt resistor from the gate pad to the device lead trimmed 1/10th
inch long?from the case.? I was getting 16DB of gain at 6M (and 220W at 30V)!??
A simple test is feed RF into the output and look at the input for S12 (reverse transfer).
If the reverse is -20db and the gain is +13 you have 7db margin before you running a
power oscillator.? You want a much larger margin of possible.? ?The other is to test
the driver with a hand made load say 180PF cap and some calculated resistance
in parallel in place of the fet and watch what the driver does.? I've seen them take
off into reactive loads.?
I also have experience driving MOSFETS for class D and Class E and at 13.56mhz to get
a GAN fet to switch hard I used an IXyS driver that could push 6V at 9A into the gate
and out of the gate (basically charge and discharge a 200pf cap!) to get the nanosecond
switching time the part can do.
Not much different than running 60ma of grid current on a 813 (hollow state thermo fet).
Allison
|
kj6etl
Terry Morris