Re: 7 MHz Oscillator Ideas
Chuck,
I think we all agree that your design will be plenty stable.
It is crystal controlled, going from zero to 12v on the bias for the varactor that is
in parallel with the crystal can only move the frequency by 2 or 3 khz.
What we are saying is that for most such designs where the varactor might be trying to
give a range of 300khz instead of 3khz, the stability will be 100 times worse than what you experience.
And so it won't work very well unless the power supply that provides the bias across the varactor is well regulated.
You have noted that the capacitance of the varactor does not change much for a 1 volt change in the 12v power supply.
If the bias across the varactor is reduced from 12v to 1v by turning the pot, then a 1 volt change in the 12v supply
will cause a 1/12 volt change in the 1 volt bias across the varactor.
Which doesn't sound like much, but the varactor is much more sensitive to changes in bias voltage at 1v than at 12v.
Jerry, KE7ER
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On Sat, Dec 14, 2019 at 05:49 AM, Chuck Carpenter wrote:
Nick,
I've made some measurements using the?SA612?oscillator in my WWV +?30m receiver.
The crystal is a single, 10 MHz nominal.? Keep in mind that this is a simple DC receiver and may not meet the specs for a $5k buck rig.
I'm using a fairly well regulated bench power supply.? Not a cheap 9V battery that sags quickly under?load.
So are we saying that the DC supply to the receiver is drifting plus and minus several mV?? And that would significantly change the oscillator tuning?
Or is the power supply stable within a few mV?? And that it stays at the set voltage unless deliberately changed.
I'm measuring the oscillator frequency via gimmick with set voltages at 10, 12 and 14. I've measured the output of the 5V regulator to the SA-612 with no significant change at each set voltage.
With both O'scope and DVM?on most sensitive levels, there is no significant DC voltage?ripple.
Yes, the highest?tuned?frequency changes at each of the set voltages.? BUT is doesn't change?once set!
So unless the set voltages are changed, I doubt that anyone, by ear, could detect any change while listening to a specific station, e.g., WWV-10MHz with test RX.
And I have done that with the RX I built, both WWV and CW station on 30 m.
--
Chuck, W5USJ (ex K2OFN)
Point, Rains Co, TX? EM22cv
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Re: 2n2xx Transceiver R.I.P.
Agreed Mike.? Good to hear from you again.? Jim just doesn't want a mass distribution.? Note that he encourages builders to make their "OWN PCB".? I agree that it was an amazing design.? Jim is one of the great designers of qrp gear and a good friend.? Doug, KI6DS
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Re: 2n2xx Transceiver R.I.P.
Rob there is no problem with anyone making their own board for their own use, it is the distribution of those boards that is the thing that I object to.? Jim does not want to not does he have the time to do the support that a distribution of boards would surely cause.? He has made his wishes clear, please respect them.??
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Re: 2n2xx Transceiver R.I.P.
The use of ADE-1 (or SBL-1) diode ring mixers make it possible for the receiver? to have a very large dynamic range.? It also makes it possible for the receiver to suck down the battery much more easily than the usual SA612's. I'm thinking I should build up the receiver core, at least. Looking at the 40m version, I'd build out the RF filter at L5,L8,? and everything between mixers M2 and M1 inclusive.? There is a lot to be learned by studying, simulating, and tinkering with that part of the rig. Nothing special in the audio amp.? Many designs these days would use an op amp and an LM386.? Though Jim's PN2222 amp might be lower distortion than an LM386.? Q20 and all those 1n4148's could be replaced with just an RF gain pot at the antenna. Q20 would be useful for muting if this is to be used with a transmitter. Two channels of an Si5351 could replace the VFO (Q24 through T5) and the RX LO (at X5,Q11).? That's a major win on stability, flexibility, and ease of construction. Assuming you're ok with soiling your analog design with a bunch of digital stuff. The Si5351 VFO can flip to the operating frequency if including a transmitter, doing away with the oscillator, mixer, and filter at X8, M3, and T8.? The entire power amp from Q19 to Q25 could be replaced with many other possible designs.? So building this thing could be very ad-hoc, using what you have,?done step by step.? Lots of kits out there for audio amps and transmit power amps if you want to cheat. The Si5351 could be a module from etherkit, adafruit,?qrplabs, or?the ubitx raduino. No need to demand that Jim come out of retirement to fab a board for you. The 2n22xx has no IC's, should be easy to build ugly or manhatten style.? ? ? VU3JVX shows off a beautiful scratch built uBitx ? ?? /g/BITX20/topic/68158902#73506built by creating copper islands using a 5/16 inch "spot weld drill bit" such as ? ??? Those same bits can be used to create manhatten pads if you press a little harder. >? It seems that he has no problem with copying the design or modifying it, along with creating a pcb. >? Obviously it would be immoral to profit from it.? If somebody wants to make available a 2n22xx kit and is ready to fully support it,? perhaps you should just ask Jim.? He might well be delighted to give his blessing. So long as he doesn't have to answer the phone. Nothing in my rather short list of scruples says you shouldn't be getting paid $5/hr for your efforts. Jerry, KE7ER
On Sat, Dec 14, 2019 at 03:54 AM, Michael Maiorana wrote:
Doug,
From Jim's email on November 10th:
?
Finally, all of the documentation for the 2N2/XX is on my web site:??(??) so you can get the docs, build any of the 3 bands Manhattan-style, like I did originally, or make your own PCB using DipTrace or KiCAD with the changes you see fit (like DDS tuning and Digital Display) on a PCB sized to your liking.
It seems that he has no problem with copying the design or modifying it, along with creating a pcb. Obviously it would be immoral to profit from it.? ?
I remember when I first saw that design and how amazed I was at what he accomplished within the (arbitrary) confines of the contest. Amazing work!
?
Best regards and 73
Mike M?
Ku4qo
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Re: 7 MHz Oscillator Ideas
Nick,
I've made some measurements using the?SA612?oscillator in my WWV +?30m receiver.
The crystal is a single, 10 MHz nominal.? Keep in mind that this is a simple DC receiver and may not meet the specs for a $5k buck rig.
I'm using a fairly well regulated bench power supply.? Not a cheap 9V battery that sags quickly under?load.
So are we saying that the DC supply to the receiver is drifting plus and minus several mV?? And that would significantly change the oscillator tuning?
Or is the power supply stable within a few mV?? And that it stays at the set voltage unless deliberately changed.
I'm measuring the oscillator frequency via gimmick with set voltages at 10, 12 and 14. I've measured the output of the 5V regulator to the SA-612 with no significant change at each set voltage.
With both O'scope and DVM?on most sensitive levels, there is no significant DC voltage?ripple.
Yes, the highest?tuned?frequency changes at each of the set voltages.? BUT is doesn't change?once set!
So unless the set voltages are changed, I doubt that anyone, by ear, could detect any change while listening to a specific station, e.g., WWV-10MHz with test RX.
And I have done that with the RX I built, both WWV and CW station on 30 m.
--
Chuck, W5USJ (ex K2OFN)
Point, Rains Co, TX? EM22cv
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Re: What level math is in the RF design books?
Rob --
If you have a copy of "Experimental Methods of RF Design", take a look at chapter 2 "Amplifier Design Basics", first few pages, which discusses simplified models of semiconductor devices. I think that level of intuition is great to have while building and debugging circuits. It does not have a lot of advanced math.
73
Ram VU3RDD
On Mon, Dec 9, 2019, at 5:47 PM, Rob via Groups.Io wrote:
What level of math course would I need to study to learn how to comprehend the equations presented in
design books like Introduction to Radio Frequency Design?? by? W7ZOI.
I have been tinkering with circuits from these books for 50 years but never really learned what is in the math.
There are all sorts of online math course now so.....
What level of math class would teach this gobbledygoop?
and
Do any of you? ACTUALLY use this level of math to build radios or is the math only used by
the guys designing the transistors????
73 Rob KB3BYT
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Re: 2n2xx Transceiver R.I.P.
Doug, From Jim's email on November 10th:
Finally, all of the documentation for the 2N2/XX is on my web site:??(??) so you can get the docs, build any of the 3 bands Manhattan-style, like I did originally, or make your own PCB using DipTrace or KiCAD with the changes you see fit (like DDS tuning and Digital Display) on a PCB sized to your liking.
It seems that he has no problem with copying the design or modifying it, along with creating a pcb. Obviously it would be immoral to profit from it.?
I remember when I first saw that design and how amazed I was at what he accomplished within the (arbitrary) confines of the contest. Amazing work!
Best regards and 73 Mike M? Ku4qo
On Sat, Dec 14, 2019, 1:03 AM Doug Hendricks < ki6ds1@...> wrote: Rob, the 2N22 is the intellectual property of Jim Kortge.? He has asked that it not be made available.? Please honor his wishes and stop promoting this project.? It would be wrong for anyone to layout their own board and distribute it to anyone.? I would hope that such an idea would NOT be allowed on this list.? Flame suit on.? Doug, KI6DS
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Re: 2n2xx Transceiver R.I.P.
OK..no problem.
My point of view was that it is a well documented
hands on DIY project transceiver
worthy of hand crafting for yourself..... not any
money making ventures....
and since I learned how to kitchen etch PCBs I
have learned much much much more about radio building.
I was not real successful with with my manhatten
radio building.
So when I learned how to take a schematic and
turn it into a PCB in my kitchen I began a steady stream of
very rewarding hobby electronics projects and I
always shared HOW to do this stuff because there is no HEATHKIT
or RADIO SHACK to make it easy to want to play
with the hobby of radio electronics.....
which tends to push newbies into the appliance
operator ...instead of tinkerer... category.....
which leads to addictions like FT8.
On 12/13/2019 08:59 PM, Doug Hendricks
wrote:
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Rob,
the 2N22 is the intellectual property of Jim Kortge.? He has asked
that it not be made available.? Please honor his wishes and stop
promoting this project.? It would be wrong for anyone to layout
their own board and distribute it to anyone.? I would hope that
such an idea would NOT be allowed on this list.? Flame suit on.?
Doug, KI6DS
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Re: 2n2xx Transceiver R.I.P.
Rob, the 2N22 is the intellectual property of Jim Kortge.? He has asked that it not be made available.? Please honor his wishes and stop promoting this project.? It would be wrong for anyone to layout their own board and distribute it to anyone.? I would hope that such an idea would NOT be allowed on this list.? Flame suit on.? Doug, KI6DS
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Re: 2n2xx Transceiver R.I.P.
NO WAY
The project is only dead if you want to leave it
resting.
All of the wealth of documentation is there to
make the 2n2xx tranceiver on ANY base you want... island pads...
manhatten ...
or
PRINT YOUR OWN CIRCUIT BOARDS
which I highly recommend you do because you can
spread out the parts and resize for your own tastes.
There really is no secret here. Use GIMP to draw
black and white line art.
Simply trace all schematic lines with a fat paint
brush and draw all components like you see from a birds eye
view.
here is an example of a PIXIE coming to life:
Etched on kitchen table.
the wet works in more detail here:
and if you MUST have China fabricate a few hundred PCBs for a
massive club build project you can
easily convert YOUR black and white line art to GERBER files.
Have fun.
On 12/13/2019 06:20 PM, Leland L. Bahr
wrote:
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The designer has voiced he does not want to offer a board.? The
project is dead.
Lee, w0vt
On 12/13/2019 3:50 PM, ohwenzelph via
Groups.Io wrote:
i would like (at least) one
jerry aa1of
franconia nh
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The designer has voiced he does not want to offer a board.? The
project is dead.
Lee, w0vt
On 12/13/2019 3:50 PM, ohwenzelph via
Groups.Io wrote:
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i would like (at least) one
jerry aa1of
franconia nh
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i would like (at least) one
jerry aa1of
franconia nh
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Steve, if the Chinese wanted to copy it, they would do it gerbers or no.? If I were the designer, I would be more concerned about having to support the builders if I produced new boards.? One way around this is to put the board on OshPark as a shared pcb.? That way, the gerbers are not downloadable, but are useable by someone who wants to build the project.? This will be more expensive per board than getting a 100 boards built in China, but much more protective.? Dale
On Fri, Dec 13, 2019 at 9:06 AM sigcom1 < sigcom@...> wrote: You can look back through the message subject for the details.
The designer of the 2N2-XX chose not to release the Gerber file for the PCB.
Frankly, I wholeheartedly stand behind his decision.
73.......Steve Smith WB6TNL
"What's the status of this? I would be interested in this as well."
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I cut my gums on 741's and 2222's.? Put down for a couple.? Thanks, Howard, n3fel
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You can look back through the message subject for the details.
The designer of the 2N2-XX chose not to release the Gerber file for the PCB.
Frankly, I wholeheartedly stand behind his decision.
73.......Steve Smith WB6TNL
"What's the status of this? I would be interested in this as well."
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What's the status of this? I would be interested in this as well.
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Re: Anyone Built the Rose 80?
Just keep in mind that the designer put those tuned circuits in for a reason.
He did it so a bunch of spurs would not show up on the air and exceed FCC specs.
Hard to know exactly where they all are and how strong without a spectrum analyzer.
Experimenting to measure power out into a dummy load is perfectly fine.
Going on the air with a 5W transmitter that has some spurs 30dB down
is not encouraged, but they probably wouldn't throw you in jail for very long.
Jerry
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On Thu, Dec 12, 2019 at 09:40 PM, John Roland wrote:
Jerry, This is very helpful, especially your explanation of the right side of T3. ?? I think I'll play with your idea of bypassing T3 and see what it does to the stability of the power out.???
And thanks for the hint about the Private button, never noticed it before.
/John
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Re: Anyone Built the Rose 80?
Jerry, This is very helpful, especially your explanation of the right side of T3. ?? I think I'll play with your idea of bypassing T3 and see what it does to the stability of the power out.???
And thanks for the hint about the Private button, never noticed it before.
/John
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Re: Group Introduction: If you're going to post on the group, reply here!
Thanks for the group and all the effort it takes to moderate a group.
Thank you!
Jim
KF9VV
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Re: Anyone Built the Rose 80?
In my previous post I was wrong about why the secondary of T3 is non-resonant.?
Double tuned RF transformers are quite common in radio gear.
I think on T3 for the Rose-80 with a secondary of only two turns of wire,
it simply has too little inductance to inhibit much of anything at 3.5mhz.
Let's take it to an extreme, bring that frequency down from 3.5mhz to just 60hz.
Those two turns now look like a very short piece of wire,
and the only impedance presented to our 60hz signal is that of the 470pf cap at C44.
The impedance of the cap is far larger than any contribution from the inductor,
to where the inductor has virtually no effect
Jerry
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On Thu, Dec 12, 2019 at 07:15 PM, Jerry Gaffke wrote:
Getting to your primary puzzle, I doubt the right side is trying to be resonant.
The datasheet says the right side only has 2 turns, whereas the left side has 14 turns,
So the inductance is far less, your inductance meter speaks the truth.
I'm guessing the cap at C44 would work about as well if it were 0.1uF instead of 470pf.
Would be an interesting experiment to tack a cap in parallel, see if performance changes.
It does sort of look like a series resonant circuit, so we might think it would not conduct
unless at the resonant frequency.? However, the output of that transformer is a voltage source
with our 3.5mhz sine wave, the 470pf cap at C44 does not see an inductance to interact with.
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Chuck Carpenter
Ramakrishnan Muthukrishnan
Dale Hardin KS4NS
