Varactor Diode C Measurement
For my own amazement, measured for comparison two diodes, MVAM109 and BB910.
A schematic of the N5IB design?test fixture** is attached. All stabilized at room temperature for measurement.
?????????????? Capacitance, pF
V??????? MVAM 109????? BB910
0????????? 750????????????????? 52
1????????? 481????????????????? 35
2????????? 340????????????????? 27
3????????? 234??????????????? 22
4????????? 152????????????????? 17
5????????? 100????????????????? 13
6????????? 66??????????????????? 9
7???????? 45??????????????????? 7
8???????? 33??????????????????? 6
9???????? 27????????????????????5.9
10?????? 23???????????????? 5.73
11?????? 21?????????????????? 5.59
12?????? 20?????????????????? 5.45
Highest voltage available from the battery.
The capacitance range of the BB910 is similar to the 60 pF section of a polycon often used with HF?VXOs. The MV-209 has a comparable C range.
** N5IB produced a kit of the fixture, since retired.? Fairly easy to build one from?parts on-hand.
--
Chuck, W5USJ (ex K2OFN)
Point, Rains Co, TX? EM22cv
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Re: 2n2xx Transceiver R.I.P. ADE-1-24 specifications
THANK YOU
KB3BYT
On 12/15/2019 01:38 PM, Jerry Gaffke
via Groups.Io wrote:
toggle quoted message
Show quoted text
That bitx20 thread
on the ADE-1-24 is rather confusing.
And to some extent, so is the ADE-1 datasheet:
? ??
The ADE-1 pins are numbered like a DIP IC, pins 1,2,3 down one
side and 4,5,6
going up the other side as shown in the top left of page 1 of the
data sheet.
Looking at the schematic diagram in the lower right of page 1,
pins L, I, R (local oscillator input, IF output, and RF input) are
at pins 6,2,3 respectively.
We're assuming here that this is a receiver, with the RF coming in
getting converted to the IF.
The three pins shown as grounds are not internally connected.
The bottom of the L coil is pin 1, the bottom of the R coil is 4,
and the pin on the other side of the diode bridge from I is pin 5.
There is no connection (other than magnetic fields) between the L,
I, and R sections.
I think this forum post spells out the final consensus:
? ? ? ?/g/BITX20/message/54143
The only difference found in the ADE-1-24 from the standard ADE-1
is that pins 2 and 5 have been reversed.? Most of us would never
notice.
But if you have an ADE-1-24 and you want it to work *exactly* like
an ADE-1,
you should probably swap pins 2 and 5.
As they note in the forum, grounding pin 5 as shown for the
standard ADE-1
(pin 5 is the center tap of the transformer whose other winding is
L)
may cause less leakage from L (the local oscillator) into I (out
to the intermediate frequency amp).? ?
Dropping an ADE-1-24 into pads designed for an ADE-1 would reverse
this,
favoring the RF port for maximum isolation from the local
oscillator.?
Just looking at the schematic drawing in the datasheet, the L and
R ports appear interchangeable.
However, the datasheet shows significantly better numbers for SWR
looking into the R port than the L port.
?
The ADE-1 datasheet says that the L and R ports are good from 0.5
to 500 mhz,
The I port however, is good from DC to 500 mhz, since there is no
need for
magnetic coupling from the diodes where the mixing occurs out to
pins 2 and 5.
So, for example, if used as the final mixer in a receiver, make
sure the audio is
coming out of the I port.? Other than this, all three ports are
mostly interchangeable.
Jerry, KE7ER
On Sun, Dec 15, 2019 at 06:23 AM, Jerry Gaffke wrote:
Looks like they were made by MiniCircuits as a custom
build for a customer in 2006:
? ??/g/BITX20/topic/4104916#17354
Other posts in that thread indicate that they are pretty much
identical to a standard ADE-1
but the pins got wired up a little bit different.
My guess is that somebody built a few thousand PC boards for the
ADE-1,
and then realized they could get better performance with the
ports wired up differently.
Jerry
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Re: Plug and Play Receiver
Howard,
On second thought, your modules could be a fine way to teach radio.
Modules start to make a lot of sense as radios become more complex.
Many who design radios for a career have created their own modules to play with new concepts.
As you suggested, a DC receiver could be busted down some.
Perhaps demo a very simple diode detector with hi-z phones for local AM stations..
Then a bare bones SA612 (with 9v battery, coil+cap for LO, hi-Z phones, wire antenna).
An inductor tuned with a brass screw for the LO is cheap and approachable.
Same rig could hear your 40m transmission by adjusting the LO coil and cap.
Then add an audio amp, RF gain pot on the antenna, audio gain pot, RF filter,
RF amp, AF filter, a back-to-back diode audio limiter, a stable si5351 vfo.
From there, perhaps a second SA612 and a crystal IF filter, agc,? audio into an RPi.
Spend the remainder of the hour showing how to code DSP algorithms in python.
I might want to play with all that once you're done with it.
Jerry, KE7ER
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On Sun, Dec 8, 2019 at 08:12 PM, Jerry Gaffke wrote:
If you are designing "modules" to make building a receiver easier, I guess that's an SA612 and an LM386?
that get plugged together like two lego blocks.? I'm not so sure I see much point in that.
I'd tend to just give them an etched PC board and a sack of parts.?
On Sun, Dec 8, 2019 at 06:34 PM, n3fel@... wrote:
Jerry, Just a coincidence but I've also been searching for an interesting project for young builders to tinker with radio circuits.? AA7EE's receiver sketch might serve the purpose.? Would there be any interest in this group to move this design to plug and play modules that when implemented would result in a functioning 40m receiver?? The target audience would be kids in the 8-13 yr range.?? Best to center the operating frequency on ARRL's W1AW broadcasts at 7.0475 MHz.? If not this radio, any suggestions?? Must be cheap and reproducible.? By the way, have a browse through the local dollar store where you will occasionally find really affordable electronic stuff.? I recently snagged a few of their powered speaker modules that could easily amplify the HiPerMite headphone output to comfortable desk-top audio.? Howard, n3fel
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Re: 2n2xx Transceiver R.I.P.
That bitx20 thread on the ADE-1-24 is rather confusing. And to some extent, so is the ADE-1 datasheet: ? ?? The ADE-1 pins are numbered like a DIP IC, pins 1,2,3 down one side and 4,5,6 going up the other side as shown in the top left of page 1 of the data sheet. Looking at the schematic diagram in the lower right of page 1, pins L, I, R (local oscillator input, IF output, and RF input) are at pins 6,2,3 respectively. We're assuming here that this is a receiver, with the RF coming in getting converted to the IF. The three pins shown as grounds are not internally connected. The bottom of the L coil is pin 1, the bottom of the R coil is 4, and the pin on the other side of the diode bridge from I is pin 5. There is no connection (other than magnetic fields) between the L, I, and R sections. I think this forum post spells out the final consensus: ? ? ? ? /g/BITX20/message/54143The only difference found in the ADE-1-24 from the standard ADE-1 is that pins 2 and 5 have been reversed.? Most of us would never notice. But if you have an ADE-1-24 and you want it to work *exactly* like an ADE-1, you should probably swap pins 2 and 5. As they note in the forum, grounding pin 5 as shown for the standard ADE-1 (pin 5 is the center tap of the transformer whose other winding is L) may cause less leakage from L (the local oscillator) into I (out to the intermediate frequency amp).? ? Dropping an ADE-1-24 into pads designed for an ADE-1 would reverse this, favoring the RF port for maximum isolation from the local oscillator.? Just looking at the schematic drawing in the datasheet, the L and R ports appear interchangeable. However, the datasheet shows significantly better numbers for SWR looking into the R port than the L port. ? The ADE-1 datasheet says that the L and R ports are good from 0.5 to 500 mhz, The I port however, is good from DC to 500 mhz, since there is no need for magnetic coupling from the diodes where the mixing occurs out to pins 2 and 5. So, for example, if used as the final mixer in a receiver, make sure the audio is coming out of the I port.? Other than this, all three ports are mostly interchangeable. Jerry, KE7ER
On Sun, Dec 15, 2019 at 06:23 AM, Jerry Gaffke wrote:
Looks like they were made by MiniCircuits as a custom build for a customer in 2006:
? ??/g/BITX20/topic/4104916#17354
Other posts in that thread indicate that they are pretty much identical to a standard ADE-1
but the pins got wired up a little bit different.
My guess is that somebody built a few thousand PC boards for the ADE-1,
and then realized they could get better performance with the ports wired up differently.
Jerry
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Re: 2n2xx Transceiver R.I.P.
Primary attraction of this rig is the "back to basics" analog design,
nothing hidden in IC's.
An LM386 for the audio amp is simple, works from 5-15 volts, but is not for the audiophile.
From wikipedia:? "The LM386 was invented by Ernie Leroy Long at Motorola in 1969. It was originally for part of a fuel injection system for a Ford Car."
If true, that makes it 7 years younger than the 2n2222.?
Here's an interesting look at a future proof replacement:??
Many similar analog audio IC's have become obsolete as the?industry moves on to class D switching amps.
But those new amps can create RF hash.
Fiddling with caps in a crystal ladder filter works to adjust bandwidth,
but I assume that the passband shape does not remain optimal.
Also, the extra cruft can add leakage around the filter, impacting the stopband.
Lots and lots of parts if you build something like the 2n22xx with all discrete devices.
If you are buying by the reel, they are very nearly free.
Jerry, KE7ER
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On Sun, Dec 15, 2019 at 06:46 AM, Michael Maiorana wrote:
They made some substitutions, like replacing the discrete?mixers with ADE-1 mixers. I am curious as to why Norcal kept the audio amp the way they did instead of going to a simpler integrated amp. Any ideas? They also did away with the variable bandwidth IF filter.?
?
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Re: 2n2xx Transceiver R.I.P.
Thanks Jerry.?
I spent some time this morning looking at the different versions of this rig, from the original to the Norcal version. The first thing that struck me was how crowded and complex the Norcal board looks when built. I'm sure they spent a tremendous amount of time with the redesign and layout of that board. Not for the faint of heart.?
They made some substitutions, like replacing the discrete?mixers with ADE-1 mixers. I am curious as to why Norcal kept the audio amp the way they did instead of going to a simpler integrated amp. Any ideas? They also did away with the variable bandwidth IF filter.?
I thought?it might be fun to lay out the receiver section using mostly surface mount parts. Not necessarily to get it smaller, but instead to make it less congested.?
I bought a couple of the Si5351 boards from Ebay. I could use those as the VFO, with plans to go to a more elegant (lower power) solution later.
This sounds fun, but maybe it's just because I had too much coffee this morning. I'll start adding things to Kicad and see where I end up.?
Best regards and 73 Mike Maiorana KU4QO
On Sat, Dec 14, 2019 at 7:20 PM Jerry Gaffke via Groups.Io <jgaffke= [email protected]> wrote: The Raduino used on the uBitx consists entirely of a 5v regulator, an Arduino Nano clone, an Si5351, and a standard 16x2 LCD with backlight.
Power consumption is 40ma without the display, the display (mostly the backlight) sucks another 20ma.
? ??/g/BITX20/message/52886
The linear regulator is typically powered from the main 12v supply, so that Raduino heats the room with 60ma*12v = 0.72 Watts.
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Re: 2n2xx Transceiver R.I.P.
Looks like they were made by MiniCircuits as a custom build for a customer in 2006: ? ?? /g/BITX20/topic/4104916#17354Other posts in that thread indicate that they are pretty much identical to a standard ADE-1 but the pins got wired up a little bit different. My guess is that somebody built a few thousand PC boards for the ADE-1, and then realized they could get better performance with the ports wired up differently. Jerry
On Sat, Dec 14, 2019 at 10:00 PM, n3fel@... wrote:
I am curious as to the possible substitution of the mini circuits ADE-1 with imported ADE-1-24 devices.? The look of the two seemed to be identical.? Has anyone found success with the latter?? ?How¨¤rd, n3fel
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Re: 7 MHz Oscillator Ideas
OK, last time, I promise.
Jerry and All,
I?expect we've been thinking grapefruit and tangerines...related but not the same...8^)
Varactors used to tune an entire?AM or FM band?with a max C of 350pF or so and a min C of about 30pF at 12 V. I'd expect them to be like you described.
The varactors I'm using, BB910 or MV209,?have a max C of about 60pF or so and a min C of about 6pF at 12 V, same percentages but minimal effect in the circuit where used.? My choice of these two (or other similar) was related to the 60pF section of a polycon variable often used?in VXOs.
Anyway, Fun Stuff...
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On Sat, Dec 14, 2019 at 09:14 AM, Jerry Gaffke wrote:
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.
? -- Chuck, W5USJ (ex K2OFN) Point, Rains Co, TX? EM22cv
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Re: 2n2xx Transceiver R.I.P.
I am curious as to the possible substitution of the mini circuits ADE-1 with imported ADE-1-24 devices.? The look of the two seemed to be identical.? Has anyone found success with the latter?? ?How¨¤rd, n3fel
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Re: 2n2xx Transceiver R.I.P.
The Raduino used on the uBitx consists entirely of a 5v regulator, an Arduino Nano clone, an Si5351, and a standard 16x2 LCD with backlight. Power consumption is 40ma without the display, the display (mostly the backlight) sucks another 20ma. ? ?? /g/BITX20/message/52886The linear regulator is typically powered from the main 12v supply, so that Raduino heats the room with 60ma*12v = 0.72 Watts. From table 3 of the datasheet ? ?? the Si5351 with all three outputs running typically draws 22ma, this could be either a 2.5 or 3.3v rail.? So as little as 0.022*2.5v=0.055 Watts if powered from an efficient buck mode switcher. The switcher might be 90% efficient, but we don't need all 3 outputs of the Si5351. The switcher would also have to be extremely quiet, but that is possible to do. Most designs just use a linear regulator. Those Nano clones are not a good choice if going for minimum power. And the display does not need to leave the backlight on much, not at all if reflective. A well done microcontroller plus display could be down in the microamps, And you don't really need the display at all: ? ?? /g/qrptech/message/386So the Si5351 is the power hog in the VFO. A bigger power hit on receive for anything based on the 2n22xx is all that analog stuff in the IF, hard to get around it if you want the dynamic range that the 2n22xx has to offer. If you don't feel a need for the dynamic range (or a need to tinker with a good basic analog design), you may as well build another SA612 rig. The ADE-1 is $3 each (in 100's), the toroids $0.20, an Si5351 $1, PN2222's $0.02, crystals $0.20. Lots of $0.02 parts, but this could be kitted up cheaply.
Supporting the 2n22xx took a year out of his life, he's not keen to repeat that.
Reading that closely, I see nothing suggesting he would object to somebody
kitting something?similar to the 2n22xx but different enough (vfo and pa?) that
he can claim to?no longer be the designer.? Worth asking.? We could offer
a filter for his email that discards anything from qrptech forum members.
Doug might be able to enlighten us further on what Jim might think.
If anybody is serious about proceeding.? (I am not.)
Jerry, KE7ER
On Sat, Dec 14, 2019 at 03:00 PM, Michael Maiorana wrote:
On Sat, Dec 14, 2019, 11:43 AM Jerry Gaffke via Groups.Io <jgaffke= [email protected]> wrote:
Nothing in my rather short list of scruples says you shouldn't be getting paid $5/hr for your efforts.
Jerry, KE7ER
?
Ack! Not me! I have a day job :)
?
Do you know what the power supply current requirements would be for the synthesizer, LCD and Arduino? I still marvel at my SW40+ that uses only 25mA on receive.
?
I think it would be fun to build this up with modules. Each module / function would be fairly easy dead-bug style, then connect the bits and test.?
?
Mike M
Ku4qo
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Re: 2n2xx Transceiver R.I.P.
On Sat, Dec 14, 2019, 11:43 AM Jerry Gaffke via Groups.Io <jgaffke= [email protected]> wrote:
Nothing in my rather short list of scruples says you shouldn't be getting paid $5/hr for your efforts.
Jerry, KE7ER
Ack! Not me! I have a day job :)
Do you know what the power supply current requirements would be for the synthesizer, LCD and Arduino? I still marvel at my SW40+ that uses only 25mA on receive.
I think it would be fun to build this up with modules. Each module / function would be fairly easy dead-bug style, then connect the bits and test.?
Mike M Ku4qo
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|
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Re: What level math is in the RF design books?
thank you
On 12/14/2019 08:00 AM, Ramakrishnan
Muthukrishnan wrote:
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Show quoted text
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.
I can see where Jim would rather not have us copy his gerbers,
Hundreds of folks will know that he did the design, and a few
will inevitably pester him for help.?
If stealing a significant part of the design such as the receiver core?
but putting in an si5351, different audio amp, different final,?
he may or may not be ok with that.? Ask.
Borrowing the topology of an especially nice IF stage in your new design,
that sort of thing is often done without any atrribution.
A slippery slope.
And a very compelling design, especially in this age of designs
mostly locked down in DSP firmware.
Jerry, KE7ER
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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
|
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
Attachments:
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Chuck Carpenter
Ramakrishnan Muthukrishnan