Feel free to add information to the wiki or make edits as needed. Please respect the work of others by adding your own content rather than editing or removing someone else's content unless doing things like updating URL's etc.?
|
Re: What level math is in the RF design books?
two CR2032 batteries Roy WA0YMH
By
Roy Appleton
·
#389
·
|
|
Re: What level math is in the RF design books?
William, Oooops, That should have been Vrms ?^2 I never could get comfortable with RPN.? I had one of the TI programmables.?That worked good for me for a while.? I *loaned* it to my son when he
By
Chuck Carpenter
·
#388
·
|
|
Re: What level math is in the RF design books?
Chuck, Thanks! I had discovered that a long time ago and was using it in my previous message to illustrate my relative Business Administration degree ignorance of electronic theory. But, coincident
By
k6whp
·
#387
·
|
|
Re: 7 MHz Oscillator Ideas
Here's a thought on a minimalist si5351 vfo: Could turn on a second channel at 600 hz away from the primary channel, weakly coupled into that primary channel. This should come through on most
By
Jerry Gaffke
·
#386
·
|
|
Re: 7 MHz Oscillator Ideas
The si5351 is a great part, and only costs $1. You do need a processor to communicate with the si5351 via its i2c bus, but a low end msp430 these days is $0.50. With that, a 25mhz reference crystal,
By
Jerry Gaffke
·
#385
·
|
|
Re: 7 MHz Oscillator Ideas
It is stable enough because of the use of the crystals. However, if this was an LC circuit, you definitely want voltage into that pot to be regulated. The voltage applied to the diode is always some
By
Jerry Gaffke
·
#384
·
|
|
Re: 7 MHz Oscillator Ideas
Jerry, The capacitance beyond 10V changes very little.? The plotted curves by k7qo?in the attached chart show that. The MV209 is similar to the BB910 that I used. Note too that the curve for the
By
Chuck Carpenter
·
#383
·
|
|
Re: 7 MHz Oscillator Ideas
Would it be of any value to use a Si5351 module like the Adafruit module ($7 from them or Mouser or Digikey) or a homebrew one like VK3PE makes that is a drop in replacement for the Adafruit
By
Jim Pruitt WA7DUY
·
#382
·
|
|
Re: What level math is in the RF design books?
William, Try this:? Vrms = 0.3535 * Vpp? then, Po = Vrms*2 / 100 That's the simplest approximation. -- Chuck, W5USJ (ex K2OFN) Point, Rains Co, TX? EM22cv
By
Chuck Carpenter
·
#381
·
|
|
Re: 7 MHz Oscillator Ideas
Thanks Chuck
By
JT Croteau <jt.tobit@...>
·
#380
·
|
|
Re: 7 MHz Oscillator Ideas
Would not be an issue with the tuning range limited to 3khz.. However, the frequency determining pot for the varactor diode is operating directly from the power supply.
By
Jerry Gaffke
·
#379
·
|
|
Re: 7 MHz Oscillator Ideas
this is the vfo I made from Solid State Design
By
Chris
·
#378
·
|
|
Re: 7 MHz Oscillator Ideas
I built a simple regenerative receiver awhile ago using VK3YE design Rob mentioned and linked http://www.learnmorsecode.com/716/index.html Stable, sensitive.? Two transistors, a resonator, and an
By
Curt
·
#377
·
|
|
Re: 7 MHz Oscillator Ideas
Tried to add two attachments at a time --- Didn't work...8^( -- Chuck, W5USJ (ex K2OFN) Point, Rains Co, TX? EM22cv
By
Chuck Carpenter
·
#376
·
|
|
Re: 7 MHz Oscillator Ideas
Jerry, I get about 3 kHz with a pair of crystals on 7MHz using the "fixture" in the picture.? I measured that with a 10V tuning range. The SA612?oscillator is running from the 6V regulator circuit
By
Chuck Carpenter
·
#375
·
|
|
Re: What level math is in the RF design books?
Rob, I would say a couple terms into a calculus sequence for that equation to lose its mystery. So by the end of a freshman year for an engineering student. There is some physics there too, a math
By
Jerry Gaffke
·
#374
·
|
|
Re: What level math is in the RF design books?
I am a 60 year old retired computer programmer......... with failing vision. I have written software for everything from tiny microcontrollers to track satellites with DOS computers to IBM mainframes
By
Rob <roomberg@...>
·
#373
·
|
|
Re: What level math is in the RF design books?
Rob, Ouch! That's going to leave a mark! It's a fair cop, as the Brit villains say. I went through college begging for a grade in calculus, retired two years ago and *finally* started to do some of
By
k6whp
·
#372
·
|
|
Re: What level math is in the RF design books?
And while I'm at it, I'll recommend two other books: The Art of Electronics, Horowitz and Hill. A classic RF Circuit Design, Chris Boswick. Lots of practical design info and exercises Eric KE6US
By
Eric KE6US <eric.csuf@...>
·
#371
·
|
|
Re: What level math is in the RF design books?
About 15 years ago, I had a website appropriately called KE6US.com. I actually reviewed both EMRFD and Intro to RF Design. Wes was kind enough to send me a thank you email for the reviews.
By
Eric KE6US <eric.csuf@...>
·
#370
·
|