Oscillator AGC supply voltage sensitivity

Started by Clifford Heath in sci.electronics.design8 years ago 9 replies

I've built the following circuit for an HF oscillator (though it should work ok at VHF too), but the bias for the output make the AGC very...

I've built the following circuit for an HF oscillator (though it should work ok at VHF too), but the bias for the output make the AGC very dependent on supply voltage. Without adding more silicon, how would you make this work over a wider supply voltage range, say 2.6-4V? Two files below - the circuit, and ca3000.lib, with --- CUT HERE --- Clifford Heath. --- CUT HERE --- Versio...


Negative Cap Clapp oscillator

Started by bitrex in sci.electronics.design2 years ago 1 reply

If you massage this old bus-terminator speeder-upper negative capacitance idea: into a Clapp oscillator topology you get the Negative...

If you massage this old bus-terminator speeder-upper negative capacitance idea: into a Clapp oscillator topology you get the Negative Cap Clapp which sounds like a very bad type of venereal disease to get. It makes even low-Q coils ring just set the R looking into the negative C about equal to the E


Oscillator running on home made thermocouple

Started by Jan Panteltje in sci.electronics.design9 years ago 10 replies

Oscillator running on home made thermocouple: http://www.youtube.com/watch?v=yu0IXX6OXtY&feature=youtu.be I did some transformer winding and...

Oscillator running on home made thermocouple: http://www.youtube.com/watch?v=yu0IXX6OXtY&feature=youtu.be I did some transformer winding and some soldering. The thermocouple is made with simple resistance wire (conrad 543-074-12) 100 Ohm / meter, soldered against normal coper transformer wire. this makes a type 'T' thermocouple, although my calculation show it should then give 18.342767 m...


How to make a Voltage Controlled Oscillator

Started by Cem Uzunoglu in sci.electronics.design8 years ago 122 replies

Hello all, What is the simplest VCO that can be done with off-the-shelf components? It doesn't have to be very fast. Audio range is...

Hello all, What is the simplest VCO that can be done with off-the-shelf components? It doesn't have to be very fast. Audio range is fine. Cheers, Cem


Efratom rubidium oscillator manual

Started by John Larkin in sci.electronics.design11 years ago 10 replies

ftp://jjlarkin.lmi.net/Efratom.pdf

ftp://jjlarkin.lmi.net/Efratom.pdf


Trying to remember IC name

Started by bitrex in sci.electronics.design8 years ago 11 replies

I'm trying to remember the name of a certain IC. I believe it was a PLL-type frequency synthesizer IC for AM/FM radios, to be used with an...

I'm trying to remember the name of a certain IC. I believe it was a PLL-type frequency synthesizer IC for AM/FM radios, to be used with an external local oscillator. I'm fairly certain it had the prefix SA-something, so it was a former Signetics chip. I don't think it's still in production by NXP, though. Any ideas?


Boost Dieing AA

Started by BeeJ in sci.electronics.design9 years ago 7 replies

Looking for that circuit that boosts very low voltages, around 0.3VDC, up to 3 to 5 VDC. The circuit used a germanium transistor in an...

Looking for that circuit that boosts very low voltages, around 0.3VDC, up to 3 to 5 VDC. The circuit used a germanium transistor in an oscillator configuration to do it. Anybody know where to find the circuit?


Best way to remove DC offset ?

Started by Anonymous in sci.electronics.design4 years ago 9 replies

Could some electronics guru please help ? The SPICE simulation for a 50 MHz Colpitts oscillator has a 1.5 V DC offset. What would be the best...

Could some electronics guru please help ? The SPICE simulation for a 50 MHz Colpitts oscillator has a 1.5 V DC offset. What would be the best way to filter it out ? AC coupling capacitors are not useful because of capacitive reactance. Any hints amd/or suggestions would be helpful. Thanks in advance.


Differential oscillator operation details

Started by Anonymous in sci.electronics.design3 years ago 21 replies

Could some electronics guru here please point me to good reference material on operation of differential oscillators ? Thanks in advance.

Could some electronics guru here please point me to good reference material on operation of differential oscillators ? Thanks in advance.


Universal tester, puzzled

Started by Anonymous in sci.electronics.design6 years ago 4 replies

This place again... http://www.eleccircuit.com/universal-tester-circuit-with-vcovoltage-controlled-oscillator/ I don't see how its supposed to...

This place again... http://www.eleccircuit.com/universal-tester-circuit-with-vcovoltage-controlled-oscillator/ I don't see how its supposed to work at all. Do you? NT


Fun with a variac

Started by John Fields in sci.electronics.design8 years ago 13 replies

From an earlier thread about the frequency response of variacs, I realized that a variac could be used as a variable inductor. As such, it...

From an earlier thread about the frequency response of variacs, I realized that a variac could be used as a variable inductor. As such, it could be used to vary the frequency of an oscillator. I kluged this together with stuff I've got around the shop just to see what tuning range I could get. (View with a fixed-pitch font) . +--------------------------------+ . | POWER AM...


Royer oscillator - phasing dots

Started by John S in sci.electronics.design1 year ago 19 replies

https://en.wikipedia.org/wiki/File:Royer_oscillator.gif I think the transformer phasing dots are wrong. Or, am I wrong?

https://en.wikipedia.org/wiki/File:Royer_oscillator.gif I think the transformer phasing dots are wrong. Or, am I wrong?


Could someone please help me understand this ?

Started by Anonymous in sci.electronics.design3 years ago 14 replies

Could some electronics guru here please help me undestand the following. I created the SPICE simulation for a common collector Colpitts...

Could some electronics guru here please help me undestand the following. I created the SPICE simulation for a common collector Colpitts oscillator. The target oscillation frequency is 500.0 MHz, and I am using the HFA3134 RF/microwave NPN transistor, with a Ft of 8 GHz. When the raw transient analysis data is plotted and the resolution adjusted to clearly see individual oscillations, ...


Extract Free Elections From Earth

Started by Kevin Foster in sci.electronics.design5 years ago 62 replies

This researcher has a number of videos in which he appears to draw current from the Earth to supplement an RF oscillator that lights...

This researcher has a number of videos in which he appears to draw current from the Earth to supplement an RF oscillator that lights LED's https://www.youtube.com/watch?v=GufTw6ECoz4 More light with the same current. Any idea what is happening here? Kevin Foster


are all the function generators gone?

Started by John Larkin in sci.electronics.design9 years ago 65 replies

I'm being asked to make some replacement FSK modems for a system I designed about 30 years ago... not much money to be made, really just a...

I'm being asked to make some replacement FSK modems for a system I designed about 30 years ago... not much money to be made, really just a charity job. I originally used the XR2206 as the transmit oscillator, and they are gone. Well, Mouser has one piece for $83. MAX038 is gone, too. Jameco has some 2206 DIPs, which I could scoop up, I guess. Anybody know of a classic analog sinewave gen...


What is this circuit (photo)

Started by Mark Olsen in sci.electronics.design10 years ago 9 replies

Can anyone figure out what this circuit is? There appears to be an LM7812 next to the power switch, and a TO-92 with two switchable RC...

Can anyone figure out what this circuit is? There appears to be an LM7812 next to the power switch, and a TO-92 with two switchable RC networks. http://www.4shared.com/photo/TuR2nDBb/Circuit.html Looks like an oscillator to me, but what type would it be? And what is the rectangular blue part on the lower right side? Mark Olsen


RF in SOCs?

Started by Sonnich Jensen in sci.electronics.design6 years ago 21 replies

Hi guys I havent working with RF for ages, but am using it now. I know about "classic" radios, with coils for filters and OSCs. Now, with SOC...

Hi guys I havent working with RF for ages, but am using it now. I know about "classic" radios, with coils for filters and OSCs. Now, with SOC (system on chip) I dont need to know about it, but I still wonder - I can make an oscillator or PLL, not problem, but say the IF and filters on chip? What replaces the coil-filter in an SOC?


Very precise xtal oscillator?

Started by Anonymous in sci.electronics.design8 years ago 35 replies

Someone has no doubt done this, but I am interested in measuring very small changes in a xtal when it accumulates a surface material. I used...

Someone has no doubt done this, but I am interested in measuring very small changes in a xtal when it accumulates a surface material. I used simple versions in a vacuum chamber for thin film deposition, and they could tell a few Angstroms. But interested in a more sensitive change - say 100-1000X. A BFO? Curious about any thoughts. thanks in advance. JB


'Deadman Oscillator'

Started by Anonymous in sci.electronics.design6 years ago 4 replies

I had a recent need to reset and retry something until it succeeded, but only after a certain delay. My solution-- I vetted several more...

I had a recent need to reset and retry something until it succeeded, but only after a certain delay. My solution-- I vetted several more complex topologies before settling on this-- along the lines of a watchdog timer, but with the ability to retry ad infinitum, this circuit is normally held off by Q1's conduction. A fault condition cuts Q1 off. C1 then charges for a start-up delay time...