Looking for low-frequency PIN diode

Started by Anonymous in sci.electronics.design9 years ago 19 replies

I=92m developing a simple, five-frequency superhetrodyne receiver to operat= e between 2.5 MHz to 20 MHz in which the local oscillator crystals...

I=92m developing a simple, five-frequency superhetrodyne receiver to operat= e between 2.5 MHz to 20 MHz in which the local oscillator crystals and whip= antenna tuning circuits are selected (switched) using diodes. Here=92s the= problem:=20 The whip tuning circuit is comprised of a single variable capacitor with fi= ve fixed-value inductors, each in series with a BA277 "bandswtiching" di...


spec out low power bjt

Started by panfilero in sci.electronics.design9 years ago 17 replies

I'd like to make a low power one shot circuit, I'm planning to use a monost= able oscillator to get my one shot functionality, but I was...

I'd like to make a low power one shot circuit, I'm planning to use a monost= able oscillator to get my one shot functionality, but I was wondering what = NPN transistor specs do I need to look for in order to get the lowest power= circuit out of this? The circuit I'm building is below link: http://pcbheaven.com/scripts/imagepresent.php?filename=3D%2Fwikipages%2Fima= ges%2Ftransistorcircu...


Lighting a LED with a candle flame

Started by Jan Panteltje in sci.electronics.design9 years ago 34 replies

Lighting a LED with a candle flame After reflecting on the circuit 'oscillator running on home made thermocouple', and failing to get a LED...

Lighting a LED with a candle flame After reflecting on the circuit 'oscillator running on home made thermocouple', and failing to get a LED lighting up yesterday, it all fell into places, and I realized that the means to obtain the required 2V DC for the LED WAS ALREADY THERE. For the curious and experimenters, here is the complete diagram: http://panteltje.com/pub/lighting_a_LED_with...


Wavetek 273

Started by Tim Wescott in sci.electronics.design10 years ago 32 replies

Anyone got any mileage, manuals, rumors, etc. of the Wavetek 273 signal generator? A customer is testing a PLL that I designed. The PLL is...

Anyone got any mileage, manuals, rumors, etc. of the Wavetek 273 signal generator? A customer is testing a PLL that I designed. The PLL is designed to go into the far sub-Hz bandwidths, and they're having trouble getting it to lock onto the 15kHz signal from a Wavetek 273. I've got it running off of a crystal oscillator divided down and made into a sine wave, and it's perking along ...


Crystal Controlled Oscillator

Started by Artist in sci.electronics.design3 weeks ago 53 replies

I have been tasked with designing a piezoelectric actuator driver at its resonant frequency. This is to replace an arrangement where the sine...

I have been tasked with designing a piezoelectric actuator driver at its resonant frequency. This is to replace an arrangement where the sine wave source is a function generator chip (the obsolete XR-2206) that must be individually tweaked on a unit, by unit basis, to match the crystal?s resonant frequency. The crystal is used as an actuator to vibrate a mirror used in a laser syste


A 2.4GHz to 1.5 GHz down converter layout, and VCO internals.

Started by Jan Panteltje in sci.electronics.design7 years ago

A 2.4GHz to 1.5 GHz down converter A whole new range of interesting frequencies opens up with this litte converter, here now in box with...

A 2.4GHz to 1.5 GHz down converter A whole new range of interesting frequencies opens up with this litte converter, here now in box with antenna: http://panteltje.com/pub/2.4_GHz_to_1.5_GHz_mixer_in_box_IMG_4661.JPG Modified my rtl_sdr based xpsa spectrum analyzer software to allow for a local oscillator setting: I found a peculiar very strong intermittent signal around 2432271360 H...


3904 (again)

Started by Yzordderrex in sci.electronics.design2 years ago 11 replies

A client came to me with a battery design that isn't meeting lifetime spec. The unit is a small transmitter to track people in hospital type...

A client came to me with a battery design that isn't meeting lifetime spec. The unit is a small transmitter to track people in hospital type environments. The circuit runs off of a 3v battery. There is a 60k resistor from gpio output to the base of common emitter 3904. The collector is tied to one end of ferrite antenna. Other end is tied to 3v. 3904 is used between oscillator and the ferri...


more Dremel fun

Started by John Larkin in sci.electronics.design5 years ago 18 replies

We built a new oscillator prototype, on a 4-layer board, and the temperature coefficient is a lot worse than expected. Heating and cooling...

We built a new oscillator prototype, on a 4-layer board, and the temperature coefficient is a lot worse than expected. Heating and cooling individual parts doesn't make sensible numbers, so we're suspecting the PCB laminate. It's a 4-layer board, FR4, with layer 2 ground. FR4 makes terrible capacitors. I should have removed ground plane under the critical nodes, but it's never too late...


ADCMP561 spice model

Started by John Larkin in sci.electronics.design7 years ago 1 reply

Analog Devices makes some nice PECL comparators, but the data sheets are old and iffy, and there don't seem to be any Spice models. It...

Analog Devices makes some nice PECL comparators, but the data sheets are old and iffy, and there don't seem to be any Spice models. It was raining and snowing and I couldn't go skiing, so I did a behavioral model. I plan to use one of these to make a pretty good 500 MHz oscillator, so I wanted to get it mostly right. Jim's TANH thing is a nice way to make a saturating stage. The open-emit...


Reflex regenerative receiver again

Started by bitrex in sci.electronics.design6 years ago

So I'm buidling this cool little reflex receiver! It's using a 12EC8 triode/pentode, with the triode performing RF/audio gain duties and the...

So I'm buidling this cool little reflex receiver! It's using a 12EC8 triode/pentode, with the triode performing RF/audio gain duties and the pentode used as the regen amp/oscillator/detector. Power is provided by a 4 "C" cell battery pack and boosted to 12 volts by one of those eBay China special switchers, wrapped up in shielding. The B+ looks pretty clean on my scope so I hope int...


GaN fet ring oscillator

Started by Anonymous in sci.electronics.design8 months ago 6 replies

https://www.dropbox.com/sh/4j35ny39w8fo343/AACp_DApeRQRaMLsvh3KMLWFa?dl=0 I think the frequency should settle down to 1/(10*Tpd) but it...

https://www.dropbox.com/sh/4j35ny39w8fo343/AACp_DApeRQRaMLsvh3KMLWFa?dl=0 I think the frequency should settle down to 1/(10*Tpd) but it doesn't. We might do some pcb footprint tests for the tiny EPC fets, and I thought a board with a lot of ring oscillators would be a good way to test for good soldering. The EPC data sheet recommends a tiny solder-mask-defined pad arrangement that th...


pretty good frequency counter

Started by Anonymous in sci.electronics.design2 years ago 27 replies

Anybody have one of...

Anybody have one of these? https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv =0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25 I'll have my new 150 MHz Colpitts LC oscillator test board in a week or so, and I need a modestly good frequency counter for testing. We usually buy some high-end Keysight counter/timer for


Gilbert transconductance cell ( how does it work?)

Started by Bill Bowden in sci.electronics.design7 years ago 17 replies

Anybody know how this thing works? It seems to simulate ok but I'm unclear how 2 frequencies produce a difference frequency.with a gain of 30dB...

Anybody know how this thing works? It seems to simulate ok but I'm unclear how 2 frequencies produce a difference frequency.with a gain of 30dB or more across the LC .The signal input is 640KHz at 1 millivolt and the oscillator frequency is 1095KHz at 500mV for a difference of 455KHz at 50mV. Version 4 SHEET 1 912 680 WIRE -32 -224 -112 -224 WIRE 64 -224 -32 -224 WIRE 304 -224 64 -22...


Power spectrum question -- seek verification

Started by Anonymous in sci.electronics.design3 years ago 7 replies

Could some electronics guru here please verify this ? Suppose that I calculate the power spectrum of an oscillator output. In the time domain...

Could some electronics guru here please verify this ? Suppose that I calculate the power spectrum of an oscillator output. In the time domain the output is a sine wave across a 50 Ohm resistor, with units of Volts. When the Discrete Fourier Transform(DFT) is computed, followed by the power spectrum, what would be units of the vertical axis. The horizontal axis unit is Hz. As the raw DF...


Techniques for creating a 1GHz signal

Started by mook johnson in sci.electronics.design9 years ago 19 replies

Gents, I may have toe venture from my cozy home in the sum 10MHz range to the high frequency RF stuff on the hundreds of MHz to low GHz...

Gents, I may have toe venture from my cozy home in the sum 10MHz range to the high frequency RF stuff on the hundreds of MHz to low GHz range. First order of business is a 1GHz signwave generator. What are the common techniques for generating something that high? DDS? Hartley type oscillator, Crystal with upper harmonic filter to isolate the 1GHz band. I'm thinking this will be ...


Precison sapphire oscillator

Started by Anthony William Sloman in sci.electronics.design6 months ago 16 replies

A recent copy of the IEEE Spectrum included this...

A recent copy of the IEEE Spectrum included this article https://spectrum.ieee.org/for-precision-the-sapphire-clock-outshines-even-the-best-atomic-clocks It isn't as stable as an atomic clock over an extended period but it's short-term accuracy is much better. Each clock period is much closer to being perfectly equal to the last one. And it is an Australian development ... -- Bill


More on GHz shielding and GPS

Started by Jan Panteltje in sci.electronics.design9 years ago 8 replies

Little 157540000Hz (1.5GHz) oscillator, now in real alu box: http://panteltje.com/pub/pseudolite_box_IMG_3751.GIF This RF probe ...

Little 157540000Hz (1.5GHz) oscillator, now in real alu box: http://panteltje.com/pub/pseudolite_box_IMG_3751.GIF This RF probe http://panteltje.com/pub/1.5GHz_RF_probe_IMG_3647.GIF still clearly shows strong RF signals coming out of the extremely small gaps


SPICE simulation -- how to bias a crystal oscillatoir

Started by Anonymous in sci.electronics.design6 years ago 26 replies

Could some electronics/SPICE guru please help ? I have a simple model of a quartz crystal, as used in an oscillator. With my SPICE simulation, I...

Could some electronics/SPICE guru please help ? I have a simple model of a quartz crystal, as used in an oscillator. With my SPICE simulation, I can measure both the parallel and series resonant frequencies of the "pure" crystal. However, when I attach the same crystal to a biasing circuit, and run the simulation, the output is a flat DC offset. The biasing circuit involves two CMOS(1.0u m...


one-IC digital PLL?

Started by frank in sci.electronics.design6 years ago 15 replies

Hi all, I'm looking for a small-real-estate solution to generate a clock (ttl/cmos 5V) from a given quartz oscillator. The output clock I need...

Hi all, I'm looking for a small-real-estate solution to generate a clock (ttl/cmos 5V) from a given quartz oscillator. The output clock I need is 4/9 or 4/7 ratio of the original input clock. I know I can easily make a VCO/PLL solution, but the real problem is a very small space on the PCB, so I might be able to use a couple of small ICs, but probably not too much else. Input clock is < 2


Peter Baxandall's 1959 Class-D oscillator paper.

Started by Bill Sloman in sci.electronics.design8 years ago 3 replies

This has been available on my web-site for a couple of years. The web-site has moved to Australia and the URL has changed in the...

This has been available on my web-site for a couple of years. The web-site has moved to Australia and the URL has changed in the process. The new URL for the scanned image of the paper is http://sophia-elektronica.com/0344_001_Baxandal.pdf It has been posted with permission from the UK IEE who own the copyright, as noted here http://sophia-elektronica.com/Baxandall_parallel-resonant...