Hello, why i have to wait for 100ms ? ONE HOUR AND HALF, ltspice

Audioguru

Joined Dec 20, 2007
11,249
He is not making the circuit, instead he is simulating it and so was I. I doubt the SIM program knows about stray capacitance.
I do not have a model for a geranium diode so I used a Schottky.
All the FM radios I have seen and made have adjustable cores in the discriminator transformer to adjust the frequency.
 

Thread Starter

michael1978

Joined Jun 29, 2014
309
He is not making the circuit, instead he is simulating it and so was I. I doubt the SIM program knows about stray capacitance.
I do not have a model for a geranium diode so I used a Schottky.
All the FM radios I have seen and made have adjustable cores in the discriminator transformer to adjust the frequency.
Hi Audioguru thanks, i wil like to ask you, is there any problem? to build a circuits? why i hear about parastic capacitor, i need to add extra capacitor or what?
 

Thread Starter

michael1978

Joined Jun 29, 2014
309
hi 1978,
Did you download the @Bordodynov LTS linked version of LTS, it has all the models used in your circuit.
It may have Ge diodes if you search thru it.???
E
i download will a lot of semiconductors, i search i found 10 or 15 ge, because i format the disk i reinstall win 10? and i found somewhere else?
 
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Bordodynov

Joined May 20, 2015
2,869
He is not making the circuit, instead he is simulating it and so was I. I doubt the SIM program knows about stray capacitance.
I do not have a model for a geranium diode so I used a Schottky.
All the FM radios I have seen and made have adjustable cores in the discriminator transformer to adjust the frequency.
On my web page there are models of many germanium diodes of many Schottky diodes.
For demodulation purposes, the BAS70 diode is a good fit. In extreme cases, BAT54.
Spice model 1N5817:
.model 1n5817 d (is = 31.7u rs = .051 n = 1.373 cjo = 190p m = .3 eg = .69 xti = 2 iave = 1 vpk = 20 mfg = onsemi type = schottky)
==> cjo = 190pF it is a barrier capacitance at a voltage of 0 V.
200 pF is a large parasitic capacitance. And all your resonances are much lower than the working frequency.
 

Audioguru

Joined Dec 20, 2007
11,249
56 years ago I made an FM tuner from an Eico kit. It used vacuum tubes. I can't remember if it used a ratio detector or a discriminator and If it was tuned with the inductance or trimmer capacitors.
I remember tuning for a symmetrical "S" curve.

Today, I wonder where Michael will buy a discriminator transformer?
 

Thread Starter

michael1978

Joined Jun 29, 2014
309
56 years ago I made an FM tuner from an Eico kit. It used vacuum tubes. I can't remember if it used a ratio detector or a discriminator and If it was tuned with the inductance or trimmer capacitors.
I remember tuning for a symmetrical "S" curve.

Today, I wonder where Michael will buy a discriminator transformer?
but you see here is maked with transformer and capacitor in ltspice(what is the problem)i gonna make it, that can build of not? i think i to do it with transformer and trimmer can you do it like this?
 
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Thread Starter

michael1978

Joined Jun 29, 2014
309
On my web page there are models of many germanium diodes of many Schottky diodes.
For demodulation purposes, the BAS70 diode is a good fit. In extreme cases, BAT54.
Spice model 1N5817:
.model 1n5817 d (is = 31.7u rs = .051 n = 1.373 cjo = 190p m = .3 eg = .69 xti = 2 iave = 1 vpk = 20 mfg = onsemi type = schottky)
==> cjo = 190pF it is a barrier capacitance at a voltage of 0 V.
200 pF is a large parasitic capacitance. And all your resonances are much lower than the working frequency.
i goona check now, if i have this type, i have that type...…...
Sorry may i ask you? where is link of you website?
 
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Audioguru

Joined Dec 20, 2007
11,249
I think discriminator transformers for an old FM radio circuit are not made anymore, also IF transformers that you need are also not made anymore. Find an old radio and use its parts.
The Elenco AM-FM superheterodyne radio kit has the old transformers you need. You also need a signal generator and oscilloscope to align the transformers.
 

Thread Starter

michael1978

Joined Jun 29, 2014
309
I think discriminator transformers for an old FM radio circuit are not made anymore, also IF transformers that you need are also not made anymore. Find an old radio and use its parts.
The Elenco AM-FM superheterodyne radio kit has the old transformers you need. You also need a signal generator and oscilloscope to align the transformers.
But i learn nothing from that radio, he work perfect like fm and like am, pffffn, but if you want, what you need to make make one fm in this time? have a nice sleep...…..
 
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