À la nuvistor

[Esteban]

Welll... I must say that in some applications tubes are fairly better still today.
The problem is that semiconductors technology never really solved that issue of stability...

As an example... I made many years ago an oscillator for MD using common fets... I made everything absolutely by the book... considered controlling the current and making feedbacks , but , at the end, I tested the oscillator under various conditions and found that was absolutely instable vs temperature, no matter compensation strategies I tested (many).

I've then redesigned using small tubes , 6.3V powered and got perfect , stable sinus , no matter if I also swing an hairdryer near the osc module...
The MD was rock steady, then I learnt that for some stuff... better using old tubes than newer stuff.

About stability, experience say me that mosfets are good... but tubes are BETTER.

Kind regards,
Max

I'm planning first stage only by nuvistor tube, because the first stage is the most important. Nuvistor is very small, light, but consumption is like a common tube, filament 6 V. For filament I need batteries appart.

Another candidate is 1S5 tube, because this need in filament only 1.4 V.

[Clondike Clad]

but tubes are BETTER.

Welll... I must say that in some applications tubes are fairly better still today.
The problem is that semiconductors technology never really solved that issue of stability...

As an example... I made many years ago an oscillator for MD using common fets... I made everything absolutely by the book... considered controlling the current and making feedbacks , but , at the end, I tested the oscillator under various conditions and found that was absolutely instable vs temperature, no matter compensation strategies I tested (many).

I've then redesigned using small tubes , 6.3V powered and got perfect , stable sinus , no matter if I also swing an hairdryer near the osc module...
The MD was rock steady, then I learnt that for some stuff... better using old tubes than newer stuff.

About stability, experience say me that mosfets are good... but tubes are BETTER.


Kind regards,
Max

Yes that is true,BUT use for lrl it is a joke.
Keep on it Max you are doing a good job on this LRL site.

[Esteban]

Yes that is true,BUT use for lrl it is a joke.
Keep on it Max you are doing a good job on this LRL site.

Why, if the first electronic LRL made here was with tube (1959) and has not comparisson...

[Clondike Clad]

if it works the jokes on ME

Why, if the first electronic LRL made here was with tube (1959) and has not comparisson...

Show the circuit and I will build and test it and POST it
If I can't get it to work I will send it to anyone for what it cost me to build it.
From what you are telling us is that unit is as goood as most unit today or better????? .Show us the unit why not let MAX or me build one and test it?IF the tubes unit work LET ME BUILD IT......SHOW THE CIRCUIT ON THIS FORUM...I'LL BUILD IT TEST IT AND POST IT...LET THE JOKE BE ON ME