Sinus 1watt PLL

[sinus trouble]

The "Sinus PLL" is not perfect? But functions the way it was intended!

please, the term evolution, redesign.. something.. stings my eyes, when I see it I have nightmares. total repulsion. to be GOOD, it must also be beautiful..
Albert? can be a smaller, smd version be made??? it's like a dinosaur! it sucks terribly.

Rigmo, I respect your opinion!

If you dont like it? Dont build it! Makes no difference to me!

I agree, Some of the new SMT technology is fascinating! However, Whilst Stephen had access to new technology? He chose to keep things simple using components available to everyone!

Feel free to share your superior projects with schematics, gerber files and support!

[Albert H]

Sinus

The reason that Stephen stayed with through-hole, conventional components (and no PICs!) was to allow anyone who could solder reasonably well to build a competent transmitter board, with reliable, consistent results. It also meant that if anything got broken, spares would be easily available anywhere in the world.

[rigmo]

Sinus

The reason that Stephen stayed with through-hole, conventional components (and no PICs!) was to allow anyone who could solder reasonably well to build a competent transmitter board, with reliable, consistent results. It also meant that if anything got broken, spares would be easily available anywhere in the world.

Im sure can be coils much smaller and also hand wound..

[sinus trouble]

Sinus

The reason that Stephen stayed with through-hole, conventional components (and no PICs!) was to allow anyone who could solder reasonably well to build a competent transmitter board, with reliable, consistent results. It also meant that if anything got broken, spares would be easily available anywhere in the world.

Im sure can be coils much smaller and also hand wound..

When you say "Coils can be smaller" What do you mean?

If you decrease the diameter? Number of turns will need to increase!

SMT Components could dramatically reduce size? But as Albert mentioned previously, Smaller coils will result in a lower "Q" Factor!

Stripline coils could be used? Yet they are large too!

[Albert H]

The reasons for the larger air-spaced coils in the NRG oscillator was to provide a high Q, allow the use of fairly thick wire to prevent microphonic issues, and to allow for easy tapping every 2-turns of (effectively) a 12 turn coil, and allowing fractional adjustments in value - both for balancing purposes, and fine tuning range adjustments.

We tried various commercial pre-wound inductors, we tried PCB tracks instead of the coils, and we tried moulded chokes. NONE of the alternatives worked as well as the chain of 2-turn coils.

The final advantage of the coils was that by making them with different numbers of turns, you could make that oscillator cover any frequency from ~30 MHz up to ~ 600 MHz. I made a small run of link transmitters that used Lecher lines in the oscillator and as the collector load and matching coils further along the board. With a sensible choice of transistors, I got around 3 Watts out of the Band IV link rigs, which when fed to a TV Yagi, gave a strong signal (albeit very directional) that could be used over tens of miles!

[fmmpastouni]

Mr Albert H ,can you comment on using different kinds of diodes such as red LED,green LED,zener diode,1n4003 diode for modulation and tuning purposes in a FM VCO?Which one is better?I have read your comments on different topics in the past but i cant find them.

[sinus trouble]

Mr Albert H ,can you comment on using different kinds of diodes such as red LED,green LED,zener diode,1n4003 diode for modulation and tuning purposes in a FM VCO?Which one is better?I have read your comments on different topics in the past but i cant find them.

Rigmo already listed many alternative Varicaps previously!

Whilst most diodes inhibit some sort of capacitive characteristics! I would recommend avoiding general purpose rectifier diodes such as the 1N4001 Etc....

[Albert H]

Sinus is right - most rectifier diodes are a bit too noisy for use in an FM modulator. However, 15V zeners generally show a good range of capacitance when reverse biased. Green LEDs are also pretty good, but paint them black if there's any chance of light getting on to them.

[sinus trouble]

I have never tested such diodes before? But it may be worth keeping an eye on the switching time of the diodes you intend to use? (Shown in datasheet)

No doubt most will be able to cope with frequencies in the Mhz region! But you never know?

[Albert H]

Sinus: You're NOT switching them! You're reverse-biasing them and then using the depletion layer as a capacitor! The size and density of the depletion layer will vary somewhat according to the applied reverse-bias voltage, so as long as you're nowhere near the reverse breakdown voltage of the diode, you're going to get a voltage-variable, small value capacitor.

[sinus trouble]

Sinus: You're NOT switching them! You're reverse-biasing them and then using the depletion layer as a capacitor! The size and density of the depletion layer will vary somewhat according to the applied reverse-bias voltage, so as long as you're nowhere near the reverse breakdown voltage of the diode, you're going to get a voltage-variable, small value capacitor.

Haha! Yes you are right Albert! It is not really necessary!

A kinda false habit of mine!