Message	Date	From	Subject
2715	2009-02-20 14:48:48	Eduardo Alonso	GNAT 1/40
congratulations chris! very nice to see a new 1 transistor transceiver and nice solutions to do this complicated task! > File : /The Gnat/Gnat 40 Rev 0.pdf > Uploaded by : chris3trask <christrask@earthlink.net> > Description : A One-Transistor CW Transceiver * use a 2N2222 is a good idea. cheap and easily available. * BD135-6 is another option, high beta=160 for low xtal current but low guaranteed ft (>50MHz). cheap and easily available. * this receiver works in regenerative or super-regenerative mode? Can you listen the oscillator in RX mode? * if you use a speaker and you speak against it and simultaneously you press the key... can anybody listen your voice in the radio? I think the voice modulates the collector current... 73 from Eduardo
2717	2009-02-20 15:40:59	Chris Trask	Re: GNAT 1/40
> > * use a 2N2222 is a good idea. cheap and easily available. > Yes, they will be around after cockroaches are extinct. > > * BD135-6 is another option, high beta=160 for low xtal current > but low guaranteed ft (>50MHz). cheap and easily available. > I have serious doubts about using that transistor for RF applications. > > * this receiver works in regenerative or super-regenerative mode? > Regenrative. > > Can you listen the oscillator in RX mode? > If the circuit breaks into oscillation while in RX mode, it mutes the audio. > > * if you use a speaker and you speak against it and simultaneously > you press the key... can anybody listen your voice in the radio? > I think the voice modulates the collector current... > Now that's an interesting thought. It would be just like Fessenden's original AM transmitter. You would need a pretty hefty microphone. Chris ,----------------------. High Performance Mixers and / What's all this \ Amplifiers for RF Communications / extinct stuff, anyhow? / \ _______,--------------' Chris Trask / N7ZWY _

>
> * use a 2N2222 is a good idea. cheap and easily available.
>

Yes, they will be around after cockroaches are extinct.

>
> * BD135-6 is another option, high beta=160 for low xtal current
> but low guaranteed ft (>50MHz). cheap and easily available.
>

I have serious doubts about using that transistor for RF applications.

>
> * this receiver works in regenerative or super-regenerative mode?
>

Regenrative.

>
> Can you listen the oscillator in RX mode?
>

If the circuit breaks into oscillation while in RX mode, it mutes the
audio.

>
> * if you use a speaker and you speak against it and simultaneously
> you press the key... can anybody listen your voice in the radio?
> I think the voice modulates the collector current...
>

Now that's an interesting thought. It would be just like Fessenden's
original AM transmitter. You would need a pretty hefty microphone.

Chris

,----------------------. High Performance Mixers and
/ What's all this \ Amplifiers for RF Communications
/ extinct stuff, anyhow? /
\ _______,--------------' Chris Trask / N7ZWY
_