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[phantompowers]

On the Casper electronics site, they say to get the pitch bend on the SA series, you have to remove the timing crystal 'cos it has 3 legs. On the SA-2 the crystal has 2 legs, so can I get the pitch bend by soldering a pot across the 2 legs?
Also how can I get an LED to light up when I switch the power on? I can only seem to get it to light up as soon as the battery is connected whether it is switched on or not.
Can anyone help me out?
All the best

[LoFi-Ninja]

No you can't just replace the crystal clock with a pot.. You can try making an variable oscillator in the same area frequency wise. Or you can change the crystal with another one like you could put 10 different crystals on a rotary switch...

About the LED.. Use a multimeter to find a power source that switches of with the SA-2...

[phantompowers]

Thanks for the reply.
I didn't mean replace the crystal with a pot, I was thinking of soldering a pot to the crystal. Would this work?

[Gordonjcp]

No, it's not as simple as that.  The crystal resonates at a particular frequency, and the whole reason for using it is that this frequency doesn't really change much.  About the only thing that *does* affect the crystal frequency once it's cut is temperature, which is why very stable oscillators use crystal ovens to keep them at a steady temperature.

I'm writing up an article about replacing crystal oscillators with a VFO for converting crystal channelised radios to variable frequency operation, and I'll mention it here when I finally get around to finishing and posting it ;-)

[phantompowers]

Oh well, thanks for your reply anyway.

[ne7]

gordon that article sounds ace btw

[computer at sea]

that article

Suffice it to say, I'm very excited about this.

[hoso]

i was goofing around with the precision oscillator kit from get lofi on my sa-2 but i think i got something wrong and wrecked the crystal (or something). it fell off the board and i tried soldering it back but still no sound from the thingy. i was thinking i might replace the crystal but what crystal can i get that will work? on the sa-2 the crystal has two legs (as opposed to the other sa models which, to my understanding, has three)

tips?

[hoso]

or should i just mount the get lofi kit on there and forget about the old crystal?

[Circuitbenders]

The crystal case should say the value on it somewhere. Just replace it with a 2 legged one of the same value if you want it to work like normal.

[hoso]

I was hoping it would be that easy! 22 Mhz is what I've heard- Thanks!