04-08-2022, 09:31 PM
Hi.
Obviously I don't know the history of the crystals I have nor if they are fundamental or overtone. There is around 10v p-p on the crystal on sound and 8v on vision,
The ones that are coming are 3rd OT and rated at 1mw, well above what I'm doing. So I'll need to make some further changes I would say so the circuit oscillates slightly above the frequency with the crystal removed. I have managed to get the 1ZH37B to oscillate at 120Mhz but obviously with a different approach to this, as this is as minimalistic as possible.
I have had the modulator running for around 4 hours this evening and have been monitoring any drift. So far there has been a drop of 3hz over that period which I think is pretty dam good, it might even be the frequency counter drifting, will also check tomorrow with different test equipment.
Obviously I don't know the history of the crystals I have nor if they are fundamental or overtone. There is around 10v p-p on the crystal on sound and 8v on vision,
The ones that are coming are 3rd OT and rated at 1mw, well above what I'm doing. So I'll need to make some further changes I would say so the circuit oscillates slightly above the frequency with the crystal removed. I have managed to get the 1ZH37B to oscillate at 120Mhz but obviously with a different approach to this, as this is as minimalistic as possible.
I have had the modulator running for around 4 hours this evening and have been monitoring any drift. So far there has been a drop of 3hz over that period which I think is pretty dam good, it might even be the frequency counter drifting, will also check tomorrow with different test equipment.
