Steve Anderson wrote:If I had got 10-100V peak-to-peak out of that I would have thought, "I guess that's about right." But just 1.5V or so - I'm sure there's something not quite right...is the frequency anywhere near what you're expecting?
Having no experience with this arrangement I'm not much help...
Steve A.
Me too Steve learning as i go tell you what i am more happy with the Russian Phantastron time base oscillators than this larger one i feel it drifts more ,the small tubes its really stable may be i picked the wrong tubes for the circuit but i think the larger tubes do give a better waveform ramp as in shape ,getting the frequencies for sure free running a little drifting might be a little voltage frequency sensitive ..old 555 timer is like that .
Perhaps a dual pentode and triode might be a better idea every thing nice and close /at the moment 2 pentodes and a dual triode doing the job .
Yes if you are seeing what i am with such a small waveform i think the problem is the 100k resistor for the size control i will redo the test other side of it .
When i built the circuit again with the little Russian tube i left the 100k resistor out i am thinking its reducing the the waveform only way to make sure redo the experiment at the cathode of the triode pin 8 .
I was thinking before i started this the valve time base might just about drive a deflection plate ...always a reason so i will look when i have time at what really is coming out of those tubes .
Always of help Steve always good to see what you think about this stuff .
When i am off work i will do all this again later in the week and if any thing should give better results this time how much find out ; )