TP600 - TPU PULSER

[z_p_e]

@Earl,

Crystal oscillators are not exempt from frequency jitter at all. In fact there are many schemes designed around dealing soley with this issue.

RC oscillators may exhibit frequency jitter as well, but not likely worse than its crystal counterpart. Crystals excel mainly in stability over temperature mainly due to error reduction through frequency division.

At any rate, the TP600/900 is meant mainly as an experimental tool, and should not be worse in performance than the tube oscillators that SM started off using with his testing.

Darren

[turbo]

well there seems to be a diffrence in the harmonic content, it is written in an verry intresting old book i am currently reading (1966) i will examine it somewhat further.

Marco.

"I am using 6BQ7-A tubes for the input and phase inverter because they are VHF amplifier triodes designed to operate in Color TV at very high frequencies and so you can imagine how crystal clear my high frequencies are in my stereo amplifier."

[z_p_e]

PULSE WIDTH CONTROL QUESTION:

What would you guys prefer for the fine pulse width adjustment:

a) a 6 position rotary for fixed stepping (good for repeatability and matching) OR
b) a potentiometer to vary the PW continuously (good for fine adjustment, but will have to rely on control position for approximate repeatability and matching)

?

In either case, there will be a rotary for selecting the Pulse Width RANGE, similar to the Frequency RANGE control. So, two controls for Pulse Width; one is for RANGE, the other for fine adjustment in that range.

Let me know your thoughts, thanks.

Darren

[turbo]

Darren, ho abou both and a switch between to select either one of them?

then we can also easy measure the value of the variable one so when we find something we can write it down.

it has to be as percise as possible when it comes to tunning.

Marco.

[z_p_e]

Darren, ho abou both and a switch between to select either one of them?

then we can also easy measure the value of the variable one so when we find something we can write it down.

it has to be as percise as possible when it comes to tunning.

Marco.

Marco,

Having both can certainly be done, but I'm not sure how practical that is. Please keep in mind that the pulse width will not be that critical. However the frequencies and matching between them in "sync mode", will be critical. As such, I am surprised no one has asked for a "fine" frequency adjust control yet.

Because the pulse width is not that ciritical, I think it best the control be a continuously-variable one, i.e. a potentiometer. Then simply noting the control's position on the panel will allow you to repeat the setting and roughly match it between generators.

For the most part, the Pulse Width has nothing to do with tuning. That's done by altering the frequency. Once the frequency is set, the pulse width can be adjusted for a minimum effective setting. Once set, the Pulse Width control can be left alone, while the frequency control can be adjusted for further tuning.

Cheers,
Darren