Search found 11 matches

by landwn
Thu Jun 02, 2022 6:51 pm
Forum: General Tube Audio Based Discussion
Topic: Why is there an RF oscillator in film optical sound amplifiers?
Replies: 2
Views: 384

Re: Why is there an RF oscillator in film optical sound amplifiers?

I think that the RF oscillator strobed the light at a very high frequency. As the film passed by the slit, the photocell sensed the light based off the soundtrack part on the edge of the film and created an electrical signal based off of that. That signal would be very small and would have to go thr...
by landwn
Thu Jun 02, 2022 6:35 pm
Forum: General Tube Audio Based Discussion
Topic: Radio and TV tubes
Replies: 1
Views: 121

Re: Radio and TV tubes

Good to know. Thanks!
by landwn
Tue Nov 23, 2021 5:41 pm
Forum: Audio Bench & Dummy Load Setup, Test Equipment, Etc.
Topic: HP 3325A Modulation Question
Replies: 0
Views: 670

HP 3325A Modulation Question

I have a question about FM Modulation with an HP 3325A Synthesizer/Function Generator. This generator can do AM and PM modulation. If I understand correctly, I can achieve FM Modulation with the use of an external module like the HP 86632B. Does anyone have experience/knowledge in doing this? If so,...
by landwn
Sat Mar 06, 2021 3:27 pm
Forum: Future Video Ideas
Topic: Virtual Show & Tell
Replies: 16
Views: 3819

Re: Virtual Show & Tell

I'm in. This sounds great!!!
by landwn
Fri Feb 26, 2021 1:56 pm
Forum: Suggestions and Bug Reports
Topic: External URL Hyperlinks
Replies: 4
Views: 1461

External URL Hyperlinks

Kasey, I know that each individual can choose how their browser functions when clicking on a hyperlink, but I think there is something that can be done in the forum settings that will force a new tab for opening hyperlinks. If this is possible in the settings of this forum, can it be applied. There ...
by landwn
Thu Feb 25, 2021 10:06 pm
Forum: Audio Bench & Dummy Load Setup, Test Equipment, Etc.
Topic: Isolation Transformer/oscilliscope/DUT safety
Replies: 12
Views: 2865

Re: Isolation Transformer/oscilliscope/DUT safety

So what makes an isolation transformer safer than a "cheater" plug with the ground tag not hooked up? Can we do this as a student exercise because it is very easy to figure out. Draw the circuit for the simple test set up with the DUT on the cheater plug and the oscilloscope. Accidentally...
by landwn
Thu Feb 25, 2021 10:03 pm
Forum: Audio Bench & Dummy Load Setup, Test Equipment, Etc.
Topic: Isolation Transformer/oscilliscope/DUT safety
Replies: 12
Views: 2865

Re: Isolation Transformer/oscilliscope/DUT safety

Also, to add to the conversation, technically speaking, an isolation transformer refers to a transformer that has no physical connection between primary and secondary conductors, as opposed to an autotransformer (Variac) in which there is physical contact between H and X. The term isolation does not...
by landwn
Thu Feb 25, 2021 9:12 pm
Forum: Future Video Ideas
Topic: a video series explaining basic tube circuits
Replies: 3
Views: 1169

Re: a video series explaining basic tube circuits

Cyborg50, Mark has a complete playlist on what you are after on his channel. This will get you there: https://www.youtube.com/playlist?list=P ... pZnSkPpSjL
by landwn
Thu Feb 25, 2021 9:00 pm
Forum: General Tube Audio Based Discussion
Topic: Magnavox 175 Questions
Replies: 3
Views: 1041

Re: Magnavox 175 Questions

Yes, what Tom_S mentioned should always be a consideration. Changing amp design for frequency cutoffs in the early stages, may have no affect what so ever given the entirety of the system. Not only do you have to consider the OT, but also the speakers.