Bun's Lab – Telegram
Bun's Lab
@BunsLab
147 subscribers
1.81K photos
102 videos
63 files
49 links
Electronics projects, vintæg computing, programming and repairs. A minimalist blog of sorts.
@BunsGarden @BunsNook
Download Telegram
About
Blog
Apps
Platform
Join
Bun's Lab
147 subscribers
Bun's Lab
Fluke 8050A_sch.pdf
231.4 KB
Fluke 8050A_replaceable.pdf
290.6 KB
Fluke 8050A_recharg-batt-option.pdf
381.7 KB
Fluke 8050A_maintenance.pdf
429.7 KB
FLUKE 8050A Instruction.pdf
5.1 MB
161 views
Bun's Lab
Unrelated.

Really cool bio channel, give it a watch
https://www.youtube.com/watch?v=eSMnQPF15tA
YouTube
Are Prions Truly Impossible to Destroy?
Prions are some of the most terrifying biological agents out there. Here is a video detailing (almost) everything I could find about these special proteins.

Business Inquiries: ybtspod@gmail.com

Become a member! https://www.youtube.com/channel/UCom09c…
169 views
Bun's Lab
Next on the bench: a PM 5133 function generator made by Philips
❤1
129 views
Bun's Lab
This media is not supported in your browser
VIEW IN TELEGRAM
It's pretty dead
131 views
Bun's Lab
129 views
Bun's Lab
The main oscillator is not running. Shown here is the range selection and integration capacitors
147 views
Bun's Lab
philips--pm-5133--service-user--ID8639.pdf
27.2 MB
Service manual
133 views
Bun's Lab
Theory of operation and a simplified schematic of the main oscillator
136 views
Bun's Lab
p70.png
10.9 MB
Relevant schematic parts in full
p67.png
16.5 MB
148 views
Bun's Lab
The transistor pair 423 of the comparator is realized as a CA3183E transistor array in a PDIP package.
152 viewsedited  
Bun's Lab
Cutting the gate of the BF245 JFET out of circuit and feeding the blue signal into it. Red is the final output, I can control the amplitude and waveform just fine. Green and yellow are the bases of the two comparator transistors 423.
149 views
Bun's Lab
Blue is still the input to the gate of the JFET, red the final output. Green the base of the second transistor of the comparator pair, yellow the signal at the junction of the emitter of 365 and collector of 366. According to the schematic the amplitude there should be 5V. Blue cuts out for anything below 5.2V however. Curious. No idea if I'm onto something.
157 views
Bun's Lab
Adjusting pots 830 and 837 of the comparator for 50% duty cycle and stable triggering for 5V signal amplitude
158 views
Bun's Lab
Since I know that the green section works, I cut out the burst control by lifting one side of the diode there and checked those four transistors manually
160 viewsedited  
Bun's Lab
One of them is iffy. A BF450
171 views