Products > Test Equipment

Test Equipment Anonymous (TEA) group therapy thread

<< < (21591/24007) > >>

mnementh:

--- Quote from: Neomys Sapiens on November 29, 2021, 03:37:26 am ---
--- Quote from: vk6zgo on November 28, 2021, 02:46:02 pm ---
--- Quote from: VK5RC on November 28, 2021, 09:25:58 am ---Meets quite a few criteria,
Test equipment tick
Nixie tube tick
Ham related tick
It works tick
Happy camper here

Does need sl weird power supply (220v, we have 240v and with all the solar feed in, it often hits 250v)

--- End quote ---

West Oz used to be 250v, & plenty of devices with supposedly lower voltage ratings operated merrily for decades.

As factory has pointed out, the thing has adjustable transformer primary taps.
A "234" volt setting will operate ok on 250v "till the cows come home".

--- End quote ---

Immediately I envisage some content operator in front of his equipment, until a loud 'MOOOO' is heard from the window. In the same moment an evil flash, smoldering sound and thick smoke emanates from the rear of some device!

--- End quote ---


mnem
Still less brain damage than 4 hours of surfing "funny" cat memes... >:D

RolandK:

--- Quote from: tggzzz on November 26, 2021, 10:58:24 am ---The divide-by-10 circuits in the 1965 Tek 184 use only 3 transistors. How do they do that? Having debugged mine, that's a rhetorical question!

--- End quote ---

Just wondered how they did it, because with 3 storage-stages you can encode 2^3. So i looked in the schematic. But they used 2 stages: one devide by 2 and one devide by 5. Both use 3 transistors. Or didn't i see something?

mnementh:

--- Quote from: vk6zgo on November 29, 2021, 12:13:15 am ---
--- Quote from: Vince on November 28, 2021, 05:35:52 pm ---

--- End quote ---

Those funny looking transistor symbols were "the latest & greatest" in the early 1960s, & some early adopters got their fingers burned when they went with them. One such was the Oz electronics mag "Electronics Australia", who adopted them whole-heartedly, only to have to backpedal a while later, when they realised they "went over like a wrought iron hanglider" in industry.

Your frequency counter is only the second time that I saw them used in a commercially produced schematic.The other was when I had to read the schematic of a device produced by "Commonwealth Electronics" for our old aviation regulator, as part of the old "Broadcast Operator's Certificate of Proficiency" practical test.

I think they kept it as "a trap for young players"----but I was an "old player!" 8)
--- End quote ---


Oh, fuck... those symbols are positively demonic! It's like they're trying to deliberately make the elements as ambiguous as possible!   :wtf:

Whoever thought that was a good idea needs to be strung up by 'is nutsack...  :rant:

mnem
Probably the same dingle who made it normal to diagram all the pins on a IC out of order so the traces would look neater... and who gave us autoroute... |O

mnementh:

--- Quote from: capt bullshot on November 29, 2021, 09:28:30 am ---Not exactly fun with TEA here, but I've had some fun building a simple transistor test adapter for the Tek 577:

Nothing to tell your mother about, just using stuff that was readily available in the stash. No PCB layout, just perfboard, no fancy white solder mask with black silkscreen, just a printed piece of paper.

      
--- End quote ---


Oooooh... now that one definitely earns the  UGLY ENGINEERING  seal of approval!  :-DD

Just please... tack those loose corners down... *cringe*    ;)

mnem
 :-/O

SeanB:

--- Quote from: RolandK on November 29, 2021, 01:51:35 pm ---
--- Quote from: tggzzz on November 26, 2021, 10:58:24 am ---The divide-by-10 circuits in the 1965 Tek 184 use only 3 transistors. How do they do that? Having debugged mine, that's a rhetorical question!

--- End quote ---

Just wondered how they did it, because with 3 storage-stages you can encode 2^3. So i looked in the schematic. But they used 2 stages: one devide by 2 and one devide by 5. Both use 3 transistors. Or didn't i see something?

Pulse counting, they select the capacitor and resistor values, so that you need a certain number of pulses, before the transistor starts to conduct, blanking the input for the remainder of the pulses. Needs to have very specific input frequencies, and very narrow bounds on component tolerance as well to get it to work, but you can do a divide by n over a small range, providing your input frequency is constant.

--- End quote ---

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version