EEVblog #1013 - Mailbag - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: August 07, 2017, 01:30:00 am
content: Monster 45min Mailbag!SPOILERS:The Current Source Channel:https://www.youtube.com/channel/UCw0U6DtO0PHb3l37eKEAdSgAnalog meters + VTVM's + Dave's first multimeter.Laser Cut Parts:http://www.cnc-design.fi/wp/Images Of Silicon Valley:http://amzn.to/2vaKqZkBrady label maker teardownSushiBits M193v2 Arduino PCB2DW233 Voltage Reference Zenerhttps://www.eevblog.com/forum/metrology/ultra-low-noise-reference-2dw232-2dw233-2dw23x/Fitbit Teardowni-Extruder Solder Paste Dispenser:https://www.i-extruder.com/en/University of Bristol UB20M Zero Power Standby chiphttp://www.bristol.ac.uk/engineering/research/em/research/zero-standby-power/Silego Reset IC:http://www.silego.com/applications/reset-ic.html

author: boffin
author_rank: Unknown
timestamp: August 07, 2017, 02:40:02 am
content: Could the jtag issue have anything to do with this? Looks like a solder bridge in the videoAs for the 'corner' multimeter. It has exactly the same style of jacks and writing on the range select switch as an RS - It was Japanese re-branded one, I think the company was something like "Ross" -- meter that was my 1st meter.

author: bjcuizon
author_rank: Frequent Contributor
timestamp: August 07, 2017, 04:53:39 am
content: The connector on your VTVM is aSwitchcraft 2501F Microphone Connector.-Go figure. It is some really old school mic connector. I love how it does not have a pin nor a socket. Its like an ancient version of the APC-7 Connector.https://www.google.co.nz/search?q=Switchcraft+2501F+Microphone+Connector&rlz=1C1RLNS_enNZ746NZ746&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjTtJ61qcTVAhWMnJQKHVVrDv8Q_AUICigB&biw=1029&bih=694#imgrc=_

author: bjcuizon
author_rank: Frequent Contributor
timestamp: August 07, 2017, 05:37:11 am
content: Quote from: wilfred on August 07, 2017, 05:21:31 amYup! Absolutely.hehe.

author: technix
author_rank: Super Contributor
timestamp: August 07, 2017, 10:48:14 am
content: Quote from: boffin on August 07, 2017, 02:40:02 amNo it is not the culprit. And it is not a solder bridge either.

author: coppice
author_rank: Super Contributor
timestamp: August 07, 2017, 01:35:46 pm
content: Quote from: bjcuizon on August 07, 2017, 04:53:39 amQuite a lot of low cost test equipment, especially from Japan, used that connector in the late 60s and early 70s.

author: kalel
author_rank: Frequent Contributor
timestamp: August 07, 2017, 01:38:10 pm
content: Quote from: bjcuizon on August 07, 2017, 05:37:11 amWould make a suitable addition to the channel.

author: coppice
author_rank: Super Contributor
timestamp: August 07, 2017, 01:38:44 pm
content: The multimeter at 41:05 was widely available in the UK in the late 60s/early 70s with two or three different brand names on it. My father had one. It was a great value for money little meter, compact, robust and accurate.

author: M4trix
author_rank: Frequent Contributor
timestamp: August 07, 2017, 10:56:51 pm
content: Looks like the I-EXTRUDER dispenser isn't very happy !

author: bjcuizon
author_rank: Frequent Contributor
timestamp: August 08, 2017, 12:26:25 am
content: Quote from: coppice on August 07, 2017, 01:35:46 pmWhy do they not use standard binding posts since binding posts have been here for a long time..maybe since 1905ish.They also even use that mic connector in early RF gear. I wonder what its frequency capability is... Does anyone know?

author: Cerebus
author_rank: Super Contributor
timestamp: August 08, 2017, 04:28:23 pm
content: Quote from: bjcuizon on August 07, 2017, 04:53:39 amBack in the 70s the band I was playing in then inherited a couple of electret microphones that had those Switchcraft connectors on. They made lousy microphone connectors and I have no reason to believe that they'd make better test equipment connectors. They were forever developing intermittent connections on the centre conductor because of flexing from poor strain relief.

author: coppice
author_rank: Super Contributor
timestamp: August 08, 2017, 05:19:10 pm
content: Quote from: Cerebus on August 08, 2017, 04:28:23 pmI had an audio generator and an RF generator in the 70s with those connectors for the outputs. They look crude, but they never gave me any problems. The instruments were from a small Japanese maker which was popular in the UK in the 70s (sold by Henry's Radio, GW Smith, and others), but I've forgotten their name.

author: Cerebus
author_rank: Super Contributor
timestamp: August 08, 2017, 05:28:21 pm
content: Quote from: coppice on August 08, 2017, 05:19:10 pmAltai ?

author: Brumby
author_rank: Unknown
timestamp: August 08, 2017, 05:33:31 pm
content: Microphones tend to have more cable movement with their use than test equipment - both in flexing cycles and intensity .... and also a lot less care.It's like comparing the state of a cake after having been sent via the Post with one you carried yourself.

author: Cerebus
author_rank: Super Contributor
timestamp: August 08, 2017, 06:52:37 pm
content: Quote from: Brumby on August 08, 2017, 05:33:31 pmThat simile only holds if the cake is advertised as "postal cake", remember these were sold as "microphone connectors".

author: Brumby
author_rank: Unknown
timestamp: August 09, 2017, 03:33:00 am
content: Fair comment ... but then, from my observation, the dynamic loads those connectors have been subject to have increased somewhat over the years since they were first introduced as such.Theywerecreated in the earlier developing period of electronics where equipment was generally treated with more care.

author: jh15
author_rank: Frequent Contributor
timestamp: August 09, 2017, 05:48:57 am
content: Fully shielded unbalanced coax vs banana rf exposed wires.

author: Len
author_rank: Frequent Contributor
timestamp: August 17, 2017, 12:22:36 am
content: In case anyone needs it...