Author Topic: EEVblog #693 - AVO Transistor Analyser Teardown  (Read 17220 times)

0 Members and 1 Guest are viewing this topic.

Offline EEVblog

  • Administrator
  • *****
  • Posts: 32015
  • Country: au
    • EEVblog
EEVblog #693 - AVO Transistor Analyser Teardown
« on: December 17, 2014, 03:11:57 am »
Dave tears down a 1962 vintage AVO Transistor Analyser.

The auction score video:

 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 15429
  • Country: za
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #1 on: December 17, 2014, 04:24:12 am »
I have the baby brother of that one, it fits in the box in the middle.
 

Offline ratdude747

  • Regular Contributor
  • *
  • Posts: 95
  • Country: us
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #2 on: December 17, 2014, 06:50:03 am »
A note: The two connectors to the battery board ARE latched... if you look, there are two barrel spacers bolted to the inside of the compartment that hold the plug in the socket.
 

Offline Lightages

  • Supporter
  • ****
  • Posts: 4302
  • Country: ca
  • Canadian po
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #3 on: December 17, 2014, 07:05:00 am »
My first thought when seeing those flatish devices marked 1R is that they were diodes. I would never have thought them to be capacitors. Are you sure Dave?
 

Offline digital

  • Contributor
  • Posts: 47
  • Country: au
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #4 on: December 17, 2014, 08:22:02 am »
Dave please replace that condenser and do a video of the tester working I am sure a lot of others would enjoy it.Regards
 

Offline G7PSK

  • Super Contributor
  • ***
  • Posts: 3705
  • Country: gb
  • It is hot until proved not.
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #5 on: December 17, 2014, 09:05:15 am »
Hi Dave, To make AA batteries fit you need a stack of coins to fit under the spring and on top of the cell.
I have a whole load of 1950's to early 1970's transistors I can send you to test all brand new and unused.
Your unit could well have been unused as the military have the  habit of storing equipment just in case they have a war and then after forty years or so realise that it is out of date, I have had a few bits of kit unused ex military.
 

Offline German_EE

  • Super Contributor
  • ***
  • Posts: 2400
  • Country: de
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #6 on: December 17, 2014, 09:29:52 am »
Dave, I am almost certain that your analyser is ex-military. The secret is the brass plate which shows a small arrow pointing upwards, this was the symbol for the War Department in the UK (now called the Ministry of Defence). Now that we know you are dealing with a military device it explains the build quality including the laced wiring, the chunky switches and the rubber seals.

I was Sagan's age when this unit was manufactured :-+
Should you find yourself in a chronically leaking boat, energy devoted to changing vessels is likely to be more productive than energy devoted to patching leaks.

Warren Buffett
 

Offline jipihorn

  • Contributor
  • Posts: 19
  • Country: fr
    • jipihorn blog
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #7 on: December 17, 2014, 10:08:21 am »
"Love a good set of balls"

Brilliant.

J.
 

Offline nathanpc

  • Supporter
  • ****
  • Posts: 138
  • Country: br
    • Innove Workshop
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #8 on: December 17, 2014, 10:45:44 am »
I would love to see a video of you replacing those old capacitors condensers and playing around with it analyzing some transistors.
 

Offline fcb

  • Super Contributor
  • ***
  • Posts: 1643
  • Country: gb
  • Test instrument designer/maker G1YWC.
    • Electron Plus
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #9 on: December 17, 2014, 11:33:21 am »
I think you'll find all AVO stuff of that vintage is equally well built.

What is slightly puzzling (mainly because I don't know the history of the UK<>ADF agreements) is why it has the UK MOD plaque on it.
https://electron.plus Power Analysers, VI Signature Testers, Voltage References.
 

Offline JackOfVA

  • Supporter
  • ****
  • Posts: 350
  • Country: us
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #10 on: December 17, 2014, 12:25:54 pm »
Battery holders appear to be based on 7 or 9 pin vacuum tube sockets and shields.

Yes, please see if you can make it work - would make a great 2nd part video.

 

Offline R_Gtx

  • Regular Contributor
  • *
  • Posts: 52
  • Country: gb
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #11 on: December 17, 2014, 01:08:39 pm »
I hope Dave doesn't just swap the leaky dustbins with modern replacements, but correctly, as with all vintage equipment, re-stuffs the original cans.
 

Offline c4757p

  • Super Contributor
  • ***
  • Posts: 7805
  • Country: us
  • adieu
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #12 on: December 17, 2014, 01:20:33 pm »
Ew, god, restuff the cans? I hate it when people do that. This is a tool, and a beautiful piece of engineering, not some wanky painting or something - its beauty comes from the practical, functional design, not the specific shape and size of the capacitors... Hiding nice, modern parts inside crusty old ones seems to me a bit of an insult to the spirit of the engineering work that went into building this in the first place. Do you think, given a choice between a modern capacitor from 2014 and one of the caps that were available in the 1960s, the original engineers would have chosen the latter?
No longer active here - try the IRC channel if you just can't be without me :)
 

Offline Macbeth

  • Super Contributor
  • ***
  • Posts: 2562
  • Country: gb
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #13 on: December 17, 2014, 01:25:36 pm »
My first thought when seeing those flatish devices marked 1R is that they were diodes. I would never have thought them to be capacitors. Are you sure Dave?
I instantly thought this too...
 

Offline Refrigerator

  • Frequent Contributor
  • **
  • Posts: 969
  • Country: lt
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #14 on: December 17, 2014, 01:32:19 pm »
Imo a C cell battery would fit perfecly in those battery cans .  :)
I have a blog at http://brimmingideas.blogspot.com/ . Now less empty than ever before !
 

Offline c4757p

  • Super Contributor
  • ***
  • Posts: 7805
  • Country: us
  • adieu
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #15 on: December 17, 2014, 01:33:51 pm »
Imo a C cell battery would fit perfecly in those battery cans .  :)

Do you think so? They looked just a bit too small to me - but then again, I don't handle C cells much.

My first thought when seeing those flatish devices marked 1R is that they were diodes. I would never have thought them to be capacitors. Are you sure Dave?
I instantly thought this too...

Yup, those look like diodes to me.
No longer active here - try the IRC channel if you just can't be without me :)
 

Offline Macbeth

  • Super Contributor
  • ***
  • Posts: 2562
  • Country: gb
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #16 on: December 17, 2014, 01:34:13 pm »
Dave, I am almost certain that your analyser is ex-military. The secret is the brass plate which shows a small arrow pointing upwards, this was the symbol for the War Department in the UK (now called the Ministry of Defence). Now that we know you are dealing with a military device it explains the build quality including the laced wiring, the chunky switches and the rubber seals.

I was Sagan's age when this unit was manufactured :-+
Definitely Ministry of Defence. I also wonder about that "MOD" sticker Dave thinks is for recording modifications. I think it is for some other M.O.D. purposes myself.

The arrow you speak of is also printed on the clockface of UK military watches, ration packs, belt buckles, etc, etc.

I have to hand it to AVO, they made fantastic old school meters like the AVO-8 in their bakelite cases with hand wound resistors, and hand painted and calibrated dials with parallax mirror. I would say a whole magnitude in quality above an old Simpson.
 

Offline German_EE

  • Super Contributor
  • ***
  • Posts: 2400
  • Country: de
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #17 on: December 17, 2014, 02:37:45 pm »
Wikipedia says that the War Department / War Office became the Ministry of Defence in 1964, after this unit was manufactured. 'MOD' on the inside plate is therefore to mark MODifications 1-25.
Should you find yourself in a chronically leaking boat, energy devoted to changing vessels is likely to be more productive than energy devoted to patching leaks.

Warren Buffett
 

Offline Andy Watson

  • Super Contributor
  • ***
  • Posts: 1758
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #18 on: December 17, 2014, 02:57:59 pm »
My first thought when seeing those flatish devices marked 1R is that they were diodes. I would never have thought them to be capacitors. Are you sure Dave?
Agreed. They're IR (International Rectifier) 2E1 diodes.
 

Offline RobertoLG

  • Frequent Contributor
  • **
  • Posts: 361
  • Country: br
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #19 on: December 17, 2014, 03:36:39 pm »
Dave here are some battery adapters, maybe you are interested for future use, dunno anyways here is the link

http://www.amazon.com/C-sized-Adapter-Shells-AA-Battery/dp/B000855034
 

Offline w2aew

  • Super Contributor
  • ***
  • Posts: 1752
  • Country: us
  • I usTa cuDnt speL enjinere, noW I aR wuN
    • My YouTube Channel
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #20 on: December 17, 2014, 04:06:09 pm »
Gee - I hope I look as good as that thing does when I'm that old.  Oh wait, I *am* that old!  I was born the same year that it was born...
YouTube channel: https://www.youtube.com/w2aew
FAE for Tektronix
Technical Coordinator for the ARRL Northern NJ Section
 

Offline Dave Turner

  • Frequent Contributor
  • **
  • Posts: 439
  • Country: gb
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #21 on: December 17, 2014, 04:59:35 pm »
According to http://www.vintage-radio.net/forum/showthread.php?t=78716
the 1289 4.5v cycle battery would yield 3 U10 sized cells. I've not tried it myself but may be worth checking out.
 

Offline Electronics-Repairman

  • Contributor
  • Posts: 42
  • Country: 00
  • More people talk about Electronics than do it
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #22 on: December 17, 2014, 05:32:06 pm »
Yes Dave please fix it,I'd love to see it working. :-+
If it's highly recommended, then  I'm not interested.
 

Offline PA4TIM

  • Super Contributor
  • ***
  • Posts: 1125
  • Country: nl
  • instruments are like rabbits, they multiply fast
    • PA4TIMs shelter for orphan measurement stuff
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #23 on: December 17, 2014, 07:05:47 pm »
CT models are military models/versions. I have a CT38, a huge avo VTVM , CV is also a militairy thing, many tubes have a CV number. I have seen those MOD plates on many english militairy stuff. Like on Murphy's (ao on a 1949 version) and Racals. I do not think it stands for  modification.
www.pa4tim.nl my collection measurement gear and experiments Also lots of info about network analyse
www.schneiderelectronicsrepair.nl  repair of test and calibration equipment
https://www.youtube.com/user/pa4tim my youtube channel
 

Offline fcb

  • Super Contributor
  • ***
  • Posts: 1643
  • Country: gb
  • Test instrument designer/maker G1YWC.
    • Electron Plus
Re: EEVblog #693 - AVO Transistor Analyser Teardown
« Reply #24 on: December 17, 2014, 07:45:53 pm »
Those MOD plates do stand for MODification - they are (or were) very common on gear here in the UK, you often see them with numbers punched out/scratched or ticked indicating which mods have been performed.  I've seen brand new gear delivered with a few of these punched out before.
https://electron.plus Power Analysers, VI Signature Testers, Voltage References.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf