All I found is the AVO 8 MKII user manual with schematic and a document claiming to be the AVO 8 service manual, its a collection of pages in typewriter font describing servicing proceedures - no illustrations.
If you want them name a binaries I can upload to.
Have you tried BAMA? - I haven't been there since they changed their website to stop people like me leeching the whole lot - they've undoubtedly added new stuff since then.
A friend of mine has access to Model 8 I, II, III, V, VI, and VII , but no IV. Curious ... Interestingly, I have now found my book, which I was absolutely certain was issued to me with the meter, and it's for a Mk III , which is entirely different. Hmmm ...
I just went and looked at a BAMA mirror site, and lo ! I have found a file that says it's for the Mk IV. I've downloaded it, but now need to find some software to open it. It says that it is .DJVU format ??
Arfa
Yep. Been to all those places Ian. Thanks anyway
Arfa
Thanks Geo. The Mk 3 is quite different from the 4. I guess that the high price on eBay is commanded by the fact that it seems to be a lot rarer than I thought it was ...
Arfa
Perhaps like Fluke 75 actually specified by name and model in a particular statutary regulation . So if you use anything other than a Fluke 75 it may be an illegal act
Result ! It's fixed ! Looking at all the schematics for the other marks, they all seemed to use a fairly straightforward AC voltage measuring scheme, employing two diodes in bridge with two resistors, for the rectification. In view of the fact that I'd twatted it with a high pulse voltage, I figured that the most likely bet was those diodes. When I found them, they were white glass ones type HG5808, so a fairly bog-standard germanium type. Casting around in the parts drawers, I found a packet of brand new OA91s, so I bunged a couple in, and voila ! - my good old AVO is now reading the right thing again on AC volts
Arfa
The site has links to viewers: see eg
--
Robin
PM may be sent to rbw0{at}hotmail{dot}com
...As the actress said the the bishop, stirring her tea...
In message , Arfa Daily writes
Ah! The Mk 4 is an AVO Multiminor - not an Avo 8. Sorry!
-- Ian
Lizardtech DJVU is a PITA but it produces small files - the main problems are lack of scrolling and you can't set it to restore last viewed page next time you open it.
What I do is open the DJVU with the IE pluggin and hit print with Cutepdf installed (creates a virtual printer which is actually a PDF file), you have to jump to the last page in the DJVU and when the settings box opens reset the from box to 1.
I got used to the LCD after using one for 25 years but it took awhile after using the EICO and a Simpson. The Beckman 310 was the first LCD I owned. I found a benchtop Beckman with LED's back in the 90's I used for several years before it failed beyond repair. Now using my faithful Fluke
-- Live Fast Die Young, Leave A Pretty Corpse
I got me a viewer (I actually have Irfan as well, but didn't realise it did these djvu's) and yes, you are quite right, it is the wrong one, even though it appears to be listed as one of the 8's. Anyways, meter is now fixed - see my later post ! :-)
Arfa
Indeed it is. I have a hand portable DMM that is now the main workshop workhorse, and I am very easy with it. I also have a bench true RMS 6 digit job that is used fairly rarely. The AVO still gets used where I feel it is the appropriate instrument for the job. I tend to be happier using it around tube circuitry for measuring volts, and I prefer its ohms ranges for measuring semiconductor junctions, even though the DMM has a diode test facility
Arfa
It's what you are used to. I started out with an AVO 7 I think it was 500 Ohms per Volt. It certainly had an effect on circuits even in the days before CMOS.
I could turn on transistors and generally interact with circuits using it. Although a tool no doubt aimed at Electrical Engineers it proved a useful diagnostic instrument in an electronics environment.
Oddly enough the AVO eight was potentially more accurate than todays digital afferings. At 20 K to the Volt, The AVO took half the current of the modern DMM.
It was a dashed big needle to shift too.
My gripe with the AVO was that although it was a robust instrument, you could buy around fifteen less robust meters for the same price. Similar accuracy, smaller scale though and at a major price reduction. Plus of course the fact that you could buy batteries to keep the Ohm fires burning at your local newsagent. I seem to recollect tht The AVO needed some kind of battery / inverter replacement when Ever Ready stopped producing their very expensive box of volts.
Incidentally the final AVOs were not robust. They weighed about as much as two of the £12-00 Tandy meters that I used to use at that time.
That was prety light! I zapped a new AVO with one jab at a line output valve topcap. Around 800 V p-p at 15 khz.
I still operate using the same philosophy today. I can pay a hundred or so for a Fluke, or throw £20-00 across the counter at Maplin. Both meters do the same at an acceptable accuracy and both share the same fate when I forget to go from mA to volts when measuring across phases. Both meters also tend to go green & gungy when exposed to liquids. At least I do not feel too bad with a defunct £20-00 Tandy
HN
You too, eh? But they are indeed tough beasts; apart from a shaky ohms-adjust pot it's still working 25 years later.
Doubtful if you could do that with a modern DVM and get away with it.
--
Windmill, Use t m i l l
TiltNot@Nonetel.com @ O n e t e l
. c o m
In article , Windmill writes
The one I measured the mains with was a mid-range ISO-Tech something or other. It blew the internal fuse and worked OK after replacement. But doubt many of the five quid cheapies would survive.
--
(\__/)
(='.'=)
(")_(")
In message , Arfa Daily writes
You can get your own DJVU maker (+viewer) here (and several other interesting things):
-- Ian
Can't remember the exact reason why I stopped using Irfanview for DJVU and went back to the original publishers browser pluggin but the most recent download of DJVU certainly works much better than earlier versions.
Had that problem with my Taylor meter - I wound a blocking oscillator coil on a small toroid and simply shunted the output with a 30V zener, its connected via a pushbutton to the 1.5V low Ohms battery.
My first ever DMM was fished out of the bin where I worked at the time, Ohms & ACV didn't work.
When I opened it there was an OP-AMP in the middle of the PCB - it was sort of easiest to try replacing that and it actually fixed the fault!
The employer very kindly loaned me a recently calibrated instrument and an assortment of adjustable PSUs and resistance decade boxes so I could make the neccessary adjustments to the presets next to the OP-AMP.
I still have it but its been relegated to the shed for occasional automotive work.
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