There's a blast from the past ! I used to work weekends in a repair shop in the 80's and every now and again the AVO8 would make an appearance, I can remember it had a big satchel like case leather case, and was treated with respect,unlike the digi meters which were thrown everywhere. Nice vid.
one thing that new users often get confused with and think it's faulty: the meter cutout can only be reset when the meter is horizontal (flat on the bench)
I have a great condition one of the model you have in the video and still use it for sudden fluctuating voltage changes like in communications receiver calibration, audio signal level checking and is far better at Ni-Cad/NiMH voltage battery level checks than a DMM. They looks great on the shelf just like the technicians had them back when I was at college in the 80s. It was my dream meter back then so does have some of sentimental value to me. They are built to last a lifetime.
In the US, we had the Simpson 260. Complete with a real Bakelite case. It didn't quite have the range of yours, but it didn't need an odd 15 volt battery either. I think one other reason for D cells - back in the 60's when that was designed, you didn't often see AA cells, but everyone had a box of D cells in the fridge to feed flashlights. Most things wanted too much power for AA's (especially in the old carbon/zinc days) to have a useful life.
I used an avo 8, various marks from 1980 to 2000, and still have one. repaired photographic electronic flashunits an analog meter was always ideal for this. love the hack for 15v battery, I also have a Triplett 630PL that requires a 30v battery. avo 8 for me was an expensive but functional tool, I think the last price I saw at RS components was about 750 quid, good meter though
Beautiful bit of kit, thanks for this video Mike. I'd almost want to pick one of these up for nostalgia's sake but I can't afford to go down that road... the garage is already full to capacity with stuff I hardly use!
Yes these meters were the Rolls Royce of their day, and cost a weeks wages in the early 70s. Mine is AVO 8 mk2 made in 1956 I believe. Thanks for a look at the more modern version. I'm giving mine a renovation, nothing that will reduce its collectors value.
Great meter's, I still occasionally use a 50's model I picked up years ago. They're very responsive, and you can see the values at a glance. And now I think the high resistance range will be coming back to life thanks with some 2032's.
PLUS.... if you turn an AVO upside down they look like a Robot's face smiling up at you... which always cheers me up when things are proving a bit hard to work out
Wonderful meter - this was the rolls royce of multimeters back in the day - very accurate and dependable - the only disadvantage of a digital is the lower input impedance which can affect results on electronic circuits
Late 1980's to 2000 more likely, the 1970's versions had wires and a lot of them, along with the variable resistors being wound out of nichrome onto a former and then it's exact value being hand written onto the resistor on final test. You find resistors like 1734,8 ohms in these. Date will be a rubber stamp on the inside of the back cover, and on the boards.
AVO sold a 1.5 volt to 15 volt DC-DC converter that connects to the D cell. Supposed to drain the D cell after 1 year. I put a switch in line, on mine. Still working after 44 years, but not from the same cell!
Yeh, I remember there from teck (Technical College) and work in at Dept Civil Aviation. Thanks for this, brings some great memories (and some bad stuff-ups). That looks to be in near new condition. cheers
They still have their uses, an analogue scale is sometimes more practical if you're looking for a peak or a dip in a voltage, though I do mostly use a decent fluke or a high spec bench top meter these days.
The AVO 8 Mk. V does not have a Bakelite case, although older Mk. versions did use Bakelite. The Mk. V just used in injection molded plastic, not sure what flavor, might be polystyrene or perhaps ABS.
Nice meter, thanks for showing the internals too. 15 Volts battery unusual, I have seen the 22½ Volts battery which has the same size as the 9 Volts one. Clever idea to use the button cells to get 15V.
My 1983 Golf GTI had these flexible PCBs in the instrument pod. Some components were crimped directly on to the tracks. It always struck me as a very naff construction technique, but I had the car for 16 years and never had any trouble.
Not quite. A 1960s is more styled. The later ones has less kurved meter window and less design detail on the casing. The old ones are more a work of art where as the later ones are just industrial design the boring way. Avo 8 Mk IV and ealier are by far the most beautiful. www.richardsradios.co.uk/avo8.html
As I recall, the cutout functions if the needle hits the stop hard enough. Purely to prevent you breaking the movement by overvoltage (whether you do it in voltage or current measurement). Visually that has almost nothing in common with older models internally (mine is from 1952, as I recall), quite fascinating how much they changed. All those trimmable PCB sections used to be hand-made wire wound resistors on a bar at the bottom. I'd love another Avo, but that's too nice for me to afford..
They still have uses, that 3kV range (2.5 on mine) is very useful if you lack an HV probe, and sometimes that sensitive needle is more useful than any DMM, it's faster than any bar graph going.
I have a Simpson 270. My dad has a 260. I mostly use a DMM but analog gauges are still, for some uses, more adequate than numeric displays, especially when you it is more important to see sudden changes in values rather than the value itself.
Honestly, apart from the battery comment the same can be said for digital multimeters. I've got a 23-year old Fluke 73 that has literally sat in a cupboard for 20 years and is still very well within calibration, just needed to have the battery terminals cleaned after the equally old battery leaked inside the - leakage protected - battery compartment.
I have Metra Blansko instrument (which I believe was made in mid thirties) that has this same UI with two big knobs, complete with service manual. What always puzzled me is that has some rather weird modes for the time: capacitance measurement (by placing the cap in series with AC outlet) and something akin to true-RMS voltage (which I still have no idea how works). Instead of meter reverse it can double the range with press of button and has some very clever overload protection.
Wonder what parts became unavailable.... Must be something for the meter itself?? Switches and components shouldn't be a problem. For the switches I'm even sure real switches like on older models are still available. Never been a fan of that way making such switches integrated in the PCB - always felt it is cheap and inferior. I've always liked analog meters. A few days ago I was dumpster diving and found an old Avo 8 Mk III dated February 1968 (50 years old sharp!). Only the meter itself but in pristine condition - only a few minor scratches from the dumpster - appears just about unused and literally not a spec of dust(!) But I had to do a minor repair. The cutout was tripped and it was impossible to get it reset. I guess it was faulty adjusted already at the factory as it appeared untampered and no loose screws. At some point in history it was tripped and the meter was then just left unused for "time to get it repaired". Found out it was very easy to adjust it so now it's working and I've set it as easily tripable I could. It's possible to reset it with the meter being horizontal but not vertical - pushing it there will release it. The old Mk. III is just absolutely gorgeous and IMHO way better than any late 70s/80s design. The materials the design the smell of the inside. A time capsule from a forgotten time where everything was simpler and (mostly) better (even though it was before I was born). Nice tip for the 15v battery! I thought just using a 12v would be fine if the adjustment allowed for it (which I guess it will). First though I have to clean the battery compartment. It's quite nasty but it'll clean up decently with vinegar. I'll remember wash with water afterwards to void acid corrosion - not much idea to replace alkaline corrosion with and ditto instead :-p
I used to work with a guy back in the late '90's who was truly dedicated to his Avo 8. He wouldn't buy a DMM as he reckoned that the Avo found leaky diodes and transistors where DMM's wouldn't.....
those flexies used to go open circuit at the solder terminations leading to very intermittent and frustrating operation. Later marques used proper pcbs. The flexies could also melt when you put your 10A range across the mains.....
classic . If you ever find an Avo valve tester they're getting very rare, would make an excellent teardown. And you'd make a good bit of cash on ebay selling it
The internals of the Mk3 AVO 8 are vastly different - I suspect the construcion changed when they re-arranged the minor controls on the case. Hillman Imps used flexible plastic printed circuits (made by Smiths) from mid-1969 onwards, so yes it existed and was produced in the UK in the 70s.
The mirror is to negate parallax error. when reading. Obviously not as portable as the new DMM's but very good if you do a lot of bench work.Plus you cant beat an analog for high speed circuits..Most DMM's dont react quick enough.
Simple idea for the 15V battery hack, I like it! :) Hopefully AVO8 owners can pick up CR2032s cheaply enough to make it worthwhile (I've seen the BLR121 for £5.94, or the same ones from Maplin for ten quid). I don't know what the £1.50-for-five CR2032s from eBay are like.
I think you rather underestimate the usefulness of AVO analogue multimeters. I use a Fluke too but find that there are instances where I can use one of my AVOs to measure components in situ on boards that digitals can't do. I pop those button cells in a piece of tube with a spacer to make the 15v battery but neater 😉
Nice. I like my AvoMeters. Unfortunately, my Model 9SX is still in pieces and needs putting back together, and my Model 8 MkV is duff since the movement broke :(.
Some of the ebay CR2032s are not great at applications with high pulse current demands. For a simple bias application like this they may be fine... Energizer, FDK (former Sanyo), Varta make excellent CR2032s but they are very expensive unless you can get them through the bulk channels.
You wouldn't use one these days. My university just threw out a boat load of them because they bought in some new DMMs. 20 years ago however, these were the best meters around. Even back in 2008 we used these in college because they were such a massive investment when they were new, you couldn't just throw them away on a whim.
You call them pants, but you can rely on them for voltage and current with no battery and after they've sat in a cupboard for 20 years. Treated properly they're probably the most trustworthy meter you'll ever use.
And like me I bet you won't appreciate them right now as much as you will in 20-30 years from now :) Absolutely *nothing* beats an AVO for carefully adjusting a trim pot, trim inductor or trim capacitor. The needle damping is close to godlike.
@@engjds it was a reply to a comment 11 years ago, before RUclips had threaded replies like these. Sort "newest first" and you'll see a comment from TheBananaPlug which is also probably a reply to the same comment I was replying to. I think the original's since been removed.
There's a blast from the past ! I used to work weekends in a repair shop in the 80's and every now and again the AVO8 would make an appearance, I can remember it had a big satchel like case leather case, and was treated with respect,unlike the digi meters which were thrown everywhere. Nice vid.
Loved this! I have an Avo 8, look brand new including leather case and leads. Enjoyed seeing what’s inside!
one thing that new users often get confused with and think it's faulty:
the meter cutout can only be reset when the meter is horizontal (flat on the bench)
Amazing, I never thought we would reach the day when technicians didn't understand parallax.
I have a great condition one of the model you have in the video and still use it for sudden fluctuating voltage changes like in communications receiver calibration, audio signal level checking and is far better at Ni-Cad/NiMH voltage battery level checks than a DMM. They looks great on the shelf just like the technicians had them back when I was at college in the 80s. It was my dream meter back then so does have some of sentimental value to me. They are built to last a lifetime.
In the US, we had the Simpson 260. Complete with a real Bakelite case. It didn't quite have the range of yours, but it didn't need an odd 15 volt battery either.
I think one other reason for D cells - back in the 60's when that was designed, you didn't often see AA cells, but everyone had a box of D cells in the fridge to feed flashlights. Most things wanted too much power for AA's (especially in the old carbon/zinc days) to have a useful life.
Thanks mike.This certainly brings back fond memories. You'r right about not letting it out of your sight. Getoff it's MINE. Thank's again.
What a beautiful piece if kit inside and out. I have no need for one at all, but such is desire. I’ll have it.
I used an avo 8, various marks from 1980 to 2000, and still have one. repaired photographic electronic flashunits an analog meter was always ideal for this. love the hack for 15v battery, I also have a Triplett 630PL that requires a 30v battery. avo 8 for me was an expensive but functional tool, I think the last price I saw at RS components was about 750 quid, good meter though
Beautiful bit of kit, thanks for this video Mike. I'd almost want to pick one of these up for nostalgia's sake but I can't afford to go down that road... the garage is already full to capacity with stuff I hardly use!
Thanks Mike,
Always wanted one of these when I could not afford one. Nice hack on the battery.
Enjoying your vids as always.
My AVO 8 mk5 has a 1985 date code. A thing of beauty. Hardly ever use it; just haven't had the heart to sell it.
Yes these meters were the Rolls Royce of their day, and cost a weeks wages in the early 70s. Mine is AVO 8 mk2 made in 1956 I believe. Thanks for a look at the more modern version. I'm giving mine a renovation, nothing that will reduce its collectors value.
Great meter's, I still occasionally use a 50's model I picked up years ago. They're very responsive, and you can see the values at a glance. And now I think the high resistance range will be coming back to life thanks with some 2032's.
me to. I have the mk2
PLUS.... if you turn an AVO upside down they look like a Robot's face smiling up at you... which always cheers me up when things are proving a bit hard to work out
35 years of AVO use and I never noticed that before
Wonderful meter - this was the rolls royce of multimeters back in the day - very accurate and dependable - the only disadvantage of a digital is the lower input impedance which can affect results on electronic circuits
Late 1980's to 2000 more likely, the 1970's versions had wires and a lot of them, along with the variable resistors being wound out of nichrome onto a former and then it's exact value being hand written onto the resistor on final test. You find resistors like 1734,8 ohms in these. Date will be a rubber stamp on the inside of the back cover, and on the boards.
thank you after 11 years
AVO sold a 1.5 volt to 15 volt DC-DC converter that connects to the D cell. Supposed to drain the D cell after 1 year. I put a switch in line, on mine. Still working after 44 years, but not from the same cell!
Yeh, I remember there from teck (Technical College) and work in at Dept Civil Aviation.
Thanks for this, brings some great memories (and some bad stuff-ups). That looks to be in near new condition.
cheers
I think that thing is a work of art.
They still have their uses, an analogue scale is sometimes more practical if you're looking for a peak or a dip in a voltage, though I do mostly use a decent fluke or a high spec bench top meter these days.
Cool! i Got an old AVO 8 Mk. III here. It's awesome!
Mikes videos are so great i click like before i even watch.
Classic ! ...... I still use one at work !!
Bakelite, phenolic and flexible PCBs - what a mix!
The AVO 8 Mk. V does not have a Bakelite case, although older Mk. versions did use Bakelite. The Mk. V just used in injection molded plastic, not sure what flavor, might be polystyrene or perhaps ABS.
We missed you Mike!
Nice meter, thanks for showing the internals too. 15 Volts battery unusual, I have seen the 22½ Volts battery which has the same size as the 9 Volts one.
Clever idea to use the button cells to get 15V.
They are STILL useful on occasions.
Morris
marinas also used flexible circuit boards on the instrument panel circa 1974
and Toyota corolla dash display unit too
My 1983 Golf GTI had these flexible PCBs in the instrument pod. Some components were crimped directly on to the tracks. It always struck me as a very naff construction technique, but I had the car for 16 years and never had any trouble.
Usable, and will last longer than the 5 year life of the 15V batteries, especially if you do not leave it on resistance with the leads shorted.
Shades of 260. I remember my father's Simpson he had in the garage. That was a great meter, apparently, in the late 70's.
I collect all avo test gear I have a mk 7 the last made,and model 2 need a modle 1 this was made of wood a real work of art
Cpuld you not have shown how to remove the case. Ive undone the two screws at the bottom but what retains the top?
Wow. That looks just like a 1960s AVO 8 on the outside, but bears no resemblance to one on the inside.
Not quite. A 1960s is more styled. The later ones has less kurved meter window and less design detail on the casing. The old ones are more a work of art where as the later ones are just industrial design the boring way. Avo 8 Mk IV and ealier are by far the most beautiful.
www.richardsradios.co.uk/avo8.html
As I recall, the cutout functions if the needle hits the stop hard enough. Purely to prevent you breaking the movement by overvoltage (whether you do it in voltage or current measurement).
Visually that has almost nothing in common with older models internally (mine is from 1952, as I recall), quite fascinating how much they changed. All those trimmable PCB sections used to be hand-made wire wound resistors on a bar at the bottom.
I'd love another Avo, but that's too nice for me to afford..
They still have uses, that 3kV range (2.5 on mine) is very useful if you lack an HV probe, and sometimes that sensitive needle is more useful than any DMM, it's faster than any bar graph going.
I have a Simpson 270. My dad has a 260. I mostly use a DMM but analog gauges are still, for some uses, more adequate than numeric displays, especially when you it is more important to see sudden changes in values rather than the value itself.
It got us to the moon.
I bet it was kinda cramped for 3 astonauts in that battery compartment
I remember my old mid-70s Atari TV game console had flexi PCBs in its joysticks. I imagine they were a NASA development...
terrible to work on, the mk 5 is the only mk to have this ,its not kapton tape melts very easly
Honestly, apart from the battery comment the same can be said for digital multimeters. I've got a 23-year old Fluke 73 that has literally sat in a cupboard for 20 years and is still very well within calibration, just needed to have the battery terminals cleaned after the equally old battery leaked inside the - leakage protected - battery compartment.
I have Metra Blansko instrument (which I believe was made in mid thirties) that has this same UI with two big knobs, complete with service manual. What always puzzled me is that has some rather weird modes for the time: capacitance measurement (by placing the cap in series with AC outlet) and something akin to true-RMS voltage (which I still have no idea how works). Instead of meter reverse it can double the range with press of button and has some very clever overload protection.
Wonder what parts became unavailable.... Must be something for the meter itself?? Switches and components shouldn't be a problem. For the switches I'm even sure real switches like on older models are still available. Never been a fan of that way making such switches integrated in the PCB - always felt it is cheap and inferior.
I've always liked analog meters. A few days ago I was dumpster diving and found an old Avo 8 Mk III dated February 1968 (50 years old sharp!). Only the meter itself but in pristine condition - only a few minor scratches from the dumpster - appears just about unused and literally not a spec of dust(!) But I had to do a minor repair. The cutout was tripped and it was impossible to get it reset. I guess it was faulty adjusted already at the factory as it appeared untampered and no loose screws. At some point in history it was tripped and the meter was then just left unused for "time to get it repaired". Found out it was very easy to adjust it so now it's working and I've set it as easily tripable I could. It's possible to reset it with the meter being horizontal but not vertical - pushing it there will release it. The old Mk. III is just absolutely gorgeous and IMHO way better than any late 70s/80s design. The materials the design the smell of the inside. A time capsule from a forgotten time where everything was simpler and (mostly) better (even though it was before I was born).
Nice tip for the 15v battery! I thought just using a 12v would be fine if the adjustment allowed for it (which I guess it will). First though I have to clean the battery compartment. It's quite nasty but it'll clean up decently with vinegar. I'll remember wash with water afterwards to void acid corrosion - not much idea to replace alkaline corrosion with and ditto instead :-p
I used to work with a guy back in the late '90's who was truly dedicated to his Avo 8. He wouldn't buy a DMM as he reckoned that the Avo found leaky diodes and transistors where DMM's wouldn't.....
Would make a nice retro bench meter. One extra meter is not a bad thing.
How do I measure the resistance when on the division scale
My 1980 VW bus has the same flexible circuitry in the dash, so a VDO origin makes sense.
I did my apprenticeship with one of those.
Brilliant! Thanks for sharing.
those flexies used to go open circuit at the solder terminations leading to very intermittent and frustrating operation. Later marques used proper pcbs. The flexies could also melt when you put your 10A range across the mains.....
classic . If you ever find an Avo valve tester they're getting very rare, would make an excellent teardown. And you'd make a good bit of cash on ebay selling it
The internals of the Mk3 AVO 8 are vastly different - I suspect the construcion changed when they re-arranged the minor controls on the case.
Hillman Imps used flexible plastic printed circuits (made by Smiths) from mid-1969 onwards, so yes it existed and was produced in the UK in the 70s.
Never had an Avo.. Still have my Simpson 260 though, Another classic VOM.
The mirror is to negate parallax error. when reading. Obviously not as portable as the new DMM's but very good if you do a lot of bench work.Plus you cant beat an analog for high speed circuits..Most DMM's dont react quick enough.
Simple idea for the 15V battery hack, I like it! :)
Hopefully AVO8 owners can pick up CR2032s cheaply enough to make it worthwhile (I've seen the BLR121 for £5.94, or the same ones from Maplin for ten quid). I don't know what the £1.50-for-five CR2032s from eBay are like.
More vintage please!
D cells were extremely common at that time. They were introduced in 1898 (according to Wikipedia).
Not sure it's kapton - looks like a more ordinary plastic.
4:38
I laughed so hard when i saw that. Why have i never thought of that lol. Nice one :D
I think you rather underestimate the usefulness of AVO analogue multimeters. I use a Fluke too but find that there are instances where I can use one of my AVOs to measure components in situ on boards that digitals can't do. I pop those button cells in a piece of tube with a spacer to make the 15v battery but neater 😉
Awesome!
Nice.
I like my AvoMeters. Unfortunately, my Model 9SX is still in pieces and needs putting back together, and my Model 8 MkV is duff since the movement broke :(.
Some of the ebay CR2032s are not great at applications with high pulse current demands. For a simple bias application like this they may be fine...
Energizer, FDK (former Sanyo), Varta make excellent CR2032s but they are very expensive unless you can get them through the bulk channels.
nice old unit!
The switches sound like they should be beeped over...
Those no longer in use batteries and cells always interested me, have you thought about doing a video on any of the weirder ones?
I have lots of these ...I collect them
So do I
The internals are far from ugly. If I had it, I'd change the case for clear perspex!
You wouldn't use one these days. My university just threw out a boat load of them because they bought in some new DMMs.
20 years ago however, these were the best meters around. Even back in 2008 we used these in college because they were such a massive investment when they were new, you couldn't just throw them away on a whim.
You would if you test retro gear, see other comments, plus that fast needle makes fault finding easier.
still use my one :)
You call them pants, but you can rely on them for voltage and current with no battery and after they've sat in a cupboard for 20 years. Treated properly they're probably the most trustworthy meter you'll ever use.
They still used these when I was at uni! (does that make me old? :(
Andrew Sparrow I'm in my third year of uni at the moment and we use them!
And like me I bet you won't appreciate them right now as much as you will in 20-30 years from now :)
Absolutely *nothing* beats an AVO for carefully adjusting a trim pot, trim inductor or trim capacitor. The needle damping is close to godlike.
Pretty..
With the help of avometer I measure the pumping head
They really had that kapton flex cable stuff in the 70s?
ما هى وظيفة الخاصيه ins
BTW, beautiful.
Pants ? Oh you mean those things you wear on your head when your sucking your thumb while testing a matsui TV with your tandy multimeter !
lol it's hefty
If you used one you would quickly realize why your comment is ill informed.
You'd rather a meter that's a total piece of shit but at least looks good? Jesus.
Try measuring a fluctuating signal on the AVO and then a Fluke 87 and then come back and tell us its shit.
@@engjds it was a reply to a comment 11 years ago, before RUclips had threaded replies like these. Sort "newest first" and you'll see a comment from TheBananaPlug which is also probably a reply to the same comment I was replying to. I think the original's since been removed.
Go back to sleep...