Within the last hour I have brought a SANWA YX360TRF analogue meter. Analogue meters are unbeatable for certain jobs (try tuning trimmers and ferrite slugs for smoke which is simple on an analogue but near impossible for digital meters). Also the SANWA has a zero centre capability. I have fluke and volcraft for day to day use but would love an AVO. Beautiful piece of kit which would be better off in appreciative hands.
There were loads of Avo's at college, back in the late 1960's, when I was studying C&G radio, tv and electronics. They often got overloaded / blown, by students. The college technician, would then repair them. I think your find that battery adapter, is made of 'Paxolin'. It's a hard, paper laminated, insulating material. Again, we used Paxolin a lot at college. Drilled holes in it, then pressed metal turret pins into the holes, followed by soldering electronic components / connecting wires onto the pins, to form an electronic circuit.
I still have a Model 7, with the steel back case. I was told it was tropicalized. The steel case has an earthing stud for screening. My other one is a Model 8 Mk 9. Both have mirror scales and are within 1% or better of my Fluke 75. Big and clumsy they are for everyday use, but if your workbench is big enough, just leave them connected all day long to the job in total confidence. A bullet-proof meter from my apprenticeship days, they were the top of for every day use. Good ones are about £50 or so.
You Philistine, it's a classic piece of "Art Deco" design. I remember using these in school! Lol, that dates me. That manual/handbook you linked to from Wikipedia looked like it was done in the '60s, judging by the print style.
I’ve worked for Avo\Megger in Dover for 25 years, and I am company historian. It’s a classic piece of test equipment, sold up until 2008. The date can be obtained from the serial number printed on the scale plate.
I have to say that it was impressive how accurate this was and it is nice to read from those huge swinging meters (bit like preferring a speedometer to a digital speed readout in a car) but it belongs in a museum to show how much better things are now.
It's all about the nuances of analogue meters. The way the needle wiggles when the voltages is varying can give you as much information as a cheap scope. :)
Agreed. The motion of the needle can be quite useful. That is why i built my own multimeter with both analog and digital readouts. i used a Fluke 87 for the digital, and a very old Fluke for the analog.
Nail hit on head. Having pulled 7 avos into working order (partly with spares from 2 others) they remind me a bit of an old nursery rhyme from years ago: 'When she was good, she was very very good, but when she was bad she was AWFUL!' Worst offender- leaf switches worn, maladjusted, or damaged with a women's nail file! Other usual suspects- damaged movement, loose, tight or chipped jewels, magnetic swarf jamming coil, scale plate warped and jamming against needle (yes, really!) rotary switch contacts misaligned and jamming against each other, switch cams gone loose and out of phase, distorted front panel from excess humidity causing casing screws to jam, shear, or not go in, have even had mildew growing in one instrument..
The Philpott, do you by any chance have the service manual for the Avo7's either Mk ? If so would you be willing to scan it and emailme a copy if that is possible
A beautiful example of electro-mechanical engineering. I still use my Avo 8 for initial checking on my valve amps - I somehow have more faith in one of these for higher voltages than a modern(ish) dmm.Great video by the way :)
I still have one of these and would not part with it. They are so useful and are not prone to strange frequencies as DVM's can be. You can watch small value capacitors discharging which would confuse a DVM. with undulating signals a DVM will be going nuts to lock on to a reading, analogue wins out with a visual display. As for the age, there is a date code on the meter faceplate that is partly from direct view by the case, situated above the Q control. There is a dedicated site on the web (cant recall where) that gives chapter and verse on these and dates the many variants too. My Mk7 IIRC 1952
Where I went to college, they still use these today. Not sure if they are the same ones, but they looked very simular and I seem to remember the AVO logo. Ofcourse they have the modern meters as well, but it's still funny how they still hang on to these 'dinosaurs' ;)
+Thoms 29c blimey, i thought my electronic course was outdated when the teacher had one of these on his bench in the middle 80's, they had a fluke bench meter which i never ever see anyone allowed to touch it, lol
I have a very old VOM, No brand on it that I can find, just a couple rows of plugs on a red board, a large meter, in a wooden case. When I got it, I pulled it apart and removed some old Winchester brand D cells. They were, of course dead, and at that time, I was working as a Gunsmith and had a table at most gun shows in the area. I put the batteries on my table, and some fellow fell in love with them and tried to talk me out of them. By the end of the show he ended up trading me a very nice little 2 Inch .38 SPCL Chief's Special by S&W. Still have the meter though.
Hiya, I think you'll find the D cell 'holder' was actually an adapter, as the original battery was discontinued, but I'm not 100% sure. My grandfather worked for AVO, I think on the design team, something quite senior anyway. I remember some sort of battery adapter for the AVO 8 being like gold dust. I've actually found some AVO patents online with my grandfathers name on them.
I seem to remember something similar about the battery adapter, will have a look inside my Avo 7, hope that there is no battery in it. Not been used for more than a decade.
i used one as an apprentice in the '90s so bought one on ebay a few yrs ago after a few glasses of wine as you do... didn't get leads or a case though :( it now resides in my sideboard looking rather good alongside other interesting nick nacks.
On a safety note, early units had a backbox made of aluminium with a black crackle finish. This is all well and good as phenolic boards are glued inside as insulation.... provided no-one has drilled out and replaced the rubber feet and attached new ones with self tappers. The spacial tolerances inside are pretty tight and it is possible to shove a screw straight into a shunt or coil and make the case live when testing.
The AVO 7 had a sensitivity of only 500 ohms/volt so on the 10 volt range it shunted the circuit with 5k ohms compared to 10M ohm for to-days meters or the AVO 8 which is 20,000 ohms per volt. The AVO 7s were basically designed for Electricians to use (Low impedance circuits) and the AVO 8s were designed for Technicians to use on high impedance circuits. (Radio, TVs etc)
The AVO MK7's were widely quoted, in many radio manufactures servicing instruction, as the meter to use when measuring and setting voltages etc; as these were the meters their radio engineers used when drawing up specifications.
My father bought me an AVO Model 7, in its leather case for my 15th birthday (hmm 1972) and working towards my electronics GSE. Still have it and, on occation, still use it for more indepth fault tracing, my newer digital being used for other testing, like fuses and lamps.
I remember DMM's being shunned by the pro's in favour of AVO's even as late as the 80's. At Energy Controls (WM) Ltd we had a steady stream of AVO's in for service and repair.
The AVO here has had a replacement back instruction panel fitted. Thorn took over AVO when Thorn took over Metal industries back in 1967, then, AVO was part of Metal Industries.
The top is home made. It is much newer than the rest of the meter. The original Bakelite tops were prone to cracking through the screw holes due to owners over tightening them.
On the dial of AVOMeters there are some hand written numbers.(Usually located to the right, below the mirror section) The last three indicate the manufacturing date. So 361 would be March 1961, for example.
+Julian Ilett Hmm.. That's a bit odd.. You usually find it right below the lower bakelite edge for the window opening. It should be visible from the outside. Maybe they put it elewhere on this model.
+Julian Ilett It may be under the case on the right side of the meter face (per my earlier post) or like so many electrical items they (Thorn Avo) may have moved it to a new location suggesting it is a late year model. I guess it could be anywhere if it is not showing on the meter scale
+Electricguy +Julian Ilett Hope I'm not interfering, but image at 10:35 there seems to be the numbers Electricguy is referring to. Used to love my Avo8
On the bottom left hand side of meter (11:29-12:15, 14:01) the text "Accuracy to B.S. 89 Industrial" is visible. I'm not terribly familiar with British Standards, but I believe that dates it to 1977, or later (based on a very quick and incomplete search for that standard's earliest date)? On the bottom right side of the meter (10:53-11:09) the text (a space) followed by a "7” is clearly visible. Some other text is visible, but not legible, in two locations on this side during these frames, which could be what the earlier commenter was referencing.
Ha, I have one of those, inherited from my great-grandfather. It's a Mk1, and kind of battle worn - he used it working as an aircraft mechanic. No case, but it still worked fine when I used it as a kind in the 90s. I'd guess mine is from the 50s, though I'll have to check the serial - it's with my parents at the moment.
I have a Avometer 7mark 2. no idea on when its made. I also have two GEC Selectest super K's from the 1960's. I use a digital meter mostly but I still use these old beasts often... I find them quite accurate for most jobs
My grandfather has a Roto Ranger, the original auto ranging multimeter. It was made in 1947, and has been serving him ever since, never needed a new part except a battery once in a while, and is one of the most accurate meters i have ever seen. It has a 0-50 microvolt range, and i have checked it with my Fluke digital meter, and it is accurate to about 1/10th of a microvolt. No digital multimeter will ever last 68 years!
I would not be too confident in that, I already own digital multimeters that are nearly 35 years old and I have vintage digital test gear even older still, working just as well as they did on day 1. I would not be terribly surprised if they are still working 30 years from now (granted, the more advanced test gear may well need recapping before then, but the multimeter has no electrolytic capacitors so it should do just fine.
Ethan Poole Well, that is new to me. I wouldn't think that digital meters would last that long, because my oldest one ever was 9 years old when it died due to a static discharge, but i imagine that really old digital meters wouldn't have such sensitive chips inside. The fact that you have working 35 year old digital meters changed my view of digital meters a bit, but i still prefer analog in most situations.
Have a farnell (240volt powered) digi-meter for accurate work myself. Quite amused at the instruction book which only guarantees specified accuracies once the unit has been warmed up for 30 minutes. Having opened it up it's well made and has dedicated adjustment pots for all the scales-impressive. Portable, it is not, but it is rather old. About 1970 i think.
I have an AVO 8 I bought at a car boot sale for only £15. It's in very good condition and as a very nice bonus I discovered it has the 15v inverter mod fitted! I've used them in the past so thought I'd grab it. I'm with Julian on the AVO. While I have great respect for this electrically rugged, reliable and accurate piece of history, I would not like to have to use it as my main meter. It's ergonomically horrible, bulky and cumbersome. The leads are stiff and heavy and aimed at electrical rather than electronic engineering, and the meter doesn't withstand drops well. I use my old Fluke dmm, it's so much more practical.
It was well made, and with less technology in todays standards. Machinists probably respect the "AvoMeter Model 7" or your said device construction. Love your videos! I have learned a lot watching them :)
Know this is an old thread, but just found it. I have an Avo 8 & an Avo Multiminor. Still in regular use, still accurate. Yes, I have various modern meters from the cheapo to high quality, but nothing has the pure quality of Avo.
Dunno why you wouldn't like to own such a piece of beauty! I've an Avo-8, and it's used very regularly. With a 50-microamp FS meter, it's ideal for watching an ultra-low-power microcontroller - even the mechanical cutout works fine, if it enters an interrupt routine when you're not expecting it. Price? My 8 cost me €45, reasonable condition, except it can only be zeroed when it's lying flat. They made a helluvalot of the 7's and the 8's, so you won't get a lot for it - £50 outside, I'd reckon. About 30 years ago, I overheard a couple of blokes at a radio amateur convention (Alexandra Palace, IIRC). They were bartering for gear, using Avo's as currency! But really, try using it carefully for awhile. Bet it grows on you.
really nice there's something about a wavering needle measuring a varying voltage take a look at the same on a digital meter and all you see is digits flickering all over the place that don't make any sense !
wow. yours is in immaculate condition. My one has its case but no cables and the copper battery contacts are corroded. I'd like to find out if it still works like yours. Great video!
The capacitance range was nothing more than an ohm meter (or reactance meter, to be more exact) function. It was calibrated to work with the standard mains frequency. An infinite capacitor would be an AC short circuit, so would pass the full AC voltage at the calibrated mains frequency. Lower capacitance values will divide the voltage with the meter shunt resistance and produce a lower reading. Because they used a low frequency and an often questionable "sine wave" wave shape on the power supply they weren't particularly accurate, and also could only measure moderately large capacitors. Motor start caps, for instance.
Julian, the serial number would tell you the date, looks like it might end in 1264? Which would date it to december 1964 (the last 3 or 4 digits of the serial number, usually separated by a - from the rest of the serial number will tell you the month and year)
I remember when i bought one of these in the 80s'. I was told they were fabulous and revered and the best thing, One of these was alwyas on the bench of the old electrical repairs and supply shop, testing batteries and bulbs, from the 50's to the 90's, so a memory of my chiildhood too, but when i used one, I hated it to death! and hated analogue meters because of it, a couple of years later when i recovered finances and bought a DMM i never went back, these should be a distant memory of the 1950's! That lead set was the same lead set supplied new in the 80's i remember paying about 25 quid for a new set, horribly heavy and stiff, sorry, no love from me to this avo! The 7 was the general purpose unit, which most tv repair men used for valves back in the day, and the Model 40 which was used by many electricians and had a couple less ranges but more suited ranges for mains and 3 phase work. Value, about £30 to someone who likes them.
+Julian Ilett Oddly I am just the opposite, a DMM always makes me wonder if the voltage is really there or not (yes I know you can get ones with low input impedence,) but for general purpose use, analog is far better :p
It is quite the bodge job. I wouldn't mind one for my meter collection I suppose. I'll never find one on this side of the pond though. Here it is all Simpson and Triplett. With perhaps a smattering of Weston thrown in for good measure. Old meters are fairly worthless in my experience with them. I pay anywhere from $3 to maybe $20 for them depending on what they are. Which is why they're fun to collect. They're certainly cheap enough.
AVO made a whole range of interesting electronic test gear apart from multimeters... mainly valve based; however their is little or nothing on-line detailing this equipment. Mostly just about the multimeters. I have an interesting AVO Type 1388 B if anyone knows anything about it?. Also an AVO ETM, a couple of VCM valve testers... oh, and an AVO 8 :) It's high time someone (perhaps an ex employee of AVO) could put something on-line about this iconic British ground breaking company and its extensive products.
I have to agree this technology, while good in it's day, should have taken a bow in the 1950's. I take the fact it was produced well into the 80's to be a very British thing. Now (for those of you out there), don't get me wrong: I'm very much aware of the niche circumstances where, experience with this model multimeter, will yield a correct fault finding diagnose quicker than with any combination of modern equipment. However this is a mute point in the current service industry (or what's left of it).
My goodness, so much love for a calibration sticker that means remarkably little! All it tells one is that this meter met its manufacturer's specification for accuracy (and tolerances) back in 1982...which tells one exactly nothing about 2015. That said, with a little elbow grease the sticker can be fully removed, so it has little bearing on the meter's value. That said, I do not know of many people who buy vintage test gear based upon the physical condition of ancient calibration stickers, but if you are among those few, please rest assured that there will be other intact calibrations stickers to be found! Happy hunting!
Within the last hour I have brought a SANWA YX360TRF analogue meter. Analogue meters are unbeatable for certain jobs (try tuning trimmers and ferrite slugs for smoke which is simple on an analogue but near impossible for digital meters). Also the SANWA has a zero centre capability. I have fluke and volcraft for day to day use but would love an AVO. Beautiful piece of kit which would be better off in appreciative hands.
for me, that meter is a beauty
There were loads of Avo's at college, back in the late 1960's, when I was studying C&G radio, tv and electronics.
They often got overloaded / blown, by students. The college technician, would then repair them.
I think your find that battery adapter, is made of 'Paxolin'. It's a hard, paper laminated, insulating material.
Again, we used Paxolin a lot at college. Drilled holes in it, then pressed metal turret pins into the holes, followed by soldering electronic components / connecting wires onto the pins, to form an electronic circuit.
Beautiful piece of work, that...
I still have a Model 7, with the steel back case. I was told it was tropicalized. The steel case has an earthing stud for screening. My other one is a Model 8 Mk 9. Both have mirror scales and are within 1% or better of my Fluke 75. Big and clumsy they are for everyday use, but if your workbench is big enough, just leave them connected all day long to the job in total confidence. A bullet-proof meter from my apprenticeship days, they were the top of for every day use. Good ones are about £50 or so.
You Philistine, it's a classic piece of "Art Deco" design. I remember using these in school! Lol, that dates me. That manual/handbook you linked to from Wikipedia looked like it was done in the '60s, judging by the print style.
I’ve worked for Avo\Megger in Dover for 25 years, and I am company historian. It’s a classic piece of test equipment, sold up until 2008. The date can be obtained from the serial number printed on the scale plate.
Mine has serial number 2876-A-248, and doesn't have the two terminals near the meter.
And sometimes an apart number e.g. 261 which is Feb 1961.
this was the first meter I used at work as an apprentice at GEC Traction in Manchester - 1977
I have to say that it was impressive how accurate this was and it is nice to read from those huge swinging meters (bit like preferring a speedometer to a digital speed readout in a car) but it belongs in a museum to show how much better things are now.
It's all about the nuances of analogue meters. The way the needle wiggles when the voltages is varying can give you as much information as a cheap scope. :)
*voltage
Agreed. The motion of the needle can be quite useful. That is why i built my own multimeter with both analog and digital readouts. i used a Fluke 87 for the digital, and a very old Fluke for the analog.
+ParedCheese I would hate to be without my old Multimeter, it might be 31years old and not used often but in some respects analogue is easier to read.
Nail hit on head. Having pulled 7 avos into working order (partly with spares from 2 others) they remind me a bit of an old nursery rhyme from years ago: 'When she was good, she was very very good, but when she was bad she was AWFUL!'
Worst offender- leaf switches worn, maladjusted, or damaged with a women's nail file!
Other usual suspects- damaged movement, loose, tight or chipped jewels, magnetic swarf jamming coil, scale plate warped and jamming against needle (yes, really!) rotary switch contacts misaligned and jamming against each other, switch cams gone loose and out of phase, distorted front panel from excess humidity causing casing screws to jam, shear, or not go in, have even had mildew growing in one instrument..
The Philpott, do you by any chance have the service manual for the Avo7's either Mk ? If so would you be willing to scan it and emailme a copy if that is possible
A beautiful example of electro-mechanical engineering. I still use my Avo 8 for initial checking on my valve amps - I somehow have more faith in one of these for higher voltages than a modern(ish) dmm.Great video by the way :)
I still have one of these and would not part with it.
They are so useful and are not prone to strange frequencies as DVM's can be. You can watch small value capacitors discharging which would confuse a DVM. with undulating signals a DVM will be going nuts to lock on to a reading, analogue wins out with a visual display. As for the age, there is a date code on the meter faceplate that is partly from direct view by the case, situated above the Q control.
There is a dedicated site on the web (cant recall where) that gives chapter and verse on these and dates the many variants too. My Mk7 IIRC 1952
Where I went to college, they still use these today. Not sure if they are the same ones, but they looked very simular and I seem to remember the AVO logo. Ofcourse they have the modern meters as well, but it's still funny how they still hang on to these 'dinosaurs' ;)
+Thoms 29c blimey, i thought my electronic course was outdated when the teacher had one of these on his bench in the middle 80's, they had a fluke bench meter which i never ever see anyone allowed to touch it, lol
I have a very old VOM, No brand on it that I can find, just a couple rows of plugs on a red board, a large meter, in a wooden case. When I got it, I pulled it apart and removed some old Winchester brand D cells. They were, of course dead, and at that time, I was working as a Gunsmith and had a table at most gun shows in the area. I put the batteries on my table, and some fellow fell in love with them and tried to talk me out of them. By the end of the show he ended up trading me a very nice little 2 Inch .38 SPCL Chief's Special by S&W. Still have the meter though.
Hiya, I think you'll find the D cell 'holder' was actually an adapter, as the original battery was discontinued, but I'm not 100% sure. My grandfather worked for AVO, I think on the design team, something quite senior anyway. I remember some sort of battery adapter for the AVO 8 being like gold dust. I've actually found some AVO patents online with my grandfathers name on them.
I seem to remember something similar about the battery adapter, will have a look inside my Avo 7, hope that there is no battery in it. Not been used for more than a decade.
i used one as an apprentice in the '90s so bought one on ebay a few yrs ago after a few glasses of wine as you do... didn't get leads or a case though :(
it now resides in my sideboard looking rather good alongside other interesting nick nacks.
God, this makes me feel old. My first (work) meter was an Avo 8, the standard for the time.
Great memories. Thanks (I think).
On a safety note, early units had a backbox made of aluminium with a black crackle finish. This is all well and good as phenolic boards are glued inside as insulation.... provided no-one has drilled out and replaced the rubber feet and attached new ones with self tappers. The spacial tolerances inside are pretty tight and it is possible to shove a screw straight into a shunt or coil and make the case live when testing.
My grand dad actually supposedly stole one of these from the navy back in the 1960's and I still have it today!
The AVO 7 had a sensitivity of only 500 ohms/volt so on the 10 volt range it shunted the circuit with 5k ohms compared to 10M ohm for to-days meters or the AVO 8 which is 20,000 ohms per volt. The AVO 7s were basically designed for Electricians to use (Low impedance circuits) and the AVO 8s were designed for Technicians to use on high impedance circuits. (Radio, TVs etc)
The AVO MK7's were widely quoted, in many radio manufactures servicing instruction, as the meter to use when measuring and setting voltages etc; as these were the meters their radio engineers used when drawing up specifications.
My father bought me an AVO Model 7, in its leather case for my 15th birthday (hmm 1972) and working towards my electronics GSE. Still have it and, on occation, still use it for more indepth fault tracing, my newer digital being used for other testing, like fuses and lamps.
Ohh, nice meter. DMMs should respect their elders!
+DextersLab2013 Youngster to day, ahy, they think they know it all !!!!
They definitely should. What's more, you can't do weight training with a digi fluke in each hand.. !
I remember DMM's being shunned by the pro's in favour of AVO's even as late as the 80's. At Energy Controls (WM) Ltd we had a steady stream of AVO's in for service and repair.
The AVO here has had a replacement back instruction panel fitted. Thorn took over AVO when Thorn took over Metal industries back in 1967, then, AVO was part of Metal Industries.
The top is home made. It is much newer than the rest of the meter. The original Bakelite tops were prone to cracking through the screw holes due to owners over tightening them.
On the dial of AVOMeters there are some hand written numbers.(Usually located to the right, below the mirror section) The last three indicate the manufacturing date. So 361 would be March 1961, for example.
+Electricguy Hmm, I can't see anything written on this one - not from the outside anyway.
+Julian Ilett Hmm.. That's a bit odd.. You usually find it right below the lower bakelite edge for the window opening. It should be visible from the outside. Maybe they put it elewhere on this model.
+Julian Ilett It may be under the case on the right side of the meter face (per my earlier post) or like so many electrical items they (Thorn Avo) may have moved it to a new location suggesting it is a late year model. I guess it could be anywhere if it is not showing on the meter scale
+Electricguy +Julian Ilett Hope I'm not interfering, but image at 10:35 there seems to be the numbers Electricguy is referring to. Used to love my Avo8
On the bottom left hand side of meter (11:29-12:15, 14:01) the text "Accuracy to B.S. 89 Industrial" is visible. I'm not terribly familiar with British Standards, but I believe that dates it to 1977, or later (based on a very quick and incomplete search for that standard's earliest date)?
On the bottom right side of the meter (10:53-11:09) the text (a space) followed by a "7” is clearly visible. Some other text is visible, but not legible, in two locations on this side during these frames, which could be what the earlier commenter was referencing.
You call it retro, but we use same meter only from Russian manufacturer made in 60's at my university nowadays.
And that's how you break a perfectly good case.... you don't pull out... you slide out from the top (or bottom from the looks of yours)
Gotta love those old meters, once had the pleasure of using a MEGA meter that generated high voltage got a few shocks of that one lol
you're thinking of a megger insulation resistance tester.
yes
The last four digits of the serial number give the age - month/year
Serial should be on right side of meter scale
In the 80's thats what we had in the RAF
Must have been as aerodynamic as a brick? Nightmare to fly.
Ha, I have one of those, inherited from my great-grandfather. It's a Mk1, and kind of battle worn - he used it working as an aircraft mechanic. No case, but it still worked fine when I used it as a kind in the 90s. I'd guess mine is from the 50s, though I'll have to check the serial - it's with my parents at the moment.
I have a Avometer 7mark 2. no idea on when its made. I also have two GEC Selectest super K's from the 1960's. I use a digital meter mostly but I still use these old beasts often... I find them quite accurate for most jobs
My grandfather has a Roto Ranger, the original auto ranging multimeter. It was made in 1947, and has been serving him ever since, never needed a new part except a battery once in a while, and is one of the most accurate meters i have ever seen. It has a 0-50 microvolt range, and i have checked it with my Fluke digital meter, and it is accurate to about 1/10th of a microvolt. No digital multimeter will ever last 68 years!
I would not be too confident in that, I already own digital multimeters that are nearly 35 years old and I have vintage digital test gear even older still, working just as well as they did on day 1. I would not be terribly surprised if they are still working 30 years from now (granted, the more advanced test gear may well need recapping before then, but the multimeter has no electrolytic capacitors so it should do just fine.
Ethan Poole Well, that is new to me. I wouldn't think that digital meters would last that long, because my oldest one ever was 9 years old when it died due to a static discharge, but i imagine that really old digital meters wouldn't have such sensitive chips inside. The fact that you have working 35 year old digital meters changed my view of digital meters a bit, but i still prefer analog in most situations.
Have a farnell (240volt powered) digi-meter for accurate work myself. Quite amused at the instruction book which only guarantees specified accuracies once the unit has been warmed up for 30 minutes. Having opened it up it's well made and has dedicated adjustment pots for all the scales-impressive.
Portable, it is not, but it is rather old. About 1970 i think.
I have an AVO 8 I bought at a car boot sale for only £15. It's in very good condition and as a very nice bonus I discovered it has the 15v inverter mod fitted! I've used them in the past so thought I'd grab it.
I'm with Julian on the AVO. While I have great respect for this electrically rugged, reliable and accurate piece of history, I would not like to have to use it as my main meter. It's ergonomically horrible, bulky and cumbersome. The leads are stiff and heavy and aimed at electrical rather than electronic engineering, and the meter doesn't withstand drops well. I use my old Fluke dmm, it's so much more practical.
It was well made, and with less technology in todays standards. Machinists probably respect the "AvoMeter Model 7" or your said device construction. Love your videos! I have learned a lot watching them :)
Know this is an old thread, but just found it. I have an Avo 8 & an Avo Multiminor. Still in regular use, still accurate. Yes, I have various modern meters from the cheapo to high quality, but nothing has the pure quality of Avo.
Dunno why you wouldn't like to own such a piece of beauty!
I've an Avo-8, and it's used very regularly. With a 50-microamp FS meter, it's ideal for watching an ultra-low-power microcontroller - even the mechanical cutout works fine, if it enters an interrupt routine when you're not expecting it.
Price? My 8 cost me €45, reasonable condition, except it can only be zeroed when it's lying flat. They made a helluvalot of the 7's and the 8's, so you won't get a lot for it - £50 outside, I'd reckon.
About 30 years ago, I overheard a couple of blokes at a radio amateur convention (Alexandra Palace, IIRC). They were bartering for gear, using Avo's as currency!
But really, try using it carefully for awhile. Bet it grows on you.
^^^^^ wot he said.
really nice there's something about a wavering needle measuring a varying voltage take a look at the same on a digital meter and all you see is digits flickering all over the place that don't make any sense !
wow. yours is in immaculate condition. My one has its case but no cables and the copper battery contacts are corroded. I'd like to find out if it still works like yours. Great video!
The capacitance range was nothing more than an ohm meter (or reactance meter, to be more exact) function. It was calibrated to work with the standard mains frequency. An infinite capacitor would be an AC short circuit, so would pass the full AC voltage at the calibrated mains frequency. Lower capacitance values will divide the voltage with the meter shunt resistance and produce a lower reading.
Because they used a low frequency and an often questionable "sine wave" wave shape on the power supply they weren't particularly accurate, and also could only measure moderately large capacitors. Motor start caps, for instance.
I have this avometer, it still have one 1.5 volt battery, its everready r1662 wrap in paper box date 1 Oct 1971 . 😁😁😁
Julian, the serial number would tell you the date, looks like it might end in 1264? Which would date it to december 1964 (the last 3 or 4 digits of the serial number, usually separated by a - from the rest of the serial number will tell you the month and year)
Please can this meter use for earth geophysical survivors
I remember when i bought one of these in the 80s'. I was told they were fabulous and revered and the best thing, One of these was alwyas on the bench of the old electrical repairs and supply shop, testing batteries and bulbs, from the 50's to the 90's, so a memory of my chiildhood too, but when i used one, I hated it to death! and hated analogue meters because of it, a couple of years later when i recovered finances and bought a DMM i never went back, these should be a distant memory of the 1950's! That lead set was the same lead set supplied new in the 80's i remember paying about 25 quid for a new set, horribly heavy and stiff, sorry, no love from me to this avo! The 7 was the general purpose unit, which most tv repair men used for valves back in the day, and the Model 40 which was used by many electricians and had a couple less ranges but more suited ranges for mains and 3 phase work. Value, about £30 to someone who likes them.
+jusb1066 Yeah, can't say I'm sad to have to return this to its owner.
+Julian Ilett Oddly I am just the opposite, a DMM always makes me wonder if the voltage is really there or not (yes I know you can get ones with low input impedence,) but for general purpose use, analog is far better :p
It is quite the bodge job. I wouldn't mind one for my meter collection I suppose. I'll never find one on this side of the pond though. Here it is all Simpson and Triplett. With perhaps a smattering of Weston thrown in for good measure. Old meters are fairly worthless in my experience with them. I pay anywhere from $3 to maybe $20 for them depending on what they are. Which is why they're fun to collect. They're certainly cheap enough.
Thanks for giving us all the middle finger @1:02 lol
AVO made a whole range of interesting electronic test gear apart from multimeters... mainly valve based; however their is little or nothing on-line detailing this equipment. Mostly just about the multimeters. I have an interesting AVO Type 1388 B if anyone knows anything about it?. Also an AVO ETM, a couple of VCM valve testers... oh, and an AVO 8 :) It's high time someone (perhaps an ex employee of AVO) could put something on-line about this iconic British ground breaking company and its extensive products.
Was brought up on the AVO 7
ART
Remember kids... this was in the era before the smily was invented.
Bottom left of the meter pannel
That looks like something my granddad had in his shed.
My father has the smaller version of this, a bit chunky and heavy, for sure I wouldn't carry it in my bag as a backup tool lol.
We've come a long ways...
that meter is far better product than your modern rubbish
The top looks like a replacement plate.
I have to agree this technology, while good in it's day, should have taken a bow in the 1950's. I take the fact it was produced well into the 80's to be a very British thing.
Now (for those of you out there), don't get me wrong: I'm very much aware of the niche circumstances where, experience with this model multimeter, will yield a correct fault finding diagnose quicker than with any combination of modern equipment. However this is a mute point in the current service industry (or what's left of it).
looks like an 18th century piece of device.
and now i badly want one AMM. :/
Fungus ridden box, unfortunately mould is not uncommon in UK.
tengo uno igual pero no anda. saludos
(2:50) - That lid does not look original.
>
Heath Robinson must be the equivalent of Rube Goldberg.
Breaks my heart that you broke the old calibration sticker and dug out that gunk in the one hole for a silly little youtube video.
+pikadroo You'll get over it petal.
My goodness, so much love for a calibration sticker that means remarkably little! All it tells one is that this meter met its manufacturer's specification for accuracy (and tolerances) back in 1982...which tells one exactly nothing about 2015. That said, with a little elbow grease the sticker can be fully removed, so it has little bearing on the meter's value. That said, I do not know of many people who buy vintage test gear based upon the physical condition of ancient calibration stickers, but if you are among those few, please rest assured that there will be other intact calibrations stickers to be found! Happy hunting!
Know your subject before talking about. Destroyed value in it my taking it apart and introducing dust.
Was mint until you F*****d with it.
Why make a video when you don’t know the subject. I couldn’t watch it.
Makes me cringe too I collect avometer test gear
Is it cool to be so vauge