Oldie but a cutie - Page 1
Forum section: electronics / testgear

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 10, 2016, 04:27:39 am
content: Here's something cute for vacuum tube lovers.Vacuum tube gear really isn't my thing, but a buddy talked me into adopting what you see here.It's a Phaostron Model 777 VTVM made in South Pasadena, California . It has a 12AU7 and a 12AL5. A 1.5V "C" cell powers the ohms.The case is die cast with black hammertone finish and has an illuminated display which practically lights up the room...The 777 measures 6 inches wide 4.5 inches high and 3 inches deep. It weighs about 2Kg (4.4lbs).For something that dates back to 1956 this is a sharp looking piece of equipment.Apparently it was used in a physics lab somewhere.Almost looks like it came out of the box yesterday and doesn't look clunky weird like most 50's stuff...I calibrated the DC scale using my AD688 plus/minus 10V precision reference. It wasn't out by much, maybe .1 volt max.This won't see any real service, but will serve as eye candy...

author: radhaz
author_rank: Regular Contributor
timestamp: August 10, 2016, 05:17:14 am
content: I love seeing unusual old gear. Good for you for rescuing it.

author: VK5RC
author_rank: Unknown
timestamp: August 10, 2016, 06:27:21 am
content: Agree lovely eye candy,

author: joeqsmith
author_rank: Super Contributor
timestamp: August 10, 2016, 12:42:06 pm
content: QuoteThat's how they survive the drop test!Very nice looking meter.

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 10, 2016, 02:42:11 pm
content: Thanks for the replies thus far.I should have posted this pic to give a better idea as to the size of the Model 777.One cannot tell how small it really is from the closeup. Anyway, these normally do not sit onthe kitchen table. I am rearranging and cleaning up my work benches and hauled these upfrom the basement.The 777 is holding down the Fluke 8500A. Next to it is my homebrew plus/minus 5V to 20V power supplythat's getting close to 40 years old. Never had to fix it thus far. On top of the power supply isthe latest Nixie tube piece of gear, a Fairchild Model 7050 3.5 digit VOM. A better pic of the Fairchild7050 is in the "Let'see your Nixie tube equipment" thread.Last but not least is the Analog Devices AD688 Precision Reference chip. It is not as accurate asthe LTZ1000, but good enough for me. I do not need super precision (as of today)...Who knows, maybe tomorrow ?I forgot to mention that I have a copy of the service manual for the Phaostron 777.If anyone wants a copy, let me know by PM.

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 10, 2016, 09:09:49 pm
content: Here is what the inside of the 777 looks like. Very clean as it should be.There is no ventilation so no dust can get in. The lack of a fuse and two prongnon-polarized plug would never get UL/CSA or any country's approval today.Things were much different way back when this was made.

author: bitseeker
author_rank: Super Contributor
timestamp: August 11, 2016, 03:14:46 am
content: That's a beauty. At first glance, I thought it was a radio based on the aesthetics.

author: med6753
author_rank: Super Contributor
timestamp: August 11, 2016, 04:17:51 am
content: That's a nice VTVMYou may want to consider changing out those 2 caps. Plus lurking somewhere underneath there should be a selenium rectifier that you can substitute in a silicon diode.

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 11, 2016, 04:57:01 am
content: @med6753:I have a Dick Smith ESR tester and checked the Sprague "Atoms" cap. Surprisingly it's still OK but you're right, it should be changedat some point. I didn't take the unit apart yet, but when I do I'll certainly replace the ancient Selenium rectifier but leave it there by fakingthat it's still part of the circuit so so it looks original. I would restuff the cap while trying to keep the paper covering intact for the same reason.

author: bitseeker
author_rank: Super Contributor
timestamp: August 11, 2016, 05:02:38 am
content: I'm amazed that the battery terminals are also in such great condition. Someone really took care of this meter. Congrats on acquiring it.

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 11, 2016, 05:33:23 am
content: @bitseeker|:I got the 777 from the same buddy who gave me all the other stuff. It has been sitting in his basement workshop for years, but he knew enough to takethe batteries out of the four that he had before storing them. He has offered them to others, taken one or two to a few swap meets but nobody wanted them and couldn'teven give them away. If it doesn't have an led or lcd display, people just don't seem to care.I am loathing and despising you even more for that landfill comment in the other thread...

author: bitseeker
author_rank: Super Contributor
timestamp: August 11, 2016, 05:59:54 am
content: Whatcha mean? Pat and I were saving them from ultimately ending up in a landfill. No one else would bid on them (even on eBay, amazingly enough). As you said, so many people these days want colorful LCDs.Are you sure you don't want to save the next 5216A from a landfill? Count 'em, seven beautiful Nixie tubes in one enclosure!

author: Assafl
author_rank: Frequent Contributor
timestamp: August 11, 2016, 07:19:28 am
content: What a thing of beauty. They really focused on the display and layout.If the ESR is okay consider keeping the caps. Love those old Sprague caps and Made in Pasadena deserves a US made capacitor.

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 11, 2016, 06:34:46 pm
content: We shall put the ESR issue of the Sprague "Atoms" cap to rest with this pic.The value is 10MFD/150V.The ESR tester doesn't show a worst case value for 150V. The new standard is 100 and 250V.So, a 2.75 ohm reading would indicate it would need changing out.Since the display shows .90 ohms, it is well with acceptable limits for something of this vintage (late 1950's)The cap is good and will stay there until the unit needs repair. I don't intend to keep opening the case tomeasure the ESR every few months.Now, just keep commenting on how pretty/cute/beautiful/ etc. the 777 is and stop worrying about the Sprague cap...

author: Fungus
author_rank: Super Contributor
timestamp: August 11, 2016, 07:12:18 pm
content: Nice!(how much?)

author: bitseeker
author_rank: Super Contributor
timestamp: August 11, 2016, 07:35:22 pm
content: My first encounter with Phaeostron was with their analog panel meters. Not just functional, but elegant too. The 777 is another example of their ability to balance aesthetics and engineering.

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 11, 2016, 09:49:24 pm
content: @Fungus:You're going to hate me for this... It was FREE as was the Fairchild 7050, HP 5221A, Eldorado 1820, Fluke 8500A, Brunelle Function Generator and my 7704A Tektronix scope.Oh yeah, the Heathkit Transistor Curve Tracer.Here's two pix of the Phaostron in action with the Fairchild 7050 Nixie VOM for comparison.Yesterday I used my AD688 precision +/- 10.0000 V reference to calibrate the DC scale on the 777 as well as the Fairchild.The meter reads 21.5 but the camera angle shows it as a bit less. No real big deal.The 777 gets pretty warm without ventilation. The case acts as a crude but effective heatsink.Maybe I should attach some fins to it and make it look like a '57 Chevy or the 60's series Batmobile...

author: Martin.M
author_rank: Frequent Contributor
timestamp: August 12, 2016, 05:30:46 pm
content: The Design of that oldie is time less, very cutegreetingsMartin

author: Cubdriver
author_rank: Unknown
timestamp: August 13, 2016, 07:51:34 am
content: Quote from: Enigma-man on August 10, 2016, 02:42:11 pmWow! It's actually much tinier than I thought from my glance at the first picture. I paid attention to the meter and didn't notice the toggle switch on the power supply right next to it, and figured that it was one of those old VTVMs with the huge 5x7" meter movement that you can read from across the room. It's a cute little bugger, and certainly looks to be in excellent condition.-Pat

author: Cubdriver
author_rank: Unknown
timestamp: August 13, 2016, 07:58:25 am
content: Quote from: bitseeker on August 11, 2016, 05:59:54 amHell, I'll snag the next one too if the opportunity presents itself. I only have (well, will have; it's still in transit) one of them so far. They seem to like company.The little Triplett VFD meter arrived yesterday, but I haven't gotten a chance to photograph it yet. It seems a bit out of whack based on a quick comparison to the recently arrived DP 3500 and my Fluke 77. No luck yet finding a manual for less than I paid for the meter, so that search will go on for a while I think.-Pat

author: bitseeker
author_rank: Super Contributor
timestamp: August 13, 2016, 08:40:30 pm
content: Quote from: Cubdriver on August 13, 2016, 07:51:34 amAnd what appear to be 2mm banana jacks for the inputs.

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 13, 2016, 10:20:22 pm
content: When I started this thread, I didn't think it would be of much interest. Looks like I was wrong.@bitseeker:Yes, it has plastic 2mm jacks on the front. The function and range knobs are chrome plated. The zero and ohms adj. are metal too.I also have the original probes. When I first turned it on I thought it wasn't working when I shorted the probes on one of the ohmsranges. It turned out to be an open circuit in the red probe which was corrected.med6753 mentioned a hidden Selenium rectifier. It's not hidden at all. I looked the service manual and it showed a diode symbol labeledX1. I found where it was on the disassembly drawings and is shown below.I don't know if I will be able to find 60 volt bulbs. There are two wired in series right at the 120V line input. I could sub two white leds or blue onesalong with a dropping resistor when the time comes.As I mentioned in the original post, I am no fan of clunky, gronky, downright unappealing VTVM's from the '50's. This one is in a league of its own.Just to show how tiny it really is, here's me holding it in my right hand while trying to take a pic on my phone using my left hand. Had a hell of a time getting this pic.

author: bitseeker
author_rank: Super Contributor
timestamp: August 14, 2016, 12:01:04 am
content: Quote from: Enigma-man on August 13, 2016, 10:20:22 pmYeah, it's all your fault. But I don't think anyone minds the distraction.QuoteI concur.QuoteIt's a great size for a home lab. Most of my equipment is half rack-width to conserve space.

author: Enigma-man
author_rank: Regular Contributor
timestamp: August 14, 2016, 02:27:55 am
content: Remember that famous line in Jaws, "You're gonna need a bigger boat ?"Well... "You're gonna need a bigger shop" If you keep scoring Nixie equipment of the rack mount variety.

author: bitseeker
author_rank: Super Contributor
timestamp: August 14, 2016, 05:04:20 am
content: LOL, yeah. I've been fortunate to have survived with mostly half rack. Pat's the one who needs more space and, soon, a stronger foundation to hold up his lab.

author: Cubdriver
author_rank: Unknown
timestamp: August 14, 2016, 07:10:17 am
content: Quote from: bitseeker on August 14, 2016, 05:04:20 amWhat, are you implying that full rack width by about 20" deep by 14" tall and roughly 80 pounds or so total weight is an inefficient use of space for an instrument that can measure both ACandDC voltage, and resistance too?!?Oh, and it can also measure frequency, up to 300kc!! So there!-Pat

author: Cubdriver
author_rank: Unknown
timestamp: August 14, 2016, 07:11:28 am
content: AND there are handles to grab onto if there's a tornado!-Pat

author: Martin.M
author_rank: Frequent Contributor
timestamp: August 14, 2016, 07:48:32 am
content: Quote from: bitseeker on August 14, 2016, 05:04:20 amwhen 5 people stands in front of a radio you have also a half tonIs there all full of scopes there is no place to put the five persons...So there is no problem (I have some experience with BA test gears in the home, Pat knows that)greetingsMartin

author: VK5RC
author_rank: Unknown
timestamp: August 15, 2016, 12:00:44 pm
content: Pat you are wasting money again on such fancy new fangled equipment, I have never needed to measure both AC and DC ! Let alone in the same modest weight and compact piece of equipment. And what is this new parameter 'resistance'. Where is the meter dial?HiHiI had a bit of a chuckle, this made me remember how in all seriousness one of my radio club members recalled when built his first tube receiver a long time ago, he didn't have a voltmeter and he described how he could roughly tell the voltage by the 'kick' it gave you !!!!!