Forums :: Resources :: Features :: Photo Gallery :: Vintage Radio Shows :: Archives :: Books
Support This Site: Contributors :: Advertise


It is currently Oct Sat 25, 2014 3:33 pm


All times are UTC [ DST ]



Post New Topic Post Reply  [ 27 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similarities
PostPosted: Nov Sat 19, 2011 12:34 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 1541
Location: Oswego, NY, USA
Deleted


Last edited by Fred Scoles on Nov Tue 22, 2011 6:23 am, edited 1 time in total.

Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Nov Sat 19, 2011 1:14 am 
Member
User avatar

Joined: May Mon 18, 2009 5:55 pm
Posts: 2462
Location: Erie, PA
....as I was getting all pumped up for another fascinating VOM debate :P

Happy Thanksgiving to you too! :D

_________________
My Current Projects:
http://www.facebook.com/#!/pages/Marks- ... 4487855125


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Nov Sat 19, 2011 2:02 am 
Member
User avatar

Joined: May Wed 18, 2011 2:40 am
Posts: 1382
Location: Littleton, MA
MarkPalmer wrote:
....as I was getting all pumped up for another fascinating VOM debate :P

Don't want to disappoint you Mark :-)

I used to think the Triplett meters were ugly, and only liked the Simpson 260/270's. I had never seen a real Triplett in the flesh, just photos in old Allied and Lafayette catalogs. I guess I must have been thinking of the vanilla 630's, because a couple of months back I stumbled over a gorgeous Triplett 630-PL with 639-N carrying case at the MIT flea and I could not resist buying it. I love the luscious maroon knob and that huge meter. I dreamt about it for days afterward. No, seriously :-) I even felt bad about negotiating down the price on it :-) Now it's my favorite analog meter.

Best regards,
-Steve


Attachments:
Triplett_630_and_Simpson_260.jpg
Triplett_630_and_Simpson_260.jpg [ 44.24 KiB | Viewed 2882 times ]

_________________
Steve Byan http://www.byan-roper.org/steve/steve-at-play/
Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Nov Sat 19, 2011 2:12 am 
Member
User avatar

Joined: May Mon 18, 2009 5:55 pm
Posts: 2462
Location: Erie, PA
I had a Triplett 64 FET-VOM that was a very respectable, well made meter. I ended up selling it as I wasn't using it, but now that I have quite a collection of multimeters including several Simpson 260's, I regret selling that Triplett as the 64 isn't all to common to come across today. I think the 30 volt battery thing, even though easy deal with, has shied me away from the older TTT's.

-Mark-

_________________
My Current Projects:
http://www.facebook.com/#!/pages/Marks- ... 4487855125


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Nov Sun 20, 2011 5:13 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 3550
Location: Harviell MO USA 63945 (12 miles S of Poplar Bluff)
The Knight-Kit 20Kohm/v VOM has many of the design similarities of the Triplett 630 -- Allied even got the meter movement (I suspect with the scale also) from Triplett. Because of one design flaw in the K-K/Triplett, I can comment on one difference that's significant: notice that the Triplett has a switch setting for the 10A current range while the Simpson has you move the banana plugs to special 10A jacks. The 10A shunt is directly across those 10A jacks while the contact within the function/range switch of the Triplett is part of the 10A circuit. If you accidentally overload the meter on the 10A range, you can blow the contact on the switch to smithereens. I did that with the K-K and have to live without that 10A range -- no big deal, really. Just irritating.

_________________
Dean, Electronics Curmudgeon
Contributing editor emeritus in Poptronics magazine, R.I.P.


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Nov Sun 20, 2011 5:57 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 1541
Location: Oswego, NY, USA
Deleted


Last edited by Fred Scoles on Nov Tue 22, 2011 6:22 am, edited 1 time in total.

Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Nov Mon 21, 2011 12:46 am 
Member
User avatar

Joined: May Wed 18, 2011 2:40 am
Posts: 1382
Location: Littleton, MA
So I've been trying to research the different classic Triplett 630-series VOMs, but I'm confused over the line-up. What are the various models, and what's the difference between them?

I see Triplett (now Jewell) is still selling the plain "630". They say it has "25 ranges". My 1965 Lafayette catalog also lists a 630A, which is a higher-precision version of the plain 630.

The 630-PL (and 630-PLK, the version of the 630-PL with a protection circuit, and the high-accuracy 630-APL), with 28 ranges comes in a case that's more attractive to my eye, but otherwise seems similar to the 630. Why two similar models (630 and 630-PL)? My 1965 Allied catalog evens lists them at the same price. Is the 630 in a bakelite case, with the 630-PL in an injection-molded thermoplastic case?

The 630-NA looks to be the same case style as the PL, but with 58 ranges, including a "range doubler" switch.

The 630-NS looks similar to a 630-NS but with 200K ohms per volt sensitivity instead of 20K ohms per volt.

The 631 is an odd VTVM/VOM combination, in the 630-PL case style.

Were there any others?

Best regards,
-Steve

_________________
Steve Byan http://www.byan-roper.org/steve/steve-at-play/


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Nov Mon 21, 2011 2:34 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 1541
Location: Oswego, NY, USA
Deleted


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Nov Wed 23, 2011 6:44 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 1541
Location: Oswego, NY, USA
I had deleted a day ago my original answer to Steve's question above (what's the TTT VOM lineup???Steve asked us, which is a perfectly excellent question) simply because I got far too verbose and off track, so I had to delete it....soooorrrryyy bout that everyone......so I'm trying this again, and remember it is absolutely accurate in every detail, because from 1953 thru 1972 (when I left for college) I had lived in the midst of all my relatives going to work everyday at the meter works in Bluffton, and I currently am holder of all the known existing Triplett Engineering and Marketing records and files (Alan D......if you are interested, please PM or email to me so we can "chat" if you'd like all this information plus at least a day-long interview with me if you'd like to publish more books on the subject, as I simply don't have your expertise/God-given talents or the time to pull this off. Your certainly do have the skills to do this, as shown with your previous publications, which are for most of us ARF'ers our favorite hobby reading books, hands down.) So here's the TTT VOM Lineups:

The first Triplett Model 630, with the "curved-top" black, plain Bakelite case, was first introduced around Fall 1947 (Alan's book is more correct than I if he listed a more specific date..), specifically to replace model 625-N, which was good, of course, but very dated and it didn't keep up with Simpson's newly introduced series 260-1 VOM. This first TTT630 is what collectors call the "Red-Dot" as its mvt came with a "lifetime" garanty (Midwest pronounciation, as Past Pres Gerald R. Ford used to call it in Press Conferences on TV) and its insides have a unique bakelite resistor turret with the resistors in bakelite vertical wells, not at all like the 630's made after Sept. 1952 when the changeover was made (all Triplett bakelite cases were molded in Bluffton also at the old Page Dairy plant, because the smell made everybody sick and nautious is they molded along Riley CreeK (main plant). Triplett took great pride doing everything themselves; of course though the magnet wire was contracted from Belden, and the clear lucite arrived as blocks from Dupont, NJ. These earliest 630's were and are great performers and the pride of every Triplett collector's collection, but very few were ever made, because they didn't stop making the 625-N until about Fall 1955. Most Ebaye sellers don't know squat about Triplett, so you have to ask them to send you an internal picture to know what you're bidding on.

Now, let's get chronologically to the next VOM...the Model 630, also in the curved-top black bakelite case (or as another ARF'er quipped, the one with absolutely no sex-appeal); it's first production run was Sept. 1952, with every feature that was retained thru plant closing in '07, except they stopped hand wrapping and beeswaxing their own precision resistors about 1960, and contracted out to Dale/Vishay for precision one percent films after that. When Mike had me make 3 trips out to Bluffton 3 summers ago (I had to go anyway cause my oldest brother was dying of a brain tumor near TenMile TN, and his widow/my sister in law later that summer requested my wife and I to provide both his Eulogy and all his memorial services music and we are trained, degreed church musicians and that church, St. John's UCC, Bluffton is located 1 small town block from the old Triplett warehouses, so after the service I loaded up all the rest of the Triplett stuff and back to Oswego NY). That VOM also displayed the new 600OHM/1mw newly voted-in (by the Telephony workers union and RTMA) on dB scale, not the old 500 Ohm scale, which makes the oldies even that more valuable to collectors. Next, about late 1953, the first model 630-A was produced, which is a more precise, mirrored-scale 630 (1 percent mvt and resistors, instead of the normal 1.5 % resistors and the 2.5 % mvt....the movements are identical of course, it's just that the "A" received the #1 magged portion of each movement production run which assured the best linearity). Later and thru to '07 there were many, various varieties and production runs of other 630's such as Model 630-D for Bell Labs, and some of them have the Bell logos and are very, very collectible, and I have all the eng-files on all of them if Alan needs them for his next book/treatise. Mrs. Bosse, mom of my favorite best friend at Mr. Cory Elementary School (Mt. Cory, Ohio) Jeffrey...she was Triplett's only scale draftsman (BC/Before Computers, remember) and she drafted every scale thru those years. To this day, Jeff & his younger brother Jay Bosse and I are good friends. Jeff also has vivid memories of complete Triplett Corp. history. There were also many other "specials" of the classic TTT 630. By the way, the curved top Triplett logo, the older one you all see on Ebay, was designed (according to Mom, who dated Norman at the time) by Cleon's (Cleon Triplett was co-founder of Triplett in 1902 with his brother Ray) son Norman in late 1932, to completely replace their previous logo "Read-rite", and I have here all of the old factory 6 ft. tall handpainted Readrite signs in my collection. Sorry for getting off track.....back on again....

The next was MMT's (aka Marion Morris Triplett, or Morris to our familyl, or "Morrey" to his fellow engineers and to his family) new model 631 late April 1953 (combo VTVM/VOM, all batt operated, no need to plug it in, as it used a hexode mini DK91/IR5 in triode mode, which had been invented/introduced by Sylvania about 1 1/2 yrs prior to that for portable hearing aids. Today, the model 631 is highly useful and very collectible. I have four of them, and I had written for Triplett engineering in 2002, at their insistence a DIY article for their website describing how one can retrofit today's batteries to run it... but their new owners Jewell saw fit to can my article.....not nice guys!!!!!!!!!! If you need tech specs or engfiles on the 631, ask me. Next comes the model 630-L, which was the very first VOM having the "sexy-looking" big clear lucite window, with the large red "luscious" (as another ARFer wrote just last week) knob, and the "L" featured a "low power OHms" scales (not enough power to trigger forward biasing in either a Ge or Si chip) w/o any active components inside....quite a feat at the time...but to do that they had its Ohms scales running backwards, which drives most of us nuts to use this model. The "sexy-looking" 630's that all came after this came in such rapid fire off the engineer's desks that nobody knows what order they all went in to Production Number 1, they are: 630-PL a standard 50ua mvt 20K opv & 5K opv on ACV ranges (which is the United States standard meter-grade half wave bridge of that time), 630-NA ditto but was the very first of the series to have the little gray slide switch under the main knob, which simply kicked in the voltage divider network to proved double the number of ranges.....a very brilliant engineering feat. 630-PLK which is a PL but with the added overcurrent protection circuit which comprises their patented (none of simpson's or triplett's printed manuals ever told you what was inside this circuit, because it was Proprietary/Patented; I do have all the files on it, alan if you want them later) switching transistor sensing ckt that could trigger a big-ole relay off if you tried zapping it with something the meter didn't like. These Protection ckts worked as long as you don't get them near a high-tension power line or near high field RF's which will "fool" the sensing ckt every time, as documented in my Triplett folder from August 1970 by TTT engr. Mr. Carmack in his own handwriting. Mr. Carmack's handwriting also indicates that TTT simply copied Simpson's 260-4P protection ckt, ver batim without ever telling Simpson they did that. The 630-APLK is a PLK with the more precise mvt & resistors and a scale mirror....but by about 1976 they combined (to make more corporate profits and reduce distributor stocking demands)those two models into a model 630-PL which has the good resistors and the mirror....so, I guess "to Hell" with nomenclature and keep 'em in the dark, Ha, Ha!!!!! Next in line came the model 630-NS which is simply a model 630-NA visually and internally, but with the 5ua fs mvt for a native sensitivity of 200,000 opv DCV, and 100,000 opv DCV with the slider kicked in, these are hugely popular on Ebay, but you gotta be careful because most of them have lost much of their mvt's magnet field because to get it there TTT had to almost saturate those magnets, and the more you saturate a magnet, the easier it is for it to lose it over time, so be very careful...even the ns's on Ebay that say "Working..." are usually Not; so Beware...I personally know of only one Ebay seller who actually sells honestly good , calibrated 630-NS's, Mr. John Warner, of Fallon NV, John's a retired EE and was for years a research engineer for the U.S. Military, his specialty was development of Nuclear Warhead electronic fuse circuits and he periodically sells the NS's on Ebay....he's a known excellent gentleman, as is our own Mr. Alan Douglas. Next in line in the TTT 630's is model 630-M, which went thru only 2 production runs, and a total of six of them were ever made and according to Mr. Ropp Triplett (pres when I was growing up), only two of them got out the door to a distributor. Just last year on Ebay I bought the only surviving example of an "M" and it is in perfect, original condition....and it has no known $$$$ value assigned to it as I have the only known example in my collection. Simpson never ever had anything like it. My "M"'s native mvt is 1ua fs for 1 million Ohms per volt DCV, and 500,000 opv with the slider kicked to the Right (it looks identical to a 630-na or ns on the outside); inside it's totally different though simply because at that high sensitivity they could not use the regular bakelite resistor holder turrest because the bakelite attracted too much static and/or summer humity, so it as a special circuit board and white nylong sleeves around its panel jacks. I snagged it last yr off Ebay simply because I was the only soul on earth who even knew what it was.

Equally popular were TTT's (BTW, the year Mrs. Bosse retired in the late 1960's they had her design the famour TTT logo, which stands for the three principles at that time: Ropp and his brother Morris; and their first cousin Norman; as their respective Dad's Ray and his brother Cleon had either retired or passed by then.) a"Mighty Mites" all of the various miniature VOM's 310's: such as model 310, 310C, 310F or later called FET, 310TEL, 310Jensen (sold only by Sherman Jensen/Stanley Tools mailorder), 310 IBM as issued by IBM field svcs to every certified IBM mainframe engineer, which is why every known IBM service manual pictures the TTT 310 which has modified DCV ranges to comply with the TTL logic levels of that time. 310Bell for telephony work, and many I'm not aware of, as my engfiles here show at least 250 additional types of 310's that Triplett made for various special corporations for special applications.

And last but not least, the 1970's thru the closing in '07 Model seris "60's" analog VOM's, which were all developed to conform to the new ANSI/MSHA mines antispark/detonation safety protocols; they include but are not limited to: model 60, 60A, 60ES, 60D, 60DC, 60NA, 60AC and last but not least (my very own favorite in this 60's series), their model 64FET....which I just yesterday sent the new/nos manul to one of our new ARF members at no charge so he could actually figure out and use his model 64FET. All of these are rated for up to a 6ft fall to a hard floor w/o damages....but don't count on it...!!!!!

If anyone of you needs further specs or marketing or eng info on any of them, please ask me as I have a decent knowledge of it, and I also have the complete original sets of all the engineering files on all of them here in Oswego NY 13126 at the State University.

Mr. Douglas, I will be PM'ing to you my Cell phone number for when you're ready to call to arrange to get the information you will need for your next book.
Fred


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Nov Wed 23, 2011 8:24 pm 
Member
User avatar

Joined: May Wed 18, 2011 2:40 am
Posts: 1382
Location: Littleton, MA
MarkPalmer wrote:
I think the 30 volt battery thing, even though easy deal with, has shied me away from the older TTT's.

I bought an Eveready 413 30 volt battery for my 630-PL from Battery Mart: http://www.batterymart.com/p-eveready-4 ... ttery.html, along with an Eveready 412 22 1/2 volt battery for my URM-105C. A little pricey, but I figure it should last quite a few years before needing replacement.

Looking at Battery Mart's site again, I see that they now warn "Limited Quantities Available" on the Eveready 413 and 412. Maybe it's gone out of production? Perhaps the Chinese will revive it as they have others such as the No. 6 dry cell.

Best regards,
-Steve

_________________
Steve Byan http://www.byan-roper.org/steve/steve-at-play/


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Nov Wed 23, 2011 8:25 pm 
Member
User avatar

Joined: May Wed 18, 2011 2:40 am
Posts: 1382
Location: Littleton, MA
Dean Huster wrote:
notice that the Triplett has a switch setting for the 10A current range while the Simpson has you move the banana plugs to special 10A jacks. The 10A shunt is directly across those 10A jacks while the contact within the function/range switch of the Triplett is part of the 10A circuit. If you accidentally overload the meter on the 10A range, you can blow the contact on the switch to smithereens.


Dean, thanks for the warning.

Best regards,
-Steve

_________________
Steve Byan http://www.byan-roper.org/steve/steve-at-play/


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Nov Wed 23, 2011 8:30 pm 
Member
User avatar

Joined: May Wed 18, 2011 2:40 am
Posts: 1382
Location: Littleton, MA
Fred Scoles wrote:
Next comes the model 630-L, which was the very first VOM having the "sexy-looking" big clear lucite window, with the large red "luscious" (as another ARFer wrote just last week) knob, and the "L" featured a "low power OHms" scales (not enough power to trigger forward biasing in either a Ge or Si chip) w/o any active components inside....quite a feat at the time...but to do that they had its Ohms scales running backwards, which drives most of us nuts to use this model.


Hi Fred,

Thanks for the excellent summary of the Triplett 630 series lineup. The 630-L sounds very interesting, I hadn't come across this model before. Thanks!

Best regards,
-Steve

_________________
Steve Byan http://www.byan-roper.org/steve/steve-at-play/


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Oct Sat 13, 2012 9:40 am 
New Member

Joined: Oct Sat 13, 2012 8:10 am
Posts: 1
Mr. Fred Scoles,
I see that in the past you had written an article regarding the Triplett 631 and it's no longer available 22.5 volt batteries. I have recently acquired a 631 and would appreciate any information you may have regarding substitution of the Burgess No. XX15 battery.
Thanks for you help.
John


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Oct Mon 15, 2012 5:15 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 1541
Location: Oswego, NY, USA
John, PM to me your email address, so I can email to you the Triplett 631 battery article to you as an MS Word attachment. The article was on triplett.com site from '03 thru '07, when Jewell web-management decided to remove it and a number of older articles & references. My original version (on MS Word '97) also didn't display the photos reliably with newer versions of MS Office software, so it has been upgraded and should work on your computer.

There have also been various other battery replacement/upgrade plans for the TTT631 written by others, in varying degrees of usefulness. Back in '03 when I wrote my version, there were a few battery replacement plans previously on the web for the 631 that I considered not good & not well thought out, which provided the incentive to write a better article, which was approved and edited by the Triplett web designer in Bluffton for their site.


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Oct Mon 07, 2013 6:49 pm 
Member
User avatar

Joined: May Wed 18, 2011 2:40 am
Posts: 1382
Location: Littleton, MA
Fred Scoles wrote:
Next in line in the TTT 630's is model 630-M, which went thru only 2 production runs, and a total of six of them were ever made and according to Mr. Ropp Triplett (pres when I was growing up), only two of them got out the door to a distributor. Just last year on Ebay I bought the only surviving example of an "M" and it is in perfect, original condition....and it has no known $$$$ value assigned to it as I have the only known example in my collection. Simpson never ever had anything like it. My "M"'s native mvt is 1ua fs for 1 million Ohms per volt DCV, and 500,000 opv with the slider kicked to the Right (it looks identical to a 630-na or ns on the outside); inside it's totally different though simply because at that high sensitivity they could not use the regular bakelite resistor holder turrest because the bakelite attracted too much static and/or summer humity, so it as a special circuit board and white nylong sleeves around its panel jacks. I snagged it last yr off Ebay simply because I was the only soul on earth who even knew what it was.

Fred, are you sure about there only being six 630-M's produced? I just picked one up from Craigslist, and one sold on eBay recently:
http://www.ebay.com/itm/ws/eBayISAPI.dl ... 1134328536

The instruction manuals seem to be pretty plentiful on eBay, too.

_________________
Steve Byan http://www.byan-roper.org/steve/steve-at-play/


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Oct Mon 07, 2013 8:35 pm 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 1541
Location: Oswego, NY, USA
I don't know how many M's were made or sent to distributors, but far fewer were made than any other model VOM. Workers at the plant I had talked with definitely didn't enjoy building or calibrating them because of their sensitivity and susceptibility to circuit board contamination, and the difficulty selling-distributing them. They were roughly twice the price of the NS, part of it due to the labor and time to calibrate. I don't know why there seem to be stockpiles of the M manuals; I saw several boxfuls of the new manuals in the warehouse just after the plant shut down; but for whatever reason, none of the M engineering files survived or could be found. At one time, Cenco and SargentWelch offered Triplett 630-M and 601, 602, & 603 (transistorized VOM's) to schools, but few sold and much of their stock was later landfilled.


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Jul Mon 07, 2014 4:33 pm 
Member
User avatar

Joined: Apr Sun 10, 2011 2:53 am
Posts: 53
Location: Corona, Calif
Thank you all for this thread. It's been very imformative and useful.

I just picked up an "M" on eBay (or what purports to be one). Mine's in rougher shape. When it arrives, I'll take photos in case anyone's interested.

_________________
- James (KJ6PJB)
www.jollinger.com/radio/


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Jul Mon 07, 2014 5:00 pm 
Member
User avatar

Joined: May Wed 18, 2011 2:40 am
Posts: 1382
Location: Littleton, MA
I'm in the process of scanning the manual for the 630-M. I'll put it up for download and let everyone here know the URL when it's ready.

_________________
Steve Byan http://www.byan-roper.org/steve/steve-at-play/


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Jul Wed 09, 2014 3:40 am 
Member

Joined: Jan Thu 01, 1970 1:00 am
Posts: 1541
Location: Oswego, NY, USA
James, I think that 630-M went through only one "Type 1" major design, so all M's should have the thick fiberglassed flat circuit board construction; not the normal 630 series black bakelite round resistor turret. Will yours come with the standard black-bakelite case bottom, or the optional clear-acrylic bottom? For whatever reason, none of my archive papers include the 630-M engineering or marketing files, so I don't know the official reasons they went with the flat component board design instead of the bakelite rotary turret the other 630's used.


Top
 Profile  
 
 Post subject: Re: TTT630PLK vs. Simpson 260-4 thru 7P VOM designs similari
PostPosted: Jul Wed 09, 2014 6:15 am 
Member
User avatar

Joined: May Wed 18, 2011 2:40 am
Posts: 1382
Location: Littleton, MA
I first heard about the Triplett 630-M in the post above in this thread from Fred Scoles.

I found one locally that has an unbalanced meter movement. It appears to be in calibration when sitting horizontally on the workbench, but the zero changes if I stand it vertically.

Image
(Full size image here.)
I haven't torn into it yet, but I did open it up and take a photo of the internals. Perhaps they had to go with a glass-epoxy circuit board to get the leakage currents low enough for the 1 µA (!) meter movement.

Fred was kind enough to send me a manual for the 630-M, which I have scanned and put up for download in my Liberated Manuals section.

http://www.byan-roper.org/steve/manuals ... _630-M.pdf

_________________
Steve Byan http://www.byan-roper.org/steve/steve-at-play/


Top
 Profile  
 
Post New Topic Post Reply  [ 27 posts ]  Go to page 1, 2  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: Yahoo [Bot] and 7 guests



Search for:
Jump to:  




















Privacy Policy :: Powered by phpBB