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 Post subject: Triplett 850: A VTVM or VOM?
PostPosted: May Mon 03, 2004 11:27 pm 
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Location: Riverside, CA
I've seen these come up on eBay from time to time advertised as either a VTVM or a VOM. Does anyone know which one it is? Anyone have one and if so, how do you like it?<P>Regards,<BR>Geoff<P>------------------<BR>


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 Post subject: Triplett 850: A VTVM or VOM?
PostPosted: May Mon 03, 2004 11:44 pm 
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If it has a power cord, it's a VTVM. If not, it's a VOM.<P>The W7FG manuals site lists it as a VOM, along with the 630, which I know is a VOM.<P>------------------<BR>73 de Leigh W3NLB | | Leigh@AtwaterKent.Info<BR><A HREF="http://www.AtwaterKent.info" TARGET=_blank>http://www.AtwaterKent.info</A> | | <A HREF="http://www.Synchrophase.info" TARGET=_blank>http://www.Synchrophase.info</A>


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 Post subject: Triplett 850: A VTVM or VOM?
PostPosted: May Tue 04, 2004 2:18 am 
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Location: Wichita KS USA
On the lower part of the meter face, it is identified as an "Electronic Volt-Ohmmeter". It is a VTVM, uses two tubes and no battery. Mine works fine. Bought it mostly because of meter face size, I like large meter faces, Hickok 209, Radio City Products 665, etc.<P>------------------<BR>


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 Post subject: Triplett 850: A VTVM or VOM?
PostPosted: May Mon 02, 2005 10:00 pm 
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Location: Oswego, NY, USA
Based on the circuit diagram and components used, the Triplett model 850 and the RCA Senior VoltOhmyst (Rev. A) VTVM's are almost identical, except the RCA has an adjustable pf capacitor for the higher frequencies. I don't know why Triplett called theirs an "Electronic Volt Ohmmeter", instead of a VTVM. Both of them have the same problem with the Ohmmeter ranges; the ohmmeter multiplier resistors are 5 percent carbon comps (potentially inaccurate); possibly because they knew most people use the ohmmeter function infrequently. <P>------------------<BR>


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 Post subject: Triplett 850: A VTVM or VOM?
PostPosted: May Mon 02, 2005 10:50 pm 
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Location: St. Paul, Minnesota
Originally posted by Fred Scoles:<BR><B>the ohmmeter multiplier resistors are 5 percent carbon comps (potentially inaccurate); <BR></B><P>They're pretty nice, as far as VTVM's go, mainly because of the large meter. Huge PITA to restore though, because of the reason above. There are some carbon comp's in other circuit segments where you'd hope not to see such things, and many of them are located on switches or other tight spots. They're good nostalgia pieces, but if you're after much accuracy, you'll have to invest a lot of work to get there. If you end up getting one, I have a scanned copy of the manual I can send.<P><BR>------------------<BR>


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 Post subject: Triplett 850: A VTVM or VOM?
PostPosted: May Wed 04, 2005 5:19 am 
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Location: Winnipeg, Manitoba, CANADA
Leigh, I'm sure you must own at least one battery VTVM. I know I do; a Triplett 631. Plus there is a Precision 78, and a Simpson I know I have somewhere. But my Triplett 850 is a VTVM, and it works fine. <P>------------------<BR>"You can lead a horticulture, but you can't make her think."


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 Post subject: Re: Triplett 850: A VTVM or VOM?
PostPosted: Apr Thu 08, 2010 6:13 pm 
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Joined: Dec Sat 02, 2006 5:27 pm
Posts: 117
Location: New York
Erik K wrote:
Originally posted by Fred Scoles:<BR><B>the ohmmeter multiplier resistors are 5 percent carbon comps (potentially inaccurate); <BR></B><P>They're pretty nice, as far as VTVM's go, mainly because of the large meter. Huge PITA to restore though, because of the reason above. There are some carbon comp's in other circuit segments where you'd hope not to see such things, and many of them are located on switches or other tight spots. They're good nostalgia pieces, but if you're after much accuracy, you'll have to invest a lot of work to get there. If you end up getting one, I have a scanned copy of the manual I can send.<P><BR>------------------<BR>


Hi Erik:

I just acquired a Simpson VTVM model 850. It's not well - it would be greatly appreciated if you could email your scanned manual.

Best regards,

-TommyR


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 Post subject:
PostPosted: Apr Thu 08, 2010 11:44 pm 
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Location: Oswego, NY, USA
TommyR,


Simpson 850??....if you're referring to a Triplett 850, I have extra NOS manuals for it, should I mail one to you? The TTT850 scanned manuals on the internet that I've seen aren't that great. The Triplett 850 was possibly indended as the replacement for the 650, based on the marked-up manuals.

also since the RCA WV98A is identical to the TTT850, the RCA manual on bama-edebris has some good extra sections on how to fine calibrate the tester.

Fred


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 Post subject: Re: Triplett 850: A VTVM or VOM?
PostPosted: Apr Fri 09, 2010 4:07 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 1717
Location: Chillicothe, Ohio 45601
Fred Scoles wrote:
Both of them have the same problem with the Ohmmeter ranges; the ohmmeter multiplier resistors are 5 percent carbon comps (potentially inaccurate); possibly because they knew most people use the ohmmeter function infrequently. <P>------------------<BR>


There must have been a lot of change between the WV-98A and WV-98C because most of the resistors in mine are 1% carbon film.

Rod


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 Post subject:
PostPosted: Apr Fri 09, 2010 1:56 pm 
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Joined: Dec Sat 02, 2006 5:27 pm
Posts: 117
Location: New York
Fred Scoles wrote:
TommyR,


Simpson 850??....if you're referring to a Triplett 850, I have extra NOS manuals for it, should I mail one to you? The TTT850 scanned manuals on the internet that I've seen aren't that great. The Triplett 850 was possibly indended as the replacement for the 650, based on the marked-up manuals.

also since the RCA WV98A is identical to the TTT850, the RCA manual on bama-edebris has some good extra sections on how to fine calibrate the tester.

Fred


Hi Fred:

I was confused. It is a Triplett.


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