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 Post subject: Bad Simpson 260
PostPosted: Jul Thu 25, 2002 6:46 pm 
I just got an e-bay Simpson 260. I can't figure out which series. It uses 4AA and a D cell. Voltage readings are fine, but resistance measurements are all messed up. Can't zero it on the high resistance scale (pins to the right) and on the two lower scales any resistor reads around the same physical spot on the meter, around 1.4. Same approximate spot regardless of the value of the test resistor and for either range setting.<P>I assume I have to get in behind the fixed carousel that holds the switchable resistors in order to test and replace whichever resistors are toast. What is the process for getting this thing apart?<P>I realize the disassembly procedure probably varies according to which series it is, but I can't find any indication of which it is.<P>Larry<BR><P>------------------<BR>


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 Post subject: Bad Simpson 260
PostPosted: Jul Fri 26, 2002 1:34 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 563
Location: South Louisiana
HI Larry,<P> I have a 260 which also uses 4 AA & one D cell it's a series 3. Series 3 is printed on dial face below Simpson 260 & also inside between the cal pots on the board it's marked series 3. With the back cover removed on mine, most of the resistors are exposed on the board & can be tested without disconnecting or in some cases rotating the selector switch & removing batteries will allow checking the resistors. Although we may not have the same Simpson, this might help determine what series you have.<P>------------------<BR> regards,<BR> Bobby


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 Post subject: Bad Simpson 260
PostPosted: Jul Fri 26, 2002 2:56 am 
No luck. Theres no indication of any series on the faceplate or on the face of the meter.<P>The resistors are arranged in a sunken Manhattan style in two concentric semi-circles of oval shaped holes in the plastic rear housing. Only one lead is accessible at the top of each resistor. This housing is held on by two long screws, but some of the leads coming off of it to the jacks (the amps jacks in particular) are very short, so would have to be unsoldered to remove it. Actually now that you mention it, I can't see any adjustment pots, either to the rear of this housing or peeking in from the sides.<P>I've just posted a shot of the resistor array it in alt.binaries.pictures.radio<P>------------------<BR>


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 Post subject: Bad Simpson 260
PostPosted: Jul Fri 26, 2002 3:36 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 11474
Location: Valley City ND USA
I have one of those too OZ. I can only presume they were first of the line as it has no series no..<P>------------------<BR>terry h


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 Post subject: Bad Simpson 260
PostPosted: Jul Fri 26, 2002 8:54 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 7778
Location: Beaver Falls, PA. USA
Hi, OZ... I have one of those early Simpson 260s (and the manual!). If it will help, I can snail-mail you a copy of the manual. Most likely, R16 (11.5 ohms) is the culprit; it is number 6 on the outer circle of resistors counting from the lower left in a clockwise direction. If the previous owner applied voltage with the meter on the RX1 scale, this resistor probably burned out. The other resistors in the ohms circuit are in this same outer circle; #2 is 117.7k, #3 is 21.85k, #4 is 110 ohms, and #5 is 1138 ohms. I hope this is some help.<P>Tim<P>------------------<BR>


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 Post subject: Bad Simpson 260
PostPosted: Jul Fri 26, 2002 4:15 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 2846
Location: Warwick,RI
Oz,I have bought at least 25 pieces of test gear on eBay(a lot is still awaiting restoration)and the ones that I have checked or restored up to this point all have things wrong with them not mentioned in the eBay ads.Most eBay sellers don't know much of anything about what they are selling in the techical vein.I believe every online auction instrument purchase must be approached with the assumption that it needs restoration before it is likely to be really useable.We aren't buying **just* an instrument,but rather an instrunment plus a bunch of problems requiring solving.I wouldn't be concerned with troubleshooting the specific problem involved;I would completely (or as much as necesary)diassemble and test **everything** and clean and lubricate *everything* that can be cleaned and lubed.All this older gear needs a thorough overhaul,and in that process,of course,you will isolate your particular problem.Looks like Tim has the information you need to proceed.You might know all this,of course....but again,I would adopt a resoration,not repair mentality on this baby.<BR>Malcolm<P>------------------<BR>


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 Post subject: Bad Simpson 260
PostPosted: Jul Fri 26, 2002 5:26 pm 
Oz wrote:
<font>quote:</font><HR>Originally posted by Tim Tress:<BR><B>Hi, OZ... I have one of those early Simpson 260s (and the manual!). If it will help, I can snail-mail you a copy of the manual. (...)<BR> <BR>Tim<BR></B><HR>
<P><BR>Tim, thanks for the offer. My address is<P>Larry Ozarow<BR>28 Sunderland Drive<BR>Morristown, NJ 07960<P><BR>The seller didn't represent it as working. You know, the usual "I don't know how to work these things," so I expected it would need something. I'm a little disappointed at my not being able to figure out how to open up the darn thing, but it's all part of learning.<BR><P>------------------<BR>


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 Post subject: Bad Simpson 260
PostPosted: Jul Fri 26, 2002 6:47 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 7778
Location: Beaver Falls, PA. USA
I'll get the manual copied for you. It doesn't have any disassembly instructions, but it does have a schematic, theory of operation, parts list and layout.<P>Tim<P>------------------<BR>


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 Post subject: Bad Simpson 260
PostPosted: Jul Fri 26, 2002 11:15 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 4175
Location: Charleston, W.Va.
Malcolm, I could not agree more on your general comments about Ebay test equipment. I have put so many hours of time and effort into RCA test equipment that I have bought on Ebay over the last couple of years, that I think I have reached the point where I know more about repairing this equipment than I do about repairing the actual radios and TVs it was designed for!<P>OZ, I don't know much about the Simpson 260, but I have worked on a lot of VTVM's, mostly RCA VoltOhmysts. The info Tim is sending you will definitely fix you up. In my experience, these precision resistors will seldom change value, but they can be damaged by application of voltage as Tim mentioned, unless they are protected by internal fuses as RCA did. I assume you have already checked the obvious: good batteries and battery connections. Your OHMS potentiometer can also be at fault--once you obtain its value you can check it out. You might also be interested in the following, which I am quoting from original RCA trouble-shooting service info:<P>PROBLEM: Resistance readings inaccurate on some or all "ohms" ranges; works normally on ac and dc voltage measurements.<P>1. One or more resistors in network around switch S1 have changed value.<BR>2. Excessive leakage in "ohms" circuit. Check switch wafers on S1 for dirt or damage.<BR>3. Poor contact from ground jack to ground bus on chassis.<BR>4. Shorted wiring in resistor network around S1.<BR>5. Faulty or high-resistance connections in "ohms" circuit.<P>Hope this helps, <P>------------------<BR>Poston


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 Post subject: Bad Simpson 260
PostPosted: Jul Sat 27, 2002 10:53 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 512
Location: Columbia, NJ USA
Larry <P>The key to buying Simpson 260's is to buy cheap and send it to Simpson for repairs. You get a Simpson 260 back that is like new. <BR>The Company still supports them with service. Do Not use Hosica Labs In NJ. They will charge you $ 70 plus shipping with NO guarantee. If it fails they will tell you that you abused it. Been there, done that. I have my original Simpson 260, I bought in 1955 when I came out of the service and it has never failed me yet and they had the nerve to tell me that I abused the one I bought on E-Bay and had them service and calibrate. It failed exactly the same way, AC voltages became erratic. When I call them after the 2nd failure, they told me they were waiting for a schematic. My question at that time was how did you fix it the first time, their answer, the technician that fix it the first time was more knowledgeable of the unit. I told them to keep the meter rather than pay the bill twice with no guarantee.<P>Ralph<BR><P>------------------<BR>


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 Post subject: Bad Simpson 260
PostPosted: Jul Sat 27, 2002 10:59 pm 
Thanks all for your guidance, and to Tim in advance for the manual copy.<P>Poston, apropos of your comments, Mr. Fedex just dropped of an E-bay Voltohmyst WV-98c.<BR>After I remove a layer of tape goop and unsolder the dead but fortunately not leaky D cell, I hope not to need help on this one!<P>I was at the New Jersey ARC swap meet earlier today, and I need something to take my mind off of a couple of goodies I couldn't justify buying.<P>Larry<BR><P>------------------<BR>


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 Post subject: Bad Simpson 260
PostPosted: Jul Sun 28, 2002 11:53 pm 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 4175
Location: Charleston, W.Va.
Larry,<BR>You will be glad you bought your WV-98C VoltOhmyst. It is one fine instrument, and that super huge RCA meter dial makes it a pleasure to use.<BR>I have worked on several of these; in fact just did one earlier this month. I have been lucky, and never found anything really seriously wrong with any that I have serviced. One thing you should definitely do up front is replace that little selenium rectifier and the 10uF/200V electrolytic filter capacitor. This is an easy fix--plenty of room in that area of the chassis, and does not require any disassembly other than removing the chassis from the case. Quite often the selenium rectifier and filter capacitors in these will still be good, especially if it is a later model, but I have found from experience that sooner or later they will give you problems. If you need any help on this one, let us know. <P>------------------<BR>Poston


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 Post subject: Bad Simpson 260
PostPosted: Jul Tue 30, 2002 11:54 pm 
Gotta put in a word for Tripplet in this. My boss at my first job loved Simpson,and I loved Triplett...much dissention over this..even though it's obvious the Triplett scales make more sense. Both of us blew low ohms on occasion,but my Tripplet had a VTVM built in..it used a 1R5,and the ohms batteries;it worked great. When the time came to equip new servicemen,he got them Simpsons(it's better,that's why)and they all looked at my Tripplet with envy. Don't know if Simpson made a VTVM in the 260 case,but triplett made one in the 630. I still have that Triplett,and it still works well after 40 years,but I respect guys that like simpsons(just because....)...and then,there is the Weston contingent...<P>------------------<BR>


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 Post subject: Bad Simpson 260
PostPosted: Jul Wed 31, 2002 2:04 am 
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Joined: Jan Thu 01, 1970 1:00 am
Posts: 1156
Location: Las Vegas, NV, USA 89052
"Don't know if Simpson made a VTVM in a 260 case...."<P><BR> My Simpson 303 VTVM (except for four screen covered ventilation holes) is in the same case as my Simpson 260 VOM. <P>Greg<P>------------------<BR>


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