Sprague 6x39k... what is it?

[miloc9]

I am trying to repair a non-working Sears Fence Charger model 436.77730, 110 vac unit. It contains a device built by Sprague (marked "Sprague 6X39K) that's orange in color, about 3/4" by 3/8" rectangular shape and has 2 leads coming out of the edge marked "1" and "2". It looks like a ceramic or film capacitor but measures about 256k ohms (checked with a Fluke 77 meter) and passes about 34 vdc thru it. Can anyone verify if this device is in fact a resistor or if it's a capacitor that's developed a resistance problem. I've checked many Sprague sites as well as the Sears website and can't find any information on it at all. I'd appreciate any helpful info or tips.

[Chris Smith]

From what you describe, and all of my military hardware hacking and repairs, I would say it was a Cap. The orange, in color, and the fact that orange also represents thousand plus the 39k, and a few other hints, Id say CAP? Value is 39,000 pf. [too small to be uf] @ 3 or 6 hundred volts? <p>6x, cant remember exactly? but Id say it in units of 50 or 100 volt per number x range or meaning 6x50=300 volts or 6x100=600 volts. <p>Dean Huster might know more on that one? He is listed under a Email on his post. <p>My work involved repairing old military Scopes, which all had Sprage parts in them, but they had paint color dots to mark their values like color bands on resistors.<p>[ May 11, 2002: Message edited by: Chris Smith ]</p>

[josmith]

It could be a surpressor with both a resistor and cap in it.

[russlk]

Sprague made resistors as well as capacitors. I was Hybrid Product Engineer for Sprague at one time, but I do not recognize that part number. I suspect it is a resistor made up of 6, 39k sections in series (234K) and is used to limit the current at the output.

[Dean Huster]

I would agree with Russ. Is it a device that has possibly had five leads between the two existing leads cut off for this application? 6x39K sounds like a resistor pack, similar to those used for pull-up or termination applications, except that this one has all resistors connected in series. In this case, maybe this device was used because it gave them their resistance value with a good voltage rating for use in the fence charger.<p>I would doubt that it's a capacitor, especially if you've measured a resistance value across the pins, with one end disconnected from the circuit, I would assume. A "39" value for a cap is pretty rare as they tend to use just the 20% EIA values (10, 15, 22, 33, 47, 68) even if the tolerance is as tight as 1%. If it happened to be a capacitor, it would definitely be bad with a resistance measurement like that.<p>Dean<p>[ May 13, 2002: Message edited by: Dean Huster ]</p>

[Edd]

miloc9.........hmmmm sounds like a former covert CIA operatives code name.
On your 6x39k identity, I looked at all of my film resistor arrays and out of ~500.. all were CTS or DALE units. Looks like the ones I remembered are still on some old pcb's....Seems like Collins Radio bds. I wanted to confirm their numbering system. They were the typical bright orange that u still see today on Spragues round monolithic ceramic units.The length and width are your dimensions and the THICKNESS is 1/8 in and is packaged as a SIP layout on its leads. As you were viewing the long dimension of the unit, u cud see minor aberrations of the case where the indiv cells were. With all 39k film on substrate units, one version had a common to one leg of all the res units but yours has to be the other version that has all units daisy-chained with 39k indiv tap offs.
I assume that your res readings were taken out of circuit...so u cud confirm the connections were made to the longitudinal end leads and 5 were cut off in the center area.....if they didn't encapsulate/pot over with a conformal coating on the lead edge.
Looks like Sears can give great logistic support on Web site...you can get a 3AG fuse to replace that Camel tin foil slug that Gomer put in there, or the fuseholder cap that Junior twisted off with pliers, and then u can get a new NE51 neon glow lamp that indicates HV pulsing...or if brite, theres a weed across the fence.....or usually a young calf spread eagled across the fence. Calling up Sears.com for further data, all we then get is a pic of the unit.That lets us zero in to dating as to its being a definite post Neanderthal-pre Cro-magnon vintage of unit. Sears National Electronics/Small Appliance/ Electrical tools service/refurbishing Center is within miles of me but even they didn't have data or a fiche on this unit....usually their coding tells who made it for them...no luck. Probably there's the <No user serviceable parts inside> label on the unit.
They want u to buy an inferior grade new one ?
With relatives in ranching/farming , I've always been their go to guy. I was building units back in the '50s using model T coils and car batts. Then in the mid 60's started making units with a relaxation neon osc ckt or npn/pnp bipolars configured as an "ersatz UJT" gate spiking a 300V SCR which was driving an auto ignition coil ...excellent performance! Forward ur E-mail and I shud be able to assist you in troubleshooting via that mode in order to get ur"heirloom" going again..
Tnx & 73's de Edd