PEC volume pots Part #.

John Lacey · Post by **John Lacey** » 19 Nov 2002 4:19 pm

I checked with B&E Electronics in Calgary who carry these inexpensive 500k. ohm volume pots and this is the info they gave me.
Part #KU5041S28
RV4NAYSD504AF2 (model #?)
B&E Industrial Electronics
444 Manitou Rd. S.E.
Calgary, Alberta, Canada
1-403-243-7211

Donny Hinson · Post by **Donny Hinson** » 19 Nov 2002 5:40 pm

I've used those (RV4-Mil-Spec) pots, but they have a thinner resistance element, and do not have the service life of the thick ("hot-molded") element in the JAIN200-Mil-Spec series. The RV4's will work in a pinch, but I only got 4-6 months use out of them, compared to 3-5 years for the JAIN200's.

Jay Ganz · Post by **Jay Ganz** » 20 Nov 2002 7:03 am

I may be wrong but according to
everything I've seen on various sites,
if the "military #" (which is the RV4
numbers) has an A after the 504, then
it's actually linear taper. Now....
if the old Allen Bradley number (which are
the JA1N numbers) have an A after that 504,
then those are audio taper. As
near as I could decipher, the PEC # that
is audio taper is the KAR64. The Clarostats
can have the "Allen Bradley" number on it,
or their own #, which would be a 53C1Z.
Then again, I may not know what the heck
I'm talking about!

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Steelin' Video * * * <a href=http://home.hvc.rr.com/jsganz/Steelin'.mpg> Clip-1</a>* * * *<a href=http://home.hvc.rr.com/jsganz/Wraparound.mpg> Clip-2</a>

John Lacey · Post by **John Lacey** » 20 Nov 2002 7:21 am

Donny, I'm not really sure about any of that. Maybe I'll contact the distributor in Calgary and ask him on the life expectancy of that part. I do know that Paul Franklin Sr. is stocking them as I found out my info from Greg Derksen, who found out from Paul. I think that there are 2 variables, the shaft lenght and the taper. I'll will try to clear this up soon. PS, Greg's had his in for at least a year and has had no problems with it.

Donny Hinson · Post by **Donny Hinson** » 20 Nov 2002 8:58 am

The pots that I use are JAIN200P504AA, but I'm told the AU suffix is usable, as well. I believe one is a log taper, and the other is a reverse-log taper. Although the "log" taper is not exactly the same as an "audio" taper, they are close enough to be interchangable...or so I'm told. (I find the "linear" taper pots to be totally unusable.) I'll get the Mil-Specs on both to see what the differences are.

(When looking for a substitute, look for one with a life-expectancy of at least 250,000 cycles. The old A/B units were rated at 750,000 cycles.) [This message was edited by Donny Hinson on 20 November 2002 at 09:01 AM.]

Donny Hinson · Post by **Donny Hinson** » 21 Nov 2002 5:04 pm

Well, you learn something every day! I did some further checking on the pots today. Back when I used them, the RV4 pots had a deposited (sprayed) phenolic resistance element. The newer RV4 pots have a "conductive plastic" resistance element. I don't know when this change occurred, but they may well have a lot better life than they used too. Both are rated 2 watts, with a max voltage of 500. Though the RV4 is cataloged as a "direct replacement", the company (Clarostat) still produces both designs. There must be some significant difference, but I haven't found out yet what it is. I have been unable to find the life expectancy of the RV4 design, but I did find out that the life expectancy of the JA1N (type "J") dropped, at some point, to 500,000 cycles. I don't know if this was a change in the mil-spec, or a change in the manufacturer's design. Luckily, I bought a half-dozen of the Allen-Bradley pots (reputed to be the best) 30 years ago...when they were only $4.00 each.

Also, as I mentioned some time ago, a company called Piher Electronics now manufactures pots that have a life expectancy of 1,000,000 cycles. If they could be had in the proper design, and if they're rugged enough, these would certainly corner the market.

I'll continue my research.

Ken Fox · Post by **Ken Fox** » 25 Nov 2002 7:10 am

Here are some specs on RV4 pots, they are linear taper and lower life expectasncy that the Clarostat pots that we normally use:

MIL Style RV4 Potentiometer

Features:

• Conductive Plastic or Hot Molded Carbon element

• Gold-plated terminals

• Stainless-steel shaft and housing

• Quality meeting or exceeding MIL-R-94 - QPL listed

• Commercial equivalents available

• For dual units, see Mil Style 2RV7

Options:

• Custom shafts and bushings
• Special tapers
• Fourth (center) terminal
• High life
• Attached switch

Electrical Specifications

Resistance Range
50 ohms to 5 Megohms - Linear Taper
150 ohms to 1 Megohms - Logarithmic Taper

Resistance Tolerance
+/-10% or +/-20%

Resistance Taper
Linear, Logarithmic, Reverse Logarithmic;
other tapers by special order

Power Rating
2 Watts @ 70°C; Derate to 0 Watt @ 120°C

Insulation Resistance
Dry: 10K Megohm; Wet 100K Megohm

Dielectric Strength
Sea Level - 900 V RMS

Operating Voltage
500 V, subject to power rating

Mechanical Specifications

Mechanical Rotation
314°

Torque
Operating - 1 oz. in. to 6 oz. in.

Rotational Life
25,000 cycles

Environmental Specifications

Operating
Temperature
-65°C to +125°C

Resistance to
Soldering Heat
350°C for 5 seconds

Humidity Range
per MIL-R-94

Vibration Range
per MIL-R-94

Shock Resistance
per MIL-R-94

Load Life
1,000 hrs. @ 70°C