Old Wire Wound Resistors - Page 1
Forum section: electronics / beginners

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: March 23, 2023, 12:01:27 pm
content: Hope this is the appropriate spot to postI recently acquired a bunch of old wire wound resistors New Old Stock402.2 K 1/10 %NAT. RES. Pearl River New YorkThey are within specs still Measure 402.2 K on my Biddle Bridge and all are very close in values on my HP 3456About 1.95 Henries on my GenradWere these used in any equipment that anyone knows of?

author: CaptDon
author_rank: Super Contributor
timestamp: March 24, 2023, 01:59:18 pm
content: I can't imagine the value of a high ohmage resistor with that much inductance.

author: CaptDon
author_rank: Super Contributor
timestamp: March 25, 2023, 01:03:01 am
content: It kind of occurred to me at 1.95 Henries that is a lot of wire. I see the 1/10th % rating on the resistance. I should think that would vary drastically with temperature change? I guess the wire could be a blend of different metals but I am not sure zero temperature drift can be obtained, at least within .1% across say 0c to 70c? Just pondering how this thing was used? Cheers mate, hope someone can chime in on its intended use.

author: amyk
author_rank: Super Contributor
timestamp: March 25, 2023, 01:35:45 am
content: I suspect they would've been used in vacuum tube circuits.

author: Kim Christensen
author_rank: Super Contributor
timestamp: March 25, 2023, 02:27:01 am
content: Quote from: Wallace Gasiewicz on March 23, 2023, 12:01:27 pmAre you sure that's an accurate measurement? Doesn't sound right to me at all.

author: vk6zgo
author_rank: Super Contributor
timestamp: March 25, 2023, 03:56:36 am
content: Quote from: amyk on March 25, 2023, 01:35:45 amNah, resistances of such values would normally be the province of carbon composition resistors in the tube daysMost of the wirewounds used in tube gear would "top out" at a couple of hundred ohms.The resistors concerned may have been used in DC bridges or something of that nature, where the inductance wouldn't have mattered.

author: Jwillis
author_rank: Super Contributor
timestamp: March 25, 2023, 04:37:25 am
content: Wire wound resistors are for low frequencies. Parasitic inductance increases with frequency. Recheck your measuring frequency. Best measuring frequency is around 100- 120Hz buy usually no more than 1 KHz.I pulled out some old Soviet era wire wound resistors and measured the inductance of those . I pretty much ended up with the same results you did with a 300K resistor rolling in at around 2H at 100Hz then dropped off at 1K to around 400uH then again rising to 150mH at 100KHz. I suspect as the frequency increases to the Self Resonating Frequency the inductance increases then drops suddenly at the SRF. Then increases again as frequency continues to increase. Just what I observed with a very basic experiment.Best use is DC applications.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: March 25, 2023, 08:43:29 pm
content: The resistance on these is measured on several different meters and is quite accurate on all meters, including a DC Wheatstone Bridge. 402.2 KThe only thing I have that can measure the inductance is a Genrad 1650 LCR Bridge and gives the near 2 Henry reading, Genrad 1650 measures at ONE KHzAll my other instruments will not measure this high in inductance and read over full scale. I remeasured several times.I also thought this reading was unusual.I guess I could test at lower freq putting external signal into my GR 1650It looks like wire wound on a hollow bobbin, you can see thru the center. and the leads are soldered to small terminals on the bobbin. I did not take one apart.About 2 cm in length, one cm dia.I cannot figure out what it could have been used for either. I just picked them up because of the 1/10 % rating, to have something for a quick resistance check.By the way it actually sez 1/10 % not .1%Maybe Audio filter? But it is a resistor primarily since the inductance is not listed on the paper cover.I also thought maybe a resistive divider?? In a DC test instrument, like a bridge. But with that value?If anyone wants one or more . the shipping cost would be the biggest part of the bill. PM.Thanks for the responses, it is absolutely amazing that all the responses are pertinent. I just thought the resistors were interesting.

author: Jwillis
author_rank: Super Contributor
timestamp: March 25, 2023, 11:40:06 pm
content: Quote from: Wallace Gasiewicz on March 25, 2023, 08:43:29 pmThey're old vintage power resistors. Wire is wound on a ceramic tube then coated with ceramic glaze . Similar to below.They were used in many things. Radio, Television, Audio. Think I had a frequency generator that had one. Used a lot in tube equipment. They didn't worry much about parasitics in that kind of stuff back then.

author: vk6zgo
author_rank: Super Contributor
timestamp: March 26, 2023, 01:22:24 am
content: Quote from: Jwillis on March 25, 2023, 11:40:06 pm400kones weren't!

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: March 26, 2023, 11:27:30 am
content: These are not coated, looks like they are covered with paper label and then translucent tape.

author: Gyro
author_rank: Super Contributor
timestamp: March 26, 2023, 12:07:02 pm
content: No, those would have been for instrumentation rather than power. You didn't get 0.1% glazed power resistors.I would say, voltage dividers, bridges etc. You often find slightly-off whole number values to allow for final circuit trimming / calibration.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: March 27, 2023, 11:22:13 am
content: Someone told me that National Resistance made primarily :custom: resistorsSo they are probably for some special equipment . I agree that a bridge or some divider is a likely unit for these parts.Thanks Gyro and all others.

author: inse
author_rank: Super Contributor
timestamp: March 27, 2023, 11:59:12 am
content: National Resistance is kind of a strange company name.Sorry for being off-topic

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: March 27, 2023, 04:53:13 pm
content: Quote from: inse on March 27, 2023, 11:59:12 amYea, just try to Google it !!!!

author: MathWizard
author_rank: Super Contributor
timestamp: March 27, 2023, 08:40:41 pm
content: I looked up Biddle Bridge circuit and found this gemhttps://www.ietlabs.com/pdf/GenRad_History/A_History_of_Z_Measurement.pdf

author: Nassau Cable
author_rank: Newbie
timestamp: March 30, 2023, 09:57:40 pm
content: Hello. Wire wound resistors are commonly used in high-power and precision applications due to their high stability and accuracy. Some common applications of wire wound resistors include power supplies, audio equipment, telecommunications, and industrial controls.As for the specific brand "NAT. RES. Pearl River", it is hard to say which equipment they might have used in without more information. It is possible that they were used in a variety of equipment from that era, including military, aerospace, and industrial applications (cool, don't you think?)About what to do with it, you could consider using them in your DIY projects or selling them to other vintage electronics enthusiasts.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: March 30, 2023, 11:59:51 pm
content: I do have a Biddle Wheatstone Bridge and a GR 1650B Impedance Analyzer.Thanks for the article. Nice summary.I think these thing were used in a bridge.I think the wire is quite thin to achieve the high inductance in the small package, so I do not think they were power resistorsI was just wondering if anyone knew which particular equipment they were used in, since I do not.Someone on another group said that he had toured the National Resistance facility and that this company only made specialized resistors. Makes sense.Wally

author: donlisms
author_rank: Frequent Contributor
timestamp: March 31, 2023, 09:59:07 am
content: I don't you suppose you have any kind of chamber or other devices you could use for temperature control, eh? Finding even an approximate temperature coefficient could be a big clue to whether they are truly special, at least in some sense.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: March 31, 2023, 12:27:08 pm
content: No oven, but I will try some hot air while observing resistance on my HP 3456.

author: shapirus
author_rank: Super Contributor
timestamp: March 31, 2023, 01:15:59 pm
content: Quote from: Nassau Cable on March 30, 2023, 09:57:40 pmI may be witch-hunting, but doesn't this user look exactly like chatgpt? Check the previous posts. Do you notice that all of them have somewhat of a rather prominent common pattern?

author: LinuxHata
author_rank: Frequent Contributor
timestamp: March 31, 2023, 04:21:18 pm
content: These were used in photomultiplier tube circuits, as I remember.