Ril WW Resistors - UK Vintage Radio Repair and Restoration Discussion Forum

David Simpson · 17th Mar 2018, 4:32 pm

Just been given a box full of high wattage WW Resistors. In amongst them were several Ril types. I've taken a picture of three of them - L to R - Type 42, Type 43 & Type 44.
The l/h one is designated "Ril Type 42", the middle one is a Rivlin Instruments Ltd Precision Resistor Type 43, & the r/h one is a hand written Ril 44. Google reveals that Rivlin made Inductive & non Inductive WW resistors. Other research reveals these 4 wire resistors can be used in a bridge format.
Quite frankly, I cant remember coming across them before. If they were used in T/Eq or other circuitry, I've never had to replace any.
Any info most welcome please ?

Regards, David

PS My apologies for picture's poor focus

Station X · 17th Mar 2018, 4:56 pm

Have you tried using the macro setting on your camera, assuming it is a camera and not a phone?

Refugee · 17th Mar 2018, 5:24 pm

What tolerance are they?
I have seen 0.025% ones in test equipment that I own.
As Graham says a better photo would be good.

David Simpson · 17th Mar 2018, 5:37 pm

Aye Graham,
I have made the effort, but it's a bit hit & miss. I use a Mintola digital camera which is now coming up 13 years old. It was 60th birthday present. So I guess the dual aging process, and usage, has maybe affected both the camera & myself. I'll maybe get it checked out at Jessops Aberdeen shop.(Whilst I visit Specsavers).

Regards, David

PS. Bye the way, I've just spoken with the chap who gave me the box of resistors this morning, & he says that, in turn, some years ago, he was originally given the box by a retired TV & Video shop owner who's retirement hobby was restoring vintage video equipment. However, he'd not used any Ril resistors himself. DS

ms660 · 17th Mar 2018, 5:53 pm

Sensing....Kelvin configuration?

Lawrence.

David Simpson · 17th Mar 2018, 7:14 pm

I don't know about 0.025% tolerance, but some of the written resistances are either 0.015 ohms or 0.025 ohms. Tolerances on most are either written as 0.5% or 1.0%. The highest written resistance(on the black resin encapsulated type 43's) is 16.7 ohms. I've just the one resin enc. Type 42 & that is 0.025 ohms with 1.0% tol. The blue vitreous Type 44's are all 0.015 ohms with 1% tol.
The higher value ones seem to measure their resistances lengthwise, but at the ends they would seem to be less than 0.1 ohm between the wires. My cheapo RS LCR meter doesn't go below 0.1ohm. I'll maybe try my Marconi TF2700.

Regards, David

Radio Wrangler · 17th Mar 2018, 7:32 pm

You may find that the resistances of the resistors are somewhat higher than the printed amounts but the amount of that resistance which lies between the two sense wire pickoff points may be more accurate. If so then they would be current sensing items rather than precision resistors.

David

Refugee · 18th Mar 2018, 12:23 am

They sound like they might be amps range shunts from something like an early multi meter.

David Simpson · 18th Mar 2018, 12:33 pm

A local VMARS chum has suggested they might be used to compensate for metering lead resistance &/or shunt or multiplier lead resistance - for accurate calibration. Hence their low decimal point resistances.
For those resistors greater than 1 ohm - my cheapo RS LCR meter gets close-ish, but my AVO/Newlec DMM get much closer to 2 decimal points. Wish I hadn't flogged my Wayne Kerr B221 at times like this. An interesting wee exercise if nothing else.

Regards, David

17th Mar 2018, 4:32 pm	#1
David Simpson Nonode Join Date: Mar 2008 Location: Aberdeen, UK. Posts: 2,853	Ril WW Resistors Just been given a box full of high wattage WW Resistors. In amongst them were several Ril types. I've taken a picture of three of them - L to R - Type 42, Type 43 & Type 44. The l/h one is designated "Ril Type 42", the middle one is a Rivlin Instruments Ltd Precision Resistor Type 43, & the r/h one is a hand written Ril 44. Google reveals that Rivlin made Inductive & non Inductive WW resistors. Other research reveals these 4 wire resistors can be used in a bridge format. Quite frankly, I cant remember coming across them before. If they were used in T/Eq or other circuitry, I've never had to replace any. Any info most welcome please ? Regards, David PS My apologies for picture's poor focus Attached Thumbnails Last edited by David Simpson; 17th Mar 2018 at 4:34 pm. Reason: Picture quality

17th Mar 2018, 4:56 pm	#2
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Ril WW Resistors Have you tried using the macro setting on your camera, assuming it is a camera and not a phone? __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

17th Mar 2018, 5:24 pm	#3
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,553	Re: Ril WW Resistors What tolerance are they? I have seen 0.025% ones in test equipment that I own. As Graham says a better photo would be good.

17th Mar 2018, 5:37 pm	#4
David Simpson Nonode Join Date: Mar 2008 Location: Aberdeen, UK. Posts: 2,853	Re: Ril WW Resistors Aye Graham, I have made the effort, but it's a bit hit & miss. I use a Mintola digital camera which is now coming up 13 years old. It was 60th birthday present. So I guess the dual aging process, and usage, has maybe affected both the camera & myself. I'll maybe get it checked out at Jessops Aberdeen shop.(Whilst I visit Specsavers). Regards, David PS. Bye the way, I've just spoken with the chap who gave me the box of resistors this morning, & he says that, in turn, some years ago, he was originally given the box by a retired TV & Video shop owner who's retirement hobby was restoring vintage video equipment. However, he'd not used any Ril resistors himself. DS

17th Mar 2018, 5:53 pm	#5
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Ril WW Resistors Sensing....Kelvin configuration? Lawrence.

17th Mar 2018, 7:14 pm	#6
David Simpson Nonode Join Date: Mar 2008 Location: Aberdeen, UK. Posts: 2,853	Re: Ril WW Resistors I don't know about 0.025% tolerance, but some of the written resistances are either 0.015 ohms or 0.025 ohms. Tolerances on most are either written as 0.5% or 1.0%. The highest written resistance(on the black resin encapsulated type 43's) is 16.7 ohms. I've just the one resin enc. Type 42 & that is 0.025 ohms with 1.0% tol. The blue vitreous Type 44's are all 0.015 ohms with 1% tol. The higher value ones seem to measure their resistances lengthwise, but at the ends they would seem to be less than 0.1 ohm between the wires. My cheapo RS LCR meter doesn't go below 0.1ohm. I'll maybe try my Marconi TF2700. Regards, David

17th Mar 2018, 7:32 pm	#7
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,867	Re: Ril WW Resistors You may find that the resistances of the resistors are somewhat higher than the printed amounts but the amount of that resistance which lies between the two sense wire pickoff points may be more accurate. If so then they would be current sensing items rather than precision resistors. David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done

18th Mar 2018, 12:23 am	#8
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 5,553	Re: Ril WW Resistors They sound like they might be amps range shunts from something like an early multi meter.

18th Mar 2018, 12:33 pm	#9
David Simpson Nonode Join Date: Mar 2008 Location: Aberdeen, UK. Posts: 2,853	Re: Ril WW Resistors A local VMARS chum has suggested they might be used to compensate for metering lead resistance &/or shunt or multiplier lead resistance - for accurate calibration. Hence their low decimal point resistances. For those resistors greater than 1 ohm - my cheapo RS LCR meter gets close-ish, but my AVO/Newlec DMM get much closer to 2 decimal points. Wish I hadn't flogged my Wayne Kerr B221 at times like this. An interesting wee exercise if nothing else. Regards, David