Dale Electronics
RN55D7501F 7.5K Ohm 1% Precision Metal Film Resistor, Axial, MIL-R-10509 Type RN55
- 6 photos
Never used and never opened. Still in the factory tube, tray, reel or bag it shipped in, with the original date code intact.
New old stock, sealed on the grading scaleSend the quantity you need. You get a quote back with shipping before anything is charged.
Video
Filmed on the bench. Sound is stripped from product clips.
- 0:10
The clip opens on the hub, where the distributor label is torn back around the core insert.
Specifications
| Specification | Value |
|---|---|
| Identification | |
| Part number | RN55D7501F |
| Manufacturer | Dale Electronics |
| Condition | New old stock, sealed |
| Date code | 9903 |
| Package | Axial leaded |
| Country of origin | Not recorded |
| Family | Not recorded |
| Stock number | 9V4JS2M9 |
| Electrical | |
| Resistance | 7.5kilohm |
| Tolerance | 1% |
| Temperature coefficient | 100ppm/C |
| Characteristic code | D |
| Power rating at 70 C | 0.125W |
| Power rating at 125 C | 0.10W |
| Maximum working voltage | 200V |
| Dielectric strength | 450VAC |
| Voltage coefficient | 5ppm/V |
| Noise | -40dB |
| Operating temperature range | -65 to +175C |
| Construction | |
| Resistive element | Nickel chrome alloy film |
| Core | Fire cleaned high purity ceramic |
| Coating | Flame retardant epoxy |
| Termination | Solder coated copper, solderable and weldable |
| Mechanical | |
| Body length | 0.240 +/- 0.020 in (6.10 +/- 0.51 mm) |
| Body diameter | 0.090 +/- 0.008 in (2.29 +/- 0.20 mm) |
| Lead diameter | 0.025 +/- 0.002 in (0.64 +/- 0.05 mm) |
| Qualification | |
| Military style | RN55, MIL-R-10509/7 |
| Vishay Dale model | CMF55 |
| This lot | |
| Lot quantity on the reel label | 1000 |
| Distributor part number | DALRN55D7501FTR |
| Manufacturer CAGE code | 91637 |
| JAN qualified | Yes, the packing label reads JAN: Y |
| Date code | 9903 |
| Packing type | Type CT55 tape and reel |
About this part
RN55D7501F is a 7.5 kilohm precision metal film axial resistor built to the MIL-R-10509 type RN55 style, specification sheet /7. The Vishay Dale model designation for the same part is CMF55. The number reads as a set of fields: RN55 is the MIL style, D is the temperature coefficient characteristic at plus or minus 100 ppm per degree C, 7501 is 750 followed by one zero for 7500 ohms, and F is the plus or minus 1 percent tolerance.
Construction is a nickel chrome alloy film on a fire cleaned high purity ceramic core, sealed in flame retardant epoxy, on solder coated copper leads that take solder or resistance welding. Dale rates the RN55 at 0.125 W at 70 degrees C and 0.10 W at 125 degrees C, with a 200 V maximum working voltage. Parts in this style were specified where drift mattered more than cost: instrumentation, avionics, test gear, medical equipment and military assemblies. Noise is low, around -40 dB, and the voltage coefficient is 5 ppm per volt.
When buying old stock, check the leads first. Solder coated copper tarnishes in storage and the oxide fights a soldering iron, so plan on cleaning or retinning. Read the printed style, characteristic letter and value off the body rather than trusting a bin label.
Questions about this part
Is RN55D7501F metal film or carbon film?
Metal film. The RN styles under MIL-R-10509 use a nickel chrome alloy film on a ceramic core. The carbon film military styles are the RL types under MIL-PRF-22684, which is a different specification.
What does each part of the number mean?
RN55 is the MIL style and case size, D is the temperature coefficient characteristic at plus or minus 100 ppm per degree C, 7501 is three significant figures plus a multiplier for 7500 ohms, and F is the plus or minus 1 percent tolerance.
What is the power rating?
0.125 W at 70 degrees C and 0.10 W at 125 degrees C, with derating above that. Maximum working voltage is 200 V, or the square root of power times resistance, whichever is lower.
Will these fit where a modern 1/4 watt resistor sits?
The body is 6.10 mm long by 2.29 mm diameter, the same size as a typical modern 1/4 watt axial. Power handling is lower, so check the dissipation in the circuit rather than assuming it is a drop in.
Do these carry a JAN marking?
RN parts screened and branded to the military specification carry a J for JAN plus a date code on the body. Whether a given lot is JAN branded or commercial grade depends on the lot, so read the body marking.
How stable are these in storage?
Vishay Dale states that resistance shifts due to storage at room temperature are negligible. The practical storage issue is lead solderability, not resistance drift.
What tolerances were offered in this style?
The RN55 style is offered at plus or minus 0.1, 0.25, 0.5 and 1 percent, but the tighter three are not applicable to characteristic D. A characteristic D part is a 1 percent part, which is what the F code means.