P. R. Mallory and Co.
Mallory MTA100F35 100uF 35V Axial Aluminum Electrolytic Capacitor, Molded Tubular
- 2 photos
Never used. The original pack has been opened, or the quantity was split off a full reel or tube. Leads are original and unclipped.
New old stock, open stock 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.
- 0:11
Video still showing the part held between fingers for scale.
Specifications
| Specification | Value |
|---|---|
| Identification | |
| Part number | MTA100F35 |
| Manufacturer | P. R. Mallory and Co. |
| Condition | New old stock, open stock |
| Date code | Not recorded |
| Package | Axial leaded |
| Country of origin | Not recorded |
| Family | Not recorded |
| Stock number | 9V4JS2MB |
| Electrical | |
| Capacitance | 100microfarad |
| Working voltage | 35VDC |
| Surge voltage | 40VDC |
| Capacitance tolerance | -10 to +100% |
| Operating temperature range | -20 to +65C |
| Construction | |
| Dielectric | Aluminum electrolytic, polarized |
| Case material | Precision molded polypropylene |
| Internal construction | All welded |
| Mechanical | |
| Case size code | F |
| Ordering | |
| Series | MTA, molded tubular aluminum electrolytic |
| This lot | |
| Full marking on the body | MALLORY 100MFD 35VDC MTA100F35 BKA |
| BKA suffix | Present on the body. Not found in any Mallory catalogue, so its meaning is unconfirmed. |
About this part
MTA100F35 is a Mallory molded tubular aluminum electrolytic capacitor, 100 microfarads at 35 working volts DC, with a 40 volt surge rating in a case size F body. The number decodes directly against Mallory's own catalogue: MTA is the series, 100 is the capacitance in microfarads, F is the case size and 35 is the working voltage.
Mallory built the MTA line by precision molding rather than the older tube and fill method, using a polypropylene case chosen to keep water molecules out while still allowing the electrolyte to vent at a molecular level. Internal construction is all welded. Mallory catalogued the series at a -20 to +65 degree C temperature range with a capacitance tolerance of -10 percent to +100 percent, wide by modern standards but ordinary for general purpose electrolytics of that period. Parts like this turn up in consumer audio, radio, instrument and industrial equipment, and they are familiar to anyone doing restoration work.
Old stock aluminum electrolytics need judgement rather than a datasheet. The oxide film degrades in storage, leakage current climbs, and a capacitor that has sat unpowered for decades may need slow reforming on a current limited supply before it is trusted at rated voltage. Measure capacitance and leakage before installing, and confirm the polarity marking is still readable.
Questions about this part
What does MTA100F35 stand for?
MTA is Mallory's molded tubular aluminum electrolytic series, 100 is the capacitance in microfarads, F is the case size code, and 35 is the maximum working voltage in DC volts. The matching surge rating is 40 VDC.
Are these axial or radial?
Axial. The MTA series is the axial two lead molded tubular type. Mallory's molded radial equivalent of the era was the MTV vertical mount series.
What is the tolerance?
Mallory published the MTA series at -10 percent to +100 percent. That asymmetric spread was normal for general purpose aluminum electrolytics and is why these should never be used where the value must be held closely.
Do these need reforming before use?
Assume yes for any aluminum electrolytic stored a long time unpowered. Bring the voltage up slowly through a current limiting resistor while watching the current fall. If leakage will not settle, the part is not usable.
What is the temperature rating?
Mallory catalogued the MTA series at -20 to +65 degrees C. That is narrower than a modern 85 or 105 degree C part, so it is not a like for like substitute in a hot chassis position.
Is there a modern replacement?
Any 100 microfarad 35 V or higher axial aluminum electrolytic with an 85 or 105 degree C rating will substitute electrically, and will be physically smaller with a tighter tolerance.
What does the case size F tell me?
It selects a body diameter and length from Mallory's MTA case size table. Case F is the largest of the three sizes used across the MTA stock list. Measure the physical part for exact dimensions.