Help confusing components

[Colinchandler]

Can anyone help the newby please?
I don't know wether the brown one is a cap or resistor, how can you tell?
And the blue one must be a resistor, I don't know the voltage or value
Thankyou colin

[Station X]

The brown component is a capacitor and judging by its construction I'd say it's pretty reliable, but I have no personal experience of this make.

As a general, but not infallible, rule resistors are colour coded with their value whereas capacitors have their values written on them. The fact that the brown component has a voltage reading written on it indicates it's a capacitor. You wouldn't see that on a resistor.

[Alf]

Value, 100K or 100,000nF or 0.1µF?

[turretslug]

The blue stripey component could well actually be a capacitor, the suspicion reinforced by the slimmer brown stripeys around it definitely being resistors. The value may well be 47,000pF, i.e. 47nF or 0.047uF. It looks to be in something like an AGC filter or similar grid biasing/filtering circuit, in which case 47nF would be a reasonable value in conjunction with the 2.2 Megohm resistor. Or possibly a small signal pentode screen-grid feed, again 47nF would be sensible. Resistor colour coding is pretty dependable but capacitor makers often had their own pet colour allocations for working voltage in particular, sometimes other parameters.

With passive components, there are always awkward exceptions to visual identification rules and the problem only got worse as time went on! A DMM with capacitance measurement option can be a boon, and this function can be had quite cheaply,

Colin

[crackle]

Originally Posted by Alf

Value, 100K or 100,000nF or 0.1µF?

I think there is a typo in there I think it is 100,000pF or 0.1µF

Mike

[Lucien Nunes]

I don't know wether the brown one is a cap or resistor, how can you tell?

Larger parts in moulded smooth plastic cases are invariably capacitors. Large resistors dissipate significant heat, for which a plastic case is unsuitable. Plastic cases were sometimes used for small precision resistors, but these are rarely found outside lab equipment.

Anything with a voltage rating printed on the outside is usually a capacitor, as this is one of the two most important parameters of the cap. Resistors have a maximum voltage rating too, but in general it is not of great interest and not shown on the part. The only time we generally need to consider it is when using high values of small, modern resistors in valve circuits with high voltages. The power rating is sometimes printed on higher power resistors, though, as this is often an important parameter. Otherwise, you have to identify power ratings by the dimensions and construction of the resistor. There are half a dozen common power ratings to recognise.

But the best way to determine what you are looking at is to identify its function in the circuit. Sets typically consist of a number of distnict signal 'stages' i.e. building blocks, each of fairly standard configuration, often one or two per valve. Each stage will have a number of passive components associated with it, that will usually follow some pretty rigid conventions and hence become easy to recognise with practice.

E2A: When asking about component identification, please give details of the unit they are from. Knowing the context helps considerably, and there are people here who could draw out the circuit of many popular items from memory. Even if one doesn't know the specifics, knowing the function of a device gives many clues. I am guessing from the circuit and pictures that this is a piece of music equipment...

[G8HQP Dave]

When I first saw the blue one my first thought was inductor, but depending on where it is in the circuit maybe capacitor is more likely. It is unlikely to be a resistor, because resistors are not usually encased in plastic.

[AC/HL]

Is this your Meazzi again? If so, what is the model number?

[John10b]

Hi Colin just for you to know that after being involved with Electronics for many years I still can have difficulty identifying a component with absolute certainty, I always look at the circuit diagram ( if available) or seek advice before coming to a decision.
Cheers
John