Спутниковый приёмник показал координаты.

Координаты is in the accusative case because it is the direct object of the verb показал: it is the thing that was shown.

In this sentence:

• Спутниковый приёмник = the subject
• показал = the verb
• координаты = the object

For inanimate plural nouns, the accusative is usually the same as the nominative, so координаты looks the same in both cases.

The ending -л shows that the verb is in the past tense.

Russian past tense is formed from the infinitive stem plus endings that agree with gender and number:

• показал = masculine singular
• показала = feminine singular
• показало = neuter singular
• показали = plural

Since приёмник is a masculine singular noun, the verb is показал.

In Russian, a noun ending in a consonant is usually masculine.
Приёмник ends in -к, so it is masculine.

That matters because adjectives and past-tense verbs must agree with it:

• спутниковый приёмник
• приёмник показал

Both the adjective спутниковый and the verb показал match a masculine singular noun.

Спутник is a noun meaning satellite.
Спутниковый is an adjective meaning satellite- or of a satellite.

So:

• спутник = a satellite
• спутниковый приёмник = a satellite receiver

This is very common in Russian: a noun is turned into an adjective to describe another noun.

Other similar patterns:

• спорт → спортивный
• музыка → музыкальный

By itself, приёмник is a general word meaning receiver. Depending on context, it could mean:

• a radio receiver
• a signal receiver
• a GPS/satellite receiver

Because it is modified by спутниковый, the phrase спутниковый приёмник strongly suggests a satellite receiver, and in many contexts that may indeed mean a GPS receiver.

So the exact English translation can depend on context.

Russian has no articles, so there is no direct equivalent of the or a/an.

That means Спутниковый приёмник показал координаты could be understood as:

• The satellite receiver showed the coordinates
• A satellite receiver showed coordinates

Which one sounds best depends on context. English requires an article, but Russian does not.

Yes. Russian word order is more flexible than English because case endings show the grammatical roles.

The neutral order here is:

• Спутниковый приёмник показал координаты.

But you could also say:

• Координаты показал спутниковый приёмник.

That would put more emphasis on координаты or on the contrast of what showed them.

Even though the word order changes, координаты is still the object and приёмник is still the subject.

Приёмник is pronounced roughly pri-YOM-neek.

Important points:

• The letter ё is always stressed.
• ё sounds like yo.
• So приёмник has stress on the middle syllable: при-Ём-ник.

In printed Russian, ё is sometimes written as е, especially in less careful writing, so you may see приемник. But the correct pronunciation is still приёмник.

Usually, yes, when talking about geographic coordinates or a set of coordinates.

That is because coordinates normally come as more than one value, such as:

• latitude and longitude
• x and y
• x, y, and z

So Russian commonly uses the plural координаты.

There is also a singular form координата, but it usually means one coordinate.

Показал is perfective.

The infinitive pair is:

• показывать = imperfective
• показать = perfective

In the past tense:

• показывал = was showing / used to show
• показал = showed, indicated, displayed

The perfective is used here because the sentence presents the action as a completed event/result: the receiver produced or displayed the coordinates.

Yes. In Russian, показать is quite broad. Depending on context, it can mean:

• show
• display
• indicate
• reveal

So in a technical sentence like this, Спутниковый приёмник показал координаты could naturally be translated as:

• The satellite receiver showed the coordinates
• The satellite receiver displayed the coordinates
• The satellite receiver indicated the coordinates

All are possible, depending on the style of translation.