Answer / nirmal

yes , digital signal can send in air with out modulation .
but it is for very small distance . (baseband modulation ).
to increase the distance to be covered , power of
transmitters should be very high .
digital signal is always a pcm signal so it is already
modulated. but no avialability of carrier it is used for
wired communication . for larger distance digital
modulation is used. so digital modulation is called double
modulation.

The property of a metal that is determined by the indentation on a metal surface

0 Answers   HAL,

---

what is the difference between isdn and idn?

0 Answers   Sony,

---

What is the difference between masking and non-masking?

0 Answers  

---

Explain why vestigial side band is used in tv signal transmission?

0 Answers  

---

wat sud b the futher course after b.tech in this field........

1 Answers  

---

---

which are the companies taking asl1 freshers

1 Answers  

---

What is the difference between generator differential protection and transformer differential protection??

0 Answers   TATA,

---

Which modulation is good for Radio Broadcasting. AM(Amplitude Modulation) or FM(Frequency Modulation)?

7 Answers   TCS, Vodafone,

---

WHEN DO WE USE CAPACITOR AND INDUCTOR AS STORING DEVICE?

2 Answers  

---

Tell me why Up link Frequency is more than Down link frequency.?

1 Answers   Mobilink,

---

What do you mean by ASCII, EBCDIC?

11 Answers  

---

Define lock-inrange, capture range, and pullintime of a pll

0 Answers  

---