What's a dBu ?
 

"
Should be relative to a microvolt into a 600 Ohm load.

Forget microVolt!
0 dBu is steady AF established at 775 milliVolts line level -- regardless
of load Z.

It is an easy mistake to make, because dB relative to a microvolt is often
written as dBu rather than
using the Greek letter 'mu'; a limitation of the ASCII character set!!

Jeff

What's a dBu ?
 

On Mon, 7 Nov 2005 15:41:48 -0000, "Jeff" wrote:


"
Should be relative to a microvolt into a 600 Ohm load.

Forget microVolt!
0 dBu is steady AF established at 775 milliVolts line level -- regardless
of load Z.

It is an easy mistake to make, because dB relative to a microvolt is often
written as dBu rather than
using the Greek letter 'mu'; a limitation of the ASCII character set!!

Jeff


dB relative to a microvolt is written as dBuV, so there need be no
confusion.

d
Pearce Consulting
http://www.pearce.uk.com

What's a dBu ?
 

In article , Don Pearce
writes
On Mon, 7 Nov 2005 15:41:48 -0000, "Jeff" wrote:


"
Should be relative to a microvolt into a 600 Ohm load.

Forget microVolt!
0 dBu is steady AF established at 775 milliVolts line level -- regardless
of load Z.

It is an easy mistake to make, because dB relative to a microvolt is often
written as dBu rather than
using the Greek letter 'mu'; a limitation of the ASCII character set!!

Jeff


dB relative to a microvolt is written as dBuV, so there need be no
confusion.

Rather as dB relative to one miliwatt should be written dBmW to avoid
people thinking it is miliampere. The unit should always be specified
where there is potential for confusion, although current practice can
omit it.

--
Ian G8ILZ

What's a dBu ?
 

It is an easy mistake to make, because dB relative to a microvolt is often
written as dBu rather than
using the Greek letter 'mu'; a limitation of the ASCII character set!!

Jeff


dB relative to a microvolt is written as dBuV, so there need be no
confusion.


Well I am afraid that RF engineers are a lazy breed and it is often written
as dBu, much in the same way as dBm.

Jeff

What's a dBu ?
 

On Mon, 7 Nov 2005 19:30:34 +0000, Prometheus
wrote:

In article , Don Pearce
writes
On Mon, 7 Nov 2005 15:41:48 -0000, "Jeff" wrote:


"
Should be relative to a microvolt into a 600 Ohm load.

Forget microVolt!
0 dBu is steady AF established at 775 milliVolts line level -- regardless
of load Z.

It is an easy mistake to make, because dB relative to a microvolt is often
written as dBu rather than
using the Greek letter 'mu'; a limitation of the ASCII character set!!

Jeff


dB relative to a microvolt is written as dBuV, so there need be no
confusion.

Rather as dB relative to one miliwatt should be written dBmW to avoid
people thinking it is miliampere. The unit should always be specified
where there is potential for confusion, although current practice can
omit it.

Far too late, I'm afraid. The dBm is far too well established.

d

Pearce Consulting
http://www.pearce.uk.com

What's a dBu ?
 

In message , Jeff
writes

It is an easy mistake to make, because dB relative to a microvolt is often
written as dBu rather than
using the Greek letter 'mu'; a limitation of the ASCII character set!!

Jeff


dB relative to a microvolt is written as dBuV, so there need be no
confusion.


Well I am afraid that RF engineers are a lazy breed and it is often written
as dBu, much in the same way as dBm.

Jeff


After 41 years in the cable TV industry, I've NEVER seen dBmV or dBμV
written abbreviated. Spoken, you occasionally hear only 'dB' from the
careless.
Ian.
--

What's a dBu ?
 

On Mon, 7 Nov 2005 19:39:02 -0000, "Jeff" wrote:


It is an easy mistake to make, because dB relative to a microvolt is often
written as dBu rather than
using the Greek letter 'mu'; a limitation of the ASCII character set!!

Jeff


dB relative to a microvolt is written as dBuV, so there need be no
confusion.


Well I am afraid that RF engineers are a lazy breed and it is often written
as dBu, much in the same way as dBm.

Jeff


Well, I've been an RF engineer all my life, and I've never come across
dBu instead of dBuV.

d

Pearce Consulting
http://www.pearce.uk.com

What's a dBu ?
 

Well, I've been an RF engineer all my life, and I've never come across
dBu instead of dBuV.


Obviously Pearce Consulting are not as lazy as some!! (;_))

Jeff

What's a dBu ?
 

On Mon, 7 Nov 2005 20:02:15 -0000, "Jeff" wrote:

Well, I've been an RF engineer all my life, and I've never come across
dBu instead of dBuV.


Obviously Pearce Consulting are not as lazy as some!! (;_))

Jeff


Mmmmm..... I reckon it's just you. ;-)

d

Pearce Consulting
http://www.pearce.uk.com

What's a dBu ?
 

Mmmmm..... I reckon it's just you. ;-)

d

Pearce Consulting
http://www.pearce.uk.com

Then try doing a little research on the web then, you will find at least
four usages of "dBu".

The correct one,

dB rel 1 micro volt, when written without access to mu,

dB rel 1 micro volt/m (used by the FCC)

and dB rel 1 micro Watt (mainly sat downlink people).

Regards
Jeff