Michael A. Terrell wrote:
Unrevealed Source wrote:

In general, is it better to run a receiver off a good external DC power
supply, or using AC power and the built-in transformer? It would seem to me
that I might get less noise using an external DC power supply, but what is
the general concensus here? Thanks.

Jeff



What do you base this on? Why do you think an external supply is
better or quieter than the one designed for the radio?


I have to agree with Michael.

A power supply can be well designed or poorly designed. A poorly
designed supply is a pain in both internal or external form. It doesn't
matter if a well designed supply is internal or external.

Some may prefer external supplies as they can power more than one radio
at a time from a single supply.

There is also the belief that removing the heat generated by a supply by
using an external supply improves the reliability of the radio. However,
I have only seen anecdotal evidence to support this.

However, an external supply is easier to replace. Generally a plus if
you have a radio that comes with a poor supply.

If you mode the radio around a lot, an internal supply may be more
convenient.

With respect to noise, it may be easier to block powerline noise with an
external supply. This is because you can add filters to the input and
output of the supply to block noise at a short distance away from the radio.

With respect to noise generated within the power supply, excessive noise
would be an indication of a poorly design supply. That can apply to
internal and external supplies.

If the supply is internal, the manufacturer has control of the quality.
They have the ability ensure the supply is properly designed for the
application.

If the supply is external, the user is free to use a really poor supply
of their choice and possibly be unhappy with the radio's performance.

If you are considering using a third party supply with a radio, how
would you go about determining of the supply you are about to buy is
really better than the one supplied by the manufacturer? Trial and error
is an expensive method.

Fortunately, many radios with internal supplies also support use of an
external supply. The user is free to try an external supply.

With respect to your original question, you are correct, you "might get
less noise" but that really depends upon you choice of external supply.
A bad supply could be much noisier than the internal supply.

Craigm