Telamon wrote in message

....
That's odd as they normally sound good here with no hum.

Sometimes noise on the AC power can get into the antenna-radio system
and mess up certain frequencies. I have had power strips with built in
filters that have caused problems instead of making things better.

--
Telamon
Ventura, California

Maybe the problem is here on my end. The Hum was on all 3 freq.
9.515....13.655....& 17.800. Also I don't hear it on any other
stations...well other than the ones I mentioned before.

Oh well enough of that I guess.

73 es DX Ken

In article ,
"Ken Wilson" wrote:

Telamon wrote in message

...
That's odd as they normally sound good here with no hum.

Sometimes noise on the AC power can get into the antenna-radio system
and mess up certain frequencies. I have had power strips with built in
filters that have caused problems instead of making things better.

--
Telamon
Ventura, California

Maybe the problem is here on my end. The Hum was on all 3 freq.
9.515....13.655....& 17.800. Also I don't hear it on any other
stations...well other than the ones I mentioned before.

Oh well enough of that I guess.

I encourage you to look into it a little more. No sense letting
something like this spoil your listening. If you have a decent portable
radio (on batteries of course) you could check if the hum is heard on
the portable. If it is then it's real. If not then is could be an
interaction of the AC power, your radio and antenna. I have had this
happen only on specific frequencies with the radio plugged into a
problem AC power strip filter.

--
Telamon
Ventura, California

The usual hum source is nonbypassed diodes in the wall wart, which
provide a nice RF ground when they conduct and none when they don't,
thus changing the antenna system 120 times a second when there's an
instant that they're all not conducting at once.

Even if you ground the radio yourself, they still change the antenna
system, though usually it matters less the more grounded the radio is.

One test is whether the hum changes if you hold a hand on the radio,
improving its RF ground a bit.

The fix is a wall wart with bypassed diodes, or NiMH batteries, which
are good enough these days so you don't really need the wall wart.
Just swap a battery set when needed.
--
Ron Hardin


On the internet, nobody knows you're a jerk.

On Sun, 22 Aug 2004 02:58:27 -0500, Ron Hardin wrote
(in article ):

The usual hum source is nonbypassed diodes in the wall wart, which
provide a nice RF ground when they conduct and none when they don't,
thus changing the antenna system 120 times a second when there's an
instant that they're all not conducting at once.

Even if you ground the radio yourself, they still change the antenna
system, though usually it matters less the more grounded the radio is.

One test is whether the hum changes if you hold a hand on the radio,
improving its RF ground a bit.

The fix is a wall wart with bypassed diodes,

I've got six or seven wallwarts from TadioShack and have never had a
problem.

or NiMH batteries, which
are good enough these days so you don't really need the wall wart.
Just swap a battery set when needed.


Absolutely, we use NiMH on my wife's radios which are liable to be
anywhere in the entire household.

Except: I just don't like doing that with AA's cuz they're so small (in
"playtime") that I don't like jerking them in and out so often.

So I use a "C" cell "battery holder" from RShack and one of their $3
cords and plug the thing into external DC power.

Ron's probably already figured out why I specify "C" cells rather than
"D" but in case anyone is wondering, 2 or 3 sets of rechargeable "D"
cells cost a buncha $$$. If ya got no problems with spending $$$, find
out who is a good electrician in your area and get him/her to run you a
dedicated and filtered/shielded outlet(s) for your radio gear (and
another for your computer gear as long as you're going to the bother
[grin]).


++ Gray //

Gray Shockley wrote:
So I use a "C" cell "battery holder" from RShack and one of their $3
cords and plug the thing into external DC power.

Add a fuse to the line; they can start a fire if something shorts at the radio end.

Presumably it matters less if the batteries are internal to the radio.
--
Ron Hardin


On the internet, nobody knows you're a jerk.