A Tale of Two AC/DC Adapters

A Tale of Two AC/DC Adapters

Post by The Dawn Soliloq » Mon, 25 Aug 2003 00:02:48

A Tale of Two AC/DC Adapters, loosely based on Charles***ens work.

Being driven to a frenzy to own a "Regulated" power supply for my DX-398, I
bought the Radio Shack 273-1667 Multi-Voltage Wall Wart. It is regulated, has
an 800 ma output, and as the Multi-Voltage reference suggests, it is capable
of 3, 4.5, 6, 7.5, 9, and 12 Volts.

I bought this to replace the 273-1758 Unregulated supply at 6VDC and 300 ma.

I thought the Regulated supply would be better for the radio, since the
voltage would be held constant. When I travel, I always take the DX-398, and
this year was no exception. While using it, I noticed that when the display
light (LED) was on, it produced an unusually harsh static sound through the
speaker, usually evident only on certain frequencies, and not always limited
to the signal being weak on those frequencies. Easy enough fix, I left the
display light off.

Strange I thought, evidently a design problem with the DX-398. Eventually,
while still on vacation, I noticed that when the radio was running from the
batteries, with (of course) the AC adapter unplugged from the radio, the same
frequencies were clear of the harsh static when the display light was on or
off. As there was a transformer within 30 feet of the window of the cabin, I
attributed it to some kind of interference from that, and forgot the entire
thing.

Since we have been home a couple of weeks now, I noticed that the harsh static
was evident even here in the same way as described above. Remove the AC
adapter from the radio, and viola, the static ceased. I thought that this was
odd, as I have had the radio for a couple of year now, and only recently
noticed this problem. What of the old adapter I thought, that worthless
Unregulated supply that I bought with the radio. I substituted the Unregulated
supply for the Regulated supply. No more static, regardless of the display
being on or off.

Needless to say, I now use the Unregulated supply. Don't get me wrong, I know
that Regulated supplies are more desirable, it's just that in this case, with
the items listed by their Radio Shack numbers above, the Multi-Voltage
Regulated supply that Radio Shack offers may be more problematic in this
situation than the Unregulated supply listed for this radio.

Does anyone know of a good source of single voltage regulated AC/DC adapters?

Regards.

For those that don't understand my attempt at humor in the opening of this
post, I offer the following.

http://www.redwaveradio.com/

Never say never.
Nothing is absolute.

 
 
 

A Tale of Two AC/DC Adapters

Post by john KB5A » Mon, 25 Aug 2003 03:27:52


I don't know why you'd bother with a regulated supply, as long as the
unregulated one you use isn't one of those super-cheap Chinese ones that
delivers 20+V at no load.  RS ones don't do that.
Your radio has voltage regulation where it's needed anyway.  I'd go for the
adapter that was the smallest and with the least AC hummmmmmmmmm........

John


Quote:> A Tale of Two AC/DC Adapters, loosely based on Charles***ens work.

> Being driven to a frenzy to own a "Regulated" power supply for my DX-398,
I
> bought the Radio Shack 273-1667 Multi-Voltage Wall Wart. It is regulated,
has
> an 800 ma output, and as the Multi-Voltage reference suggests, it is
capable
> of 3, 4.5, 6, 7.5, 9, and 12 Volts.

> I bought this to replace the 273-1758 Unregulated supply at 6VDC and 300
ma.

> I thought the Regulated supply would be better for the radio, since the
> voltage would be held constant. When I travel, I always take the DX-398,
and
> this year was no exception. While using it, I noticed that when the
display
> light (LED) was on, it produced an unusually harsh static sound through
the
> speaker, usually evident only on certain frequencies, and not always
limited
> to the signal being weak on those frequencies. Easy enough fix, I left the
> display light off.

> Strange I thought, evidently a design problem with the DX-398. Eventually,
> while still on vacation, I noticed that when the radio was running from
the
> batteries, with (of course) the AC adapter unplugged from the radio, the
same
> frequencies were clear of the harsh static when the display light was on
or
> off. As there was a transformer within 30 feet of the window of the cabin,
I
> attributed it to some kind of interference from that, and forgot the
entire
> thing.

> Since we have been home a couple of weeks now, I noticed that the harsh
static
> was evident even here in the same way as described above. Remove the AC
> adapter from the radio, and viola, the static ceased. I thought that this
was
> odd, as I have had the radio for a couple of year now, and only recently
> noticed this problem. What of the old adapter I thought, that worthless
> Unregulated supply that I bought with the radio. I substituted the
Unregulated
> supply for the Regulated supply. No more static, regardless of the display
> being on or off.

> Needless to say, I now use the Unregulated supply. Don't get me wrong, I
know
> that Regulated supplies are more desirable, it's just that in this case,
with
> the items listed by their Radio Shack numbers above, the Multi-Voltage
> Regulated supply that Radio Shack offers may be more problematic in this
> situation than the Unregulated supply listed for this radio.

> Does anyone know of a good source of single voltage regulated AC/DC
adapters?

> Regards.

> For those that don't understand my attempt at humor in the opening of this
> post, I offer the following.

> http://www.redwaveradio.com/

> Never say never.
> Nothing is absolute.

 
 
 

A Tale of Two AC/DC Adapters

Post by The Dawn Soliloq » Mon, 25 Aug 2003 07:16:56

Speaking of cheap Chinese power supplies, I was fortunate enough to encounter
this link: http://www.redwaveradio.com/

I had the Skil Cordless Drill, and one day I went to recharge the battery.
After a period of time, when I went to use the drill, I noticed that it hadn't
taken a charge. I broke out the voltmeter, and discovered that the charging
receptacle had no voltage. When I finally looked at the transformer, I noticed
that it had melted and distorted the case considerably. When I was looking for
a replacement battery for the drill, I came across the recall.

Skil quickly handled the recall, I was sent a UPS shipping label to attach to
the boxed drill to return to Skil. I didn't even need to pay postage. A couple
of weeks later, I received a new drill, a newer but comparable model. Although
I appreciate the new drill, when I recharged it, the transformer still gets
very hot. Am I missing something here? I think that may be in for recall, Part
II.

This unit was made in China, as was the device that I bought that would dim a
table lamp when the lamp was touched. You just plugged it into the wall,
plugged the lamp into the device, and viola, it worked. Some time later,
months, it ceased working. The device was behind the couch, with more than
adequate ventilation. It had apparently melted, and had it caught fire, I may
have lost the house.

Thanks China and those manufacturers that care so little about their customers
that they will buy any cheap product that they can.

Regards.



>I don't know why you'd bother with a regulated supply, as long as the
>unregulated one you use isn't one of those super-cheap Chinese ones that
>delivers 20+V at no load.  RS ones don't do that.
>Your radio has voltage regulation where it's needed anyway.  I'd go for the
>adapter that was the smallest and with the least AC hummmmmmmmmm........

>John


>> A Tale of Two AC/DC Adapters, loosely based on Charles***ens work.

>> Being driven to a frenzy to own a "Regulated" power supply for my DX-398,
>I
>> bought the Radio Shack 273-1667 Multi-Voltage Wall Wart. It is regulated,
>has
>> an 800 ma output, and as the Multi-Voltage reference suggests, it is
>capable
>> of 3, 4.5, 6, 7.5, 9, and 12 Volts.

>> I bought this to replace the 273-1758 Unregulated supply at 6VDC and 300
>ma.

>> I thought the Regulated supply would be better for the radio, since the
>> voltage would be held constant. When I travel, I always take the DX-398,
>and
>> this year was no exception. While using it, I noticed that when the
>display
>> light (LED) was on, it produced an unusually harsh static sound through
>the
>> speaker, usually evident only on certain frequencies, and not always
>limited
>> to the signal being weak on those frequencies. Easy enough fix, I left the
>> display light off.

>> Strange I thought, evidently a design problem with the DX-398. Eventually,
>> while still on vacation, I noticed that when the radio was running from
>the
>> batteries, with (of course) the AC adapter unplugged from the radio, the
>same
>> frequencies were clear of the harsh static when the display light was on
>or
>> off. As there was a transformer within 30 feet of the window of the cabin,
>I
>> attributed it to some kind of interference from that, and forgot the
>entire
>> thing.

>> Since we have been home a couple of weeks now, I noticed that the harsh
>static
>> was evident even here in the same way as described above. Remove the AC
>> adapter from the radio, and viola, the static ceased. I thought that this
>was
>> odd, as I have had the radio for a couple of year now, and only recently
>> noticed this problem. What of the old adapter I thought, that worthless
>> Unregulated supply that I bought with the radio. I substituted the
>Unregulated
>> supply for the Regulated supply. No more static, regardless of the display
>> being on or off.

>> Needless to say, I now use the Unregulated supply. Don't get me wrong, I
>know
>> that Regulated supplies are more desirable, it's just that in this case,
>with
>> the items listed by their Radio Shack numbers above, the Multi-Voltage
>> Regulated supply that Radio Shack offers may be more problematic in this
>> situation than the Unregulated supply listed for this radio.

>> Does anyone know of a good source of single voltage regulated AC/DC
>adapters?

>> Regards.

>> For those that don't understand my attempt at humor in the opening of this
>> post, I offer the following.

>> http://www.redwaveradio.com/

>> Never say never.
>> Nothing is absolute.

Never say never.
Nothing is absolute.