Re: Elecraft Digest, Vol 89, Issue 15

[vk3dbd]

Re:] Switch mode PSU

I just read the comments and reply in the message below:
I have both those PSU, the Sec 1223  is by far the oldest one. It has
several" birdies"   best described as rather Raucous Crows, which get worse
as the frequency goes lower. 160m is pretty poor.   I added several devices
in attempts to quieten same, which was achieved to some degree.  It is
acceptable on all but 160m,   where it appears in about 3 places across the
band, (not always the same places)  The Waters and Stanton  Power Mite is
cheaper device and does much the same  although trips off when the full 20
amps is drawn quite often. It has similar noises on several bands, which I
can live with but is about the same as the other on 160. I have not
attempted to add filters due to the limited success of the other. There is
little doubt the "proper" transformer PSU's I have are best   but where
weight is concerned the switch modes units are light and neat for the cost.
-  Ideal I guess for the VHF folk

  73   David G3SCD / VK3DBD
_____________________________________________________________________

Message-ID: <[hidden email]>


Iain, I use a Power Mite from Walters & Stanton when not in the shack - is
very quiet, both physically and RF wise
73 de M0XDF, K3 #174, P3 #108, KX3 #???

-_______________________________________________________________


On 10 Sep 2011, at 22:58, Iain Haywood wrote:

> Hi,
>
> Has anyone had any bad experiences using a K3 and a switch mode PSU?.
> The SEC-1223 looks great aware some can cause problems..
> They say 'Totally noise free', that's some claim..
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[ha4zd]

Alfatronix in UK does make very silent switch mode PS.  This is
excellent down to 500 kHz w/o any noise.  I use 9A version with the
K3/10. The 3A version is good only if you do not the second RX. They
have 20A version for 100W trx as well, but that one a bit expensive.

73, István


On 9/14/2011 11:03 PM, David Dunn wrote:

> Re:] Switch mode PSU
>
> I just read the comments and reply in the message below:
> I have both those PSU, the Sec 1223  is by far the oldest one. It has
> several" birdies"   best described as rather Raucous Crows, which get worse
> as the frequency goes lower. 160m is pretty poor.   I added several devices
> in attempts to quieten same, which was achieved to some degree.  It is
> acceptable on all but 160m,   where it appears in about 3 places across the
> band, (not always the same places)  The Waters and Stanton  Power Mite is
> cheaper device and does much the same  although trips off when the full 20
> amps is drawn quite often. It has similar noises on several bands, which I
> can live with but is about the same as the other on 160. I have not
> attempted to add filters due to the limited success of the other. There is
> little doubt the "proper" transformer PSU's I have are best   but where
> weight is concerned the switch modes units are light and neat for the cost.
> -  Ideal I guess for the VHF folk
>
>    73   David G3SCD / VK3DBD
> _____________________________________________________________________
>
> Message-ID:<[hidden email]>
>
>
> Iain, I use a Power Mite from Walters&  Stanton when not in the shack - is
> very quiet, both physically and RF wise
> 73 de M0XDF, K3 #174, P3 #108, KX3 #???
>
> -_______________________________________________________________
>
>
> On 10 Sep 2011, at 22:58, Iain Haywood wrote:
>
>> Hi,
>>
>> Has anyone had any bad experiences using a K3 and a switch mode PSU?.
>> The SEC-1223 looks great aware some can cause problems..
>> They say 'Totally noise free', that's some claim..
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html

______________________________________________________________
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