[Elecraft] K-Line Addition - DC Power Supply (Suggestion)

[hawley, charles j jr]

The Astron supplies usually have a crowbar on the output which shorts the output if the voltage rises above 15 Volts.

Sent from my iPad

On Sep 18, 2012, at 5:51 PM, "Vic, K2VCO" <k2vco.vic at gmail.com> wrote:

> I've fixed two Astrons for friends. One had a burned-out IC and the 
> other had a damaged board where the capacitor mounting screws had 
> loosened and generated heat. Both failed without producing overvoltage.
> 
> I have one that I've been using for perhaps 15 years with no problems.
> 
> On 9/18/12 2:14 PM, Ron D'Eau Claire wrote:
>> I guess it depends upon which Astron model you are working with. I've worked
>> with a great many RS and RM Astron supplies in Ham and Commercial systems
>> over the years and have never encountered one that made more than a very,
>> very quiet hum.
>> 
>> I'm not sure what you mean about the regulator not being "quiet". The LM723
>> is a simple linear I.C.; no switching noise and no acoustical noise.
>> 
>> The popular RS and RM series have both automatic over-voltage and
>> over-current shut-down that protects both the power supply and any equipment
>> connected to it.
>> 
>> In decades of use working with a great number of Astron supplies - many of
>> which are in 24/7 service operating commercial equipment - I've yet to see a
>> regulator failure - or any Astron failure for that matter. I'm not
>> suggesting that they won't fail, but I've yet to see it happen in,
>> conservatively, tens of thousands of operating hours.
>> 
>> My station Astron resides on a shelf out of the way under the operating
>> table so having a matching appearance with the rest of the K-line is not an
>> issue for me.
>> 
>> 73, Ron AC7AC
>> 
>> 
>> 
>> -----Original Message-----
>> 
>> 
>> Being linear regulators, the Astron supplies are probably pretty RF quiet,
>> but for what they cost they are big and can be acoustically noisy (I have
>> heard several buzzing transformers), not to mention containing antiquated
>> circuitry.  LM723 regulators are not the quietest nor most stable linear reg
>> ICs available these days, and have limited regulation bandwidth in stable
>> implementations.  Considering these factors i have been reticent to buy one.
>> 
>> I bet Elecraft can outdo what is available in a pretty little matching
>> package.
>> 
>> Howie - WA4PSC
> 
> 
> -- 
> Vic, K2VCO
> Fresno CA
> http://www.qsl.net/k2vco/
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