[Amps] Astron Power Supply replies

[Roger (K8RI)]

Check your voltage "TO" the pass transistors.  If it's high the 
transistors will run hot.  IIRC the VS and RS use the sane control 
circuit, but it's been quite a while since I had one apart.

Please NOTE the Green wire is not neutral!  It is a true ground, or 
"earth" connection.  Never, ever treat it as neutral.  Your power cord 
should also have a green.ground / earth AND a neutral (White) wire.   If 
it is one of the newer modular cords, it goes to the round pin below the 
hot (larger blade) and neutral (smaller blade)  .  I don't know if the 
newer Astrons are using those cords, or are still using direct wired 
power cords.

73

Roger (K8RI)


On 1/28/2015 9:50 PM, Gary Smith wrote:
> Gentlemen,
>
> Thank you all so much for the replies regarding upgrades, suggestions
> and green wire dealings with my two Astron power supplies. The only
> reason I asked that here was the mention of the green neutral being
> left in a floating condition on at least some of the Astron PS. I
> need to repair the one that is Kaput and am looking around for a
> LM723 around here as the links mention that to be a common culprit,
> I've used them before in several projects and probably have several
> gathering dust in an old Radio Shack package. If not, I see them
> listed quite inexpensively on ebay and will pick up several for
> future issues I may encounter.
>
> The four 2N3771 transistors really do run hot on the VS-35M, can't
> say I touched them on the RS-35M but surely they are the same, the
> circuit between the two PS are very similar. I'm assuming I can use
> any off the shelf 2N3771 & the .05 5W wirewounds will balance them
> fairly. On the PS I made some years back I used 3055's and I have
> several of them unused, would these be more rugged or should I stick
> with the 3771 as it comes with?
>
> Mention was made of Arctic Silver; I have some Arctic Silver 5 & some
> of their Ceramique which I too used in overclocking computers. I can
> certainly remove & replace the heat sink compound with this, not a
> big job and using it did lower my core temps on the computer
> processor.
>
> I really appreciate the links and help.
>
> Thanks & 73,
>
> Gary
> KA1J
>
> ---
> This email has been checked for viruses by Avast antivirus software.
> http://www.avast.com
>
> _______________________________________________
> Amps mailing list
> Amps at contesting.com
> http://lists.contesting.com/mailman/listinfo/amps
>
>


---
This email has been checked for viruses by Avast antivirus software.
http://www.avast.com