Potential Astron power supply failure solved!


One of my blog readers informed me regarding the Astron linear power supply that the outer case on the pass transistors at the rear of the supply are live with about 24 volts.  These pass transistors are isolated from the case and the heat sink so the potential is there to inadvertently via a PL259 connector, USB cable or any other conducting item at the rear of your setup to short the pass transistor and destroy them.  This morning I once again was searching the internet to see if anyone had devised a solution for this very issue. I came across a web page . This individual has the RS-35A power supply and came up with a great solution using a 3D printer. Now I am not at all up on the whole 3D printer thing but click on the link  above (web page) and have a look at the pictures they posted. The covers look great and are very professional looking. It would look to me the plans are available to those who have access to a 3D printer to produce the guards them self.  I would really like a set of these for my RS-25 but just short on the 3D printer part of things.
To my fellow bloggers have a look at the above link and do post any 3D printer info you may have as well.

As a side note below are some links to great information regarding Astron power supplies.

http://www.wb1gof.org/files/AstronPDF.pdf

http://www.repeater-builder.com/astron/pdf/astron-troubleshooting.pdf

http://www.repeater-builder.com/astron/astron-repair/astron-repair.html

https://www.ecse.rpi.edu/courses/CStudio/ham_radio_docs/astron-repair-index.htm
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

12 Responses to “Potential Astron power supply failure solved!”

  • Ron N8WCR:

    I found this a while ago and printed them out. Works great, especially if you have them in black, blends right in. Since I always have cables and wires hanging down the back of the desk I thought these were a must have.

  • Dave KB0CVX:

    I’ve been using Thermalloy transistor covers for close to 40 years. MUCH easier than messing around with the 3D printing business.

    One source here:

    https://www.westfloridacomponents.com/G619APH07/TO3+Transistor+Insulating+Cover+Aavid+Thermalloy+8903VBG.html

  • Brian AB9ZI:

    Mike,
    Try public libraries for 3D printers for public use! Those that have them just charge a bit for the materials.

  • Bob N8SQT:

    There are also plenty of 3D printing services online, and probably in your area as well.

  • Mike ve9kk:

    Good evening Ron and thanks for taking the time to leave a comment, first off I checked out your page on QRZ.COM and nice 3 monitor setup! I just ran across this site that has the protectors and it’s good to read that you downloaded and printed via a 3D printer and that they are serving you well.
    73 and have a good upcoming week.
    Mike
    VE9KK

  • Mike ve9kk:

    Hello Brian very nice to hear from you, well up this way in New Brunswick, 3D printers are nowhere to be found in libraries. But another blog reader left a comment here informing me that I could go online and look for a 3D printing service.
    Thanks, Brian for stopping by and commenting.
    73,
    Mike
    VE9KK

  • Mike ve9kk:

    Good evening Bob from New Brunswick, I never even thought about going online and sourcing it this way. My only issue would be that the online 3D plans are for the Astron RS-35 and I have the Astron RS-25 and the specs could be different……..but having said that it sure does give me a start to move in the right direction.
    Bob have a great upcoming week and thanks for stopping by the blog and giving it a read.
    73,
    Mike
    VE9KK

  • jeff n1kdo:

    You can buy transistor covers for the TO-3 devices on these power supplies, for instance, this: https://www.digikey.com/product-detail/en/keystone-electronics/4634/36-4634-ND/316224

    Not expensive.

    Jeff n1kdo

  • Mike ve9kk:

    Good afternoon Jeff thanks for taking the time to comment and leaving a link, I was just wondering if these caps since they have no ventilation would the transistors overheat?
    Thanks
    Mike
    VE9KK

  • Mike ve9kk:

    Good afternoon Lowell, very nice to hear from today and yes they are cheaper but my question is the same as it was for Jeff……with covering the transistors in plastic with no ventilation would this cause them to heat up?
    Have a good week Lowell
    73,
    Mike
    VE9KK

  • Mike ve9kk:

    Good evening Dave, very sorry missed your comment entirely………it happens with old age if you have been using them on Astron supplies and had no issues then the subject is closed regarding hunting out a 3D printed solution. Thanks for the info and I am going to order 2 of them so look after my Astron supply.
    73
    Have a great rest of the week
    Mike
    VE9KK

Leave a Comment

Subscribe FREE to AmateurRadio.com's
Amateur Radio Newsletter
News, Opinion, Giveaways & More!

E-mail 
Join over 7,000 subscribers!
We never share your e-mail address.



Also available via RSS feed, Twitter, and Facebook.


Subscribe FREE to AmateurRadio.com's
Amateur Radio Newsletter

 
We never share your e-mail address.

Please support our generous sponsors who make AmateurRadio.com possible:

KB3IFH QSL Cards

Hip Ham Shirts

Georgia Copper
Expert Linears

morseDX

Ni4L Antennas

Ham-Cram
R&L Electronics

Do you like to write?
Interesting project to share?
Helpful tips and ideas for other hams?

Submit an article and we will review it for publication on AmateurRadio.com!

Have a ham radio product or service?
Consider advertising on our site.

Are you a reporter covering ham radio?
Find ham radio experts for your story.

How to Set Up a Ham Radio Blog
Get started in less than 15 minutes!


  • Matt W1MST, Managing Editor




Sign up for our free
Amateur Radio Newsletter

Enter your e-mail address: