Wednesday, December 4, 2019

30m FT8

A shot from PSK reporter of my signal FT8 signal on 30m. No problem getting into Europe and I am very pleased with my Endfed antenna set up at only 20 feet off the ground. The power is set to 30 watts. My go-to software for FT8 is JTDX alongside JT-Alert. I am also running the Win4icom suite as well as AClog software.

Sunday, December 1, 2019

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

Saturday, November 30, 2019

The Astron SS-30M power supply.


I picked up the new power supply last week on Friday from the post office just in time for the CQ WW CW DX contest. The power supply I ended up choosing was the Astron 30 amp switching power supply. Yes I wandered away from the linear power supplies and into the dark side of the switching power supplies. The supply had very good reviews and now that I am on a fixed budget the linear supplies were just a bit to high for the budget. I have been using this supply for over a week now and am very pleased with it. There is no"hash" from this supply that I have read about online with other switching supplies. I have used it in the CW contest and also this week on FT8 and it has not heated up at all. After repairing the Astron RS20 I decided to keep it as a back up supply just in case the new supply in the future lets me down.....BUT when I do use it I will keep its duty cycle in line to what it has been designed to handle and not what I was putting it through.

Wednesday, November 27, 2019

The Astron RS20-M repairs completed

Repaired and working
The repairs to the Astron RS-20M are complete and the power supply I am happy to say is back up and running. In the process of sourcing out the parts that I needed a reader of my blog gave me a glowing recommendation of Digi-Key Electronics. I am very glad that he gave me the heads up regarding this company. When I went to the site you have the option of chatting live with an agent if you have any questions. I took advantage of this several times as I wanted to make sure I was choosing the correct items. The order was placed with them and immediately I received a
Negative to case ground 
Confirmation email regarding the payment going through. Within an hour another email was sent informing me my items had been shipped along with a tracking number. My dealings with Digi-Key was outstanding, I had recently dealt with an Amateur radio store up  this way (when ordering my new Astron power supply). The only email I was sent informed me my order had been processed and that was it. I wondered if just the payment went through, if the order had been picked and or if the order had been shipped? I ended up calling them to see if it had been shipped I asked when I may expect it to arrive, so I would make sure I was home as it needed a signature. The person on the phone sounded very put out as it required them to do some digging. They did return to the phone informing me it had been shipped and should be here by Friday. When I asked for the tracking number I was told it was not store policy to give out this information?? The power supply ended up coming on Thursday, and I was not home which required me to make a trip to the post office on Friday to sign and pick it up. Let me get off my soapbox and get back to the power supply repairs.
I found this great site online regarding Astron power supply trouble shooting and repairs. This document really helped me with the trouble shooting and eventual repair of the power supply. There was another online article I came across regarding how Astron now and then has the negative terminal grounded to the case of the supply.
New bridge rectifier
The part that I had to replace was the Bridge rectifier but I also ordered some heat sink compound as this was used between the Astron case and bridge rectifier. I also removed the two pass transistors and replaced the heat sink compound there as well. As mentioned above some Astron power supplies have a wire going from the negative terminal to the case ground. I read the information (seem link above) regarding Astron sometimes grounding the negative terminal to the case of the power supply. My power supply was wired this way and I decided to remove this jumper wire, if you have the same situation with your Astron supply read the article via the provided link above and make your own decision.
With the new bridge rectifier installed and wires re-soldered, the pass transistors back in place and finally I did remove one connection of the Varistor to test it (tested ok) I had to also re-solder that back on as well. It was now time for the smoke test.......and I was pleased that no smoke was found and the power supply is now working without issue. I did connect it to the Icom 7610, adjusted the power to 50 watts and the power supply successfully passed the load test as well. This power supply is under sized for the Icom 7610, I now have a new Astron power supply that is sized correctly. I am now wondering if I should keep this supply or sell it?
Passed load test