Astron PS mods

I’ve been pondering some modifications to make to my Astron power supply. The first mod I considered was replacing the nut/bolt terminals with Anderson power pole connectors, but it looks like that will require replacing some wiring and what appears to be additional filtering components which I think I’d rather not do in case I mess things up. Plus I’d also have to square out the round holes for the power pole terminals. I think I’ll just make up some pigtails with power pole connectors instead.

Found a fair bit of info and interesting looking mods to Astron power supplies at the Repeater Builder site that I might try. The in-rush current reducer mod looks simple enough and while mine has never tripped the breaker when I flip the power switch, it seems like a good idea to have in place.

I think it would also be neat to have a volt and current meter on the PS to monitor the output. There’s plenty of room on the front panel of the PS for meters, but my metal working tools and skills are limited and I’m not sure I’d be able to do a proper job yet. I think the easiest way for me to add the meters is make a separate enclosure or panel for them that will sit on top of the PS. That should be easy enough to do.

One interesting thing that I noted while browsing the Astron part of the Repeater Builder site is that all of the schematics for the RS-35M/RS-35A they have show only one large 2.2 mF filtering capacitor while there are two in my PS. Don’t know if that’s an addition to newer models, or if it was someone else’s mod.

After taking another look at the first pictures I took, it looks like there may already be a thermistor (the red thing that I think looks like a thermistor anyway) added in the circuit.

Think I’ll open it up again and have a closer look at what’s inside.

Power supply!

An Astron RS-35A power supply is my latest acquisition. Saw it on ebay for a pretty decent price, and after a few days of watching it, I thought I’d put a bid on it fully expecting someone to come in at the last minute and snipe me.

Well, that didn’t happen so now I have a big beast of a linear power supply that puts out 13.7V and peak current of 35A (“25A continuous”) for less than half of what one costs new. My original plan was to use it for what ever radio I ended up buying, but we’ll be putting Connie’s radio and its power supply into the office/ham shack so this one will probably sit out on the workbench and supply power to my other projects, maybe a second radio if we end up getting one.

Except for a dinged up corner and a broken foot (probably during transport) it’s physically in good shape. After plugging the unit in, flipping the power switch brings the beast to life with an intimidating but satisfying “chunk” from the transformer and the hum of electricity.

The power terminals are these bare exposed bolts with nuts to hold any wires on. I don’t really like the thought of exposed power terminals, so I think I’ll look into replacing them with some Anderson power poles.