” TIP CAS. I ca IN ICAO. PвKE. | 39A. LM CR3 |. 3 A4. | IN 1 tci +. CI01 +. R8. 3 K. 10v. SCRI I. Astron Observations. Longevity. Family of RS supplies – all the same design Astron RSM Astron is inconsistent – some do, and some don’t. Don’t rely on . Here is an annotated schematic of the Astron RSM detailing the workings of the various parts of the Astron circuit. The annotations were originally written in.
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Also notice that, rs35a in the white heat sink compound on the left, there appears to be a short piece of metal that had been trimmed off of one of those rods that is used to connect the parallel rectifiers. It is a traditional linear power supply, consisting of a big, heavy transformer operating at 60Hz, a rectifier, a filter capacitor, a linear regulator, and a bank of linear pass transistors.
Manuaal copyright infringement is intended. That website, as its name suggests, is oriented toward repeater use.
A look at the Astron RS-35A
The linear regulator and pass transistors smooth this out to a well-regulated With the mod I’ve only had the fan go to full speed i. August 14, Both are based on the popular LM voltage regulator integrated circuit.
Some of the Slim-Line supplies have a cable and connector appropriate for the radio to which it would normally power. When I opened the supply up and took a look inside, I found a few things that seemed a bit ugly to me, even though they would probably work well enough for a long period of time on a supply that is used in a fixed location, as this one is likely to be used.
Keeping the power supply in a separate unit from the radio makes the radio lighter and cheaper, and allows the heat from the power supply to stay far away from the radio. It also allows a radio to operate easily off of 12V lead-acid batteries, or automotive electrical systems.
He scanned then redrew and corrected the schematic so it matched the actual unit; this drawing can be found as a PDF file below. Maybe I need to try someone else there.
July 31, Supplies rated for 12A or less RS and under usually have 3-way binding posts on the rear for output terminals.
A look at the Astron RSA – AG6QR
As more current is drawn from manuak supply, more heat is produced. If you desire an adjustable dropout, add a 30k trim pot to the board in series with the existing 62k resistor.
For example, the RSA can deliver up to 35 amps at If you find one somewhere else that we don’t have, we’d appreciate a scan. A trailing “L” indicates there’s a cigarette Lighter socket on the front. Changing R17 to 91k will move the Low Loltage Qstron to Xstron of mains entrance and fuse. These have room for a two-way radio to be mounted inside the cabinet.
April 27, All Rights Reserved, including that of paper and web publication elsewhere.
N5PA Website – RSA Power Supply
It appears you have a handle on operating the unit, even to the point of correcting meter errors. I found that site and referenced it above also. Anyone have a copy or know where I could obtain it?
Close up of the soldering on the back of one of the pass transistors. The right side heatsink has the fan thermostat mounted to it. Two white LEDs with a single dropping resistor is all that is janual. I recently purchased the venerable Astron RSA, one of the most popular amateur radio power supplies.
Astron RS35A 35 Amp Power Supply
The continuous current is somewhere between 50 and 80 percent of the peak current. Since there are significant voltages exposed on those terminals, things ought to be mechanically secured.
They’ll even ship it to you and let you remit payment after you receive it. At lower output voltages, there’s more voltage across the transistors, so they get much hotter. Make sure you print the mod sheet and tuck it inside mxnual supply for the next guy. A conversion rd-35a of Motorola to Astron model numbers can be found here.
Astron sent me a manual in e-mail. The absolute maximum current where foldback limiting occurs is usually 10 to 30 percent above the peak current rating. The only other related thread I found so far is: Before installing this mod simply running my PII on receive was enough to turn asttron the fan every 5 minutes or so. A trailing “M” indicates front panel Meters.
As for illuminating the meter, that is a piece of cake. Another way of saying it is that this is a ground inverting unit.
Send them to the maintainer listed at the top of this page you will be credited unless you tell us not to. I provided my serial number and they were able to tell me it was manufactured in May serial: Each one is dated on the individual drawing.