Galaxy 5 mark 3 in-12dc-out in back of transceiver

[KD0PRL]

Since the power supply for the Galaxy is not working I would like to test the transceiver with a 12 volt battery.  Of course the battery has pos and neg. terminals but the back of the Galaxy has three jacks.  IN-12VoltDC-Out.   What two of the three do I use to connect ?   I had tried the origional power supply and it lights up but no voice with speaker. I have re-tubed the entire Galaxy and have replaced about 4 electryotic capacitors.  It did hum but now its quiet. Just a mild hiss.  By the way I will put a fuse in the circuit for safety I guess from the positive side of the battery.  I need an Elmer's help please.  Thank you   Al

[WB2WIK]

The Galaxy V MK III uses an external power supply, either an AC or a DC one.

If you don't have the external DC power supply, it doesn't matter what you connect to the rear panel RCA jacks, it's not going to power the transceiver!

The power cable from the power supply (AC or DC model) plugs into the 12-pin Cinch-Jones connector on the rear panel of the transceiver.  The little RCA phono jacks on the rear panel are for an external CW filter option: The CW filter has three connections, which are IN, OUT, and 12VDC which is used to power the option.  These are NOT used to power the transceiver.

[KD0PRL]

Thanks so much for the information!!!   My next question then is how do they use it mobile from a car battery in a car?   It does show a mobile installation in the owners manual.  The Cinch-Jones connection has to be involved then with the car battery?   Sure glad you gentleman are around to help us.     Al

[AD4U]

Manufacturers of tube rigs made mobile power supplies that used switching transistors to turn 12VDC from the car battery into a square wave or pulsating DC which was then fed into a power transformer with rectifier and filter caps.

Dick  AD4U

[W9GB]

How do they use it mobile from a car battery in a car?   It does show a mobile installation in the owners manual.  The Cinch-Jones connection has to be involved then with the car battery?   Sure glad you gentleman are around to help us.

Al --

You see this power supply technology on a regular basis (Inverters) used within APC UPS units on office and home computers.

The mobile DC power supplies connect to car battery with typical 2 large AWG wires (red/black) due to current (amps) draw.  The supply takes this DC input and outputs HV DC for the tube circuits (Cinch Jones Multi-pin plug), and some mfg. units even recreate AC (inverter).

This technology was VERY COMMON in 1940s - 1960s with vacuum tube radio equipment.
The 1970s was a transition period, with introduction of first all solid-state radios.  By the mid-1980s, solid-state using 13.8 V DC was common, with vacuum tube radio equipment production ending.

Technology advances, and understanding this progression is important for Boatanchor radio operation and repair.

[KD0PRL]

Thanks for all the information. I guess unless I find another Galaxy power supply that works I will put the Galaxy 5 on the shelf to admire.   Al

[AC5UP]

What AD4U said.

Wasn't uncommon in the 60's for a transceiver to be sold in two pieces... Rig and power supply sold separately. You bought the 12 VDC power supply or the 115 VAC power supply depending on your preference. If you really liked the radio you bought both power supplies so you could take it with you on vacation.

[WB2WIK]

Thanks for all the information. I guess unless I find another Galaxy power supply that works I will put the Galaxy 5 on the shelf to admire.   Al

The Galaxy AC power supply is very simple and very similar to those made for other similar rigs of the era (Swan, Heath, Drake, Hallicrafters, et al).  Should be easy to fix whatever's wrong with the power supply.  The most expensive part would be the transformer, and even those are available.