EFJ Viking 500 Power Supply Project - RT's Radio Home Page
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EFJ Viking 500 Power Supply Project
Amateur Radio > Vintage Transmitters
Background:
The EF Johnson Viking 500 AM/CW transmitter was manufactured as a set of two major components, the Desktop RF Deck and the remote Power Supply/Modulator unit. These two units being connected together by plug-in cables. The separate units were necessary since power supply itself weighs around 120 pounds, while the RF deck weighs around 65 pounds.
Manufacture of the Viking 500 ended in 1964. Over the years, AM operation was superseded by Single Sideband (SSB) operation, so the older AM rigs fell out of favor and were often relegated to the garage or other storage area. When the owner passes away, the family members are completely unaware that the big, heavy unmarked power supply is a necessary component serving the RF deck, so many of these were sold off separately or sadly, went to the landfill.
The "Viking 500 #2" RF deck detailed elsewhere on this site was separated from its power supply at some point in history. The RF deck is now operational, so the construction of the new power supply/modulator unit is coming soon and will be detailed below.
The New Power Supply:
This is a power supply chassis from a Johnson Invader 2000. It was intended to be used as the basis for the Viking Five Hundred #2; however, extensive modifications would have been required.
Chuck, K1TLI reached out to hams who needed a new power supply chassis for orphaned 500 RF Decks. I committed to buy if he could produce them at a reasonable cost. Several other hams committed, and after a few months Chuck came through with a nice product.
The layout must have taken considerable time and effort. The machine work on the chassis is clean, and the nickel plating is well done. The original Johnson chassis was polished to a mirror finish prior to plating; this new chassis was not. Polishing would have likely added significant labor cost to the chassis, so it was best to skip that feature. A few more Viking Five Hundreds may have been saved due to the making of these new chassis; thank you Chuck!
Here is a link to Chuck's website: https://johnsonradioresto.com/home-page He does very nice work.
Another view of the new chassis.