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| Reviews Summary for Johnson Viking 500 |
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Reviews: 3
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Average rating: 5.0/5
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MSRP: $795 in 1964
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Description: 500-600 watt input, AM CW transmitter. 80-10 meters
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Product is not in production.
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More info: http://
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write your own review of the Johnson Viking 500.
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KG8LB
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Rating: 5/5
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Aug 19, 2009 13:06
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Well worth the hunt
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Time owned: more than 12 months
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I traded a real clean T-368 for my Johnson 500 about 15 years ago. So far no regrets. Upon setting the radio up for the first time I came upon a small, oft reported problem. On modulation peaks at times there would be a "pop" at the rear apron of the RF deck coincidental with a blown HV fuse. Upon investigation it was discovered the modulated HV pin jack on the rear apron had a fracture at the root of the thread where it passed thru the chassis apron. I ordered a fresh set and replaced all of them. I understand many people have felt the need to replace these connectors with more robust types but if properly torqued and handled the stock pin lacks are quite adequate, at least from my experience. A close friend and at that time local 500 owner also had a 500. He had a chronic loud "pop" but in his case it would occur intermittently when he unkeyed. While this was going on, he managed to lose an HV transformer, a plate choke as well as his mod transformer in fairly short order. About that time mine took to snapping when unkeyed. Fearing the snapping and damaged iron were related in some way I got out the schematic and investigated. The original control circuitry included a time delay to hold over the antenna for a brief time when unkeyed. I surmised this was to allow the antenna to drain off flyback energy induced in the tank circuit when the high voltage was removed (maybe ?) In my case at least the time delay relay was not doing the delay thing. I came up with a simpler time delay circuit using a cap and diode to take the place of the factory setup. That completely solved the problem for me. I then related my findings to the other owner. He employed the same technique in his 500 with the same result, no more snap !
About 5 years ago I finally felt a bit guilty for operating the 500 on it's 1961 dated electrolytics. It wound up with a fresh set of Mallory caps supplied by the Harbaugh folks.
Still using the same old 4-250 that came in the TX and some previous owner had installed a pair of 811A tubes in the modulator that are about 30 years apart in age.Good output to the antenna and still get full, rich modulation. The audio has been very conservatively modded and I always get excellent audio reports . Over the years I have used many different microphones, D-104, EV 630, EV 664, EV RE-20 and presently an old Altec ribbon model 670B. They all work quite well.
Operating the Five Hundred is a pleasure. The drive tuning tracks with the VFO so a QSY is mostly spot, dip and load of course checking the grid drive level but no need to tune the grid.
I like the concept of the heavy, not so handsome power supply modulator on the floor and the good looking, fairly light main unit on the table top. The Five Hundred is a very likeable transmitter and has been in the shack longer than any other piece of ham equipment I own....aside from the Thompson levering straight key that was given to me almost 50 years ago by the original W8OT, Ralph Keppler.
The Five Hundred remains my favorite boat anchor transmitter. I would still trade a T-368 off to get a Five Hundred !
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WD8KDG
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Rating: 5/5
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Jun 20, 2006 11:45
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Great 500 watt AM Boat Anchor
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Time owned: more than 12 months
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This review starts with a small history lesson. E.F.Johnson produced 865 Viking 500 transmitters from 1957 until 1964. If you are fortunate to own one or are about to restore a 500, do no harm, the large parts are getting hard to find.
I'll quote from a 1960's ARRL Handbook the advertisement: VIKING "FIVE HUNDRED" TRANMITTER-Rated a full 600 watts CW...500 watts phone and SSB. (P.E.P. with auxiliary SSB exciter.) All exciter stages ganged to VFO tuning. Two compact units. RF unit small enough to place on your operating desk beside receiver--power supply/modulator unit may be placed in any convenient location. Crystal or built-in VFO control--instant bandswitching 80 through 10 meters--TVI suppressed--high gain push-to-talk audio system--low level audio clipping. Pi-network output circuit with silver-plated final tank coil will load virtually any antenna system. With tubes, less crystals, key, and microphone. Dimensions: RF Unit--21" X 11-5/8" X 16-1/2". Power Supply--20-3/8" X 15-3/4" X 10-7/8". Total Shipping Weight:200 lbs.
Cat. No. 240-500-1..Kit......Amateur Net $749.50
Cat. No. 240-500-2..Wired & Tested.......$949.50
One of these boatanchors followed me home two years ago. At the time it had been setting for 15 years unused, all the big pieces were there. But, the interconnecting cables and key were missing. Then, there were the usual issues with past repairs and modifications.
Two months later after checking every resistor, capacitor, removing modifications, etc., I was finally able to turn on the HV to the 4-400A Power Amplifier and 811A modulators. "Real Radios Glow In The Dark", the efforts of restoration paid off well. This is the time to replace every electrolytic capacitor, paper capacitor, and off value resistor in both units. I'll repeat, "The large parts are getting hard to find". Now is the time to locate parts that are worn out or are about to fail. They WILL take other expensive items with them when they do! The beast has been on the air for two years now, with good AM audio reports and no problems.
The Viking 500 has two small faults: One is the Cherynobal resistor in the VFO. Rangers and Valiants suffer the same affliction. Johnson fans have replace this 18K 2W resistor with a 5W version. Second item is the tip plugs and tip jacks used to connect B+, modulated B+, and screen voltage between the PS/Modulator and RF deck. Some have replaced this type of connector with BNC connectors or insulated HV feed throughs. I've encountered zero problems with the tip plugs/jacks because of taking the time to read the manual. Use cable straps to prevent the tip plugs from backing out of the jacks. This will also prevent strain from breaking the small diameter tip plugs.
Speaking of manuals, Johnson, as usual, wrote a great one for the Viking 500. The descriptions of proper operation and trouble shooting make this a must read for anyone owning or repairing this transmitter. Following the manual through, page by page, I was able to start at the low voltage/rf stages and work my way through the power supply/modulator and rf deck without blowing a single fuse.
If you are the original owner, the terminal covers might be still in the junk box. Most owners threw the covers in the trash years ago. I've never hear of anyone wanting to use them, seems they just get in the way of connecting antenna relays and receiver muting.
To date my Viking 500 has zero modifications, I've left the audio stock. The wider bandwidth and bass audio will not punch through QRM as well as the stock audio. The only thing required is to adjust the clipping potentiometer for zero clipping. A 0.01uF 6KV ceramic capacitor has been added to the secondary of the modulation transformer to provide modulated B+ to the horizontal plates of an oscilloscope to view a trapezoidal pattern. A standard RF pickup on the output of the transmitter will provide feed to the vertical plates to view a waveform pattern.
Operating an AM transmitter without an oscilloscope is like driving a car at night without headlights.
73's & have fun
wd8kdg
Craig
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WB5MHA
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Rating: 5/5
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May 14, 2006 16:30
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THE BEST!
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Time owned: more than 12 months
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A 500 watt input hf AM transmitter that includes 11 meters. This is as good as it gets!
Although the statute of limitations has long since run out on 11 meter mischief done in 1963-64 I remain mute on the subject. Instead let me relate to my Sunday morning skeds with KV4AA and TI2LA, 21mHz AM.
At age 14 I was informed that the minister of the Lutheran Church about 200 yards from our house had called and asked if I could stay off the air during his survices. It seems that my voice saying "TI2LA KV4AA this is WA9BYR on sked" overwhelmed the audio system at his church every Sunday AM during survices. According to the minister my audio was Q5 and perfectly modulated. Perhaps 100 plus loyal Lutherans thought I was the voice of God, at least for a few seconds.
I still remember the beautiful glow of the mercury vapor tubes which are now considered serial killers by the EPA.
The memory of the huge dial with the amber VFO frequencies will always bring tears to my Social Security eligible eyes.
The key! Not a cw key. I'm talking about a real keyring type key that was necessary to turn the monster on. It was like an ignition key socket right in the middle of the front panel.
The Viking 500 came in two parts; the rf unit that sat on the desk and the power supply with the art deco/disco mercury vapor tubes. The power supply weighs one million pounds. Take my word for it.
Every time I find one for sale I make the blind threat to buy it. Every time I do my friends (hams from the 1960's) promise that if I do they will see to it that I am put in an institution where I can be watched.
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