RAN Technology


 Posted By: Robert Nickels (ranickels)
Posted: 07/12/2021

Vintage Ham Radio 07/12/2021 

The Vector VR-50

last gasp from Swan/Atlas founder Herb Johnson


 

Most hams are aware that Herb Johnson W6QKI founded Swan in Benson Arizona to make single-band SSB transceivers and then moved his operation to Oceanside CA where Swan thrived throughout the 1960s.   Swan merged with Cubic Corporation in 1967, and Johnson managed Swan as its subsidiary until 1973. Johnson founded Atlas Radio in 1974, with the assistance of Southcom International founder Les Earnshaw ZL1AAX.   But what happened next?   Not much is know, but we do know he spearheaded the development of one more SSB project - the Vector VR-50.    Who actually designed and built it is unknown, but do know that Herb liked names that had significance to him, which is why Swan was named for his father, Sven, and Atlas was chosen as it was the name of the diesel engine in the 1924 motor boat skippered by his friend Don Gumpertz, K6OF.

Herb was an avid sailor, skippering a series of boats (all named Vector) in numerous long-distance races along the coast of California and Mexico. He was a longtime member of several San Diego yacht clubs and continued sailing, well into his seventies,   So given his history with small solid-state portable SSB transceivers and the many explorers and adventurers who used Atlas radios, combined with his love of sailing  it's not surprising that he named his last radio venture the Vector VR-50.

The amount of documentation avaialble on the VR-50 is minimal and doesn't (yet?) include a schematic, but it's designed to be easy to use and the existing units that have surfaced have been similarily configured, so were probably part of the same (one and only) production run. 

The RT unit is very small but the resemblance to a down-sized Atlas is unmistakeable.   It is rated for 50 watts PEP output and covers from 1.8 to 17 MHz continuous, based on which crystals are installed.   The radio has a split personality:  with the selector in the "HAM" position the channel switch provides up to 12 channels in the 160, 80, 40, and 20 meter bands with a VXO that provides 12 kHz spread on each channel.   The photos below show the frequencies installed in my VR-50.   Other than opening it up for photos I haven't done anything with the radio.  One experiement I'd like to try is to see if an 17 meter signal can make it through the filters.  I suspect it can but of course the WARC bands were not envisioned at the time it was designed.  I'm sure 60 meters would be usable by selecting the 40 meter BPF once it's determined how that's done. 

In the AUX position, up to 12 marine HF SSB channels may be selected.  In this case the VXO range is greatly reduced so it acts as a "clarifier" iin the receive mode only to comply with FCC regulations.   I'm sure the frequencies installed were what a sailor in the San Diego area in the mid 1960s would have used.

But the real interesting thing about the VR-50 is the way it's packaged.   The compact RT unit mounts to a hinged plate that folds flat for storage inside the Pelican-type waterproof case, or can be raised and locked into position for use where the controls are easily accessible.    Power is provided by a 12 volt gelcell which is continually charged by a solar panel mounted the the case lid.   Just pop the case up and a simple spring mechanism snaps into place to  hold the lid at a good angle for catching sunlight.   The company said that a day of sunshine would provide enough power for 2 hours of operation, based on 1/3 transmit, 2/3 receive duty cycle.   It can also be recharged from a 12 volt source.

Rounding out the complete package is a cut-down AT-271 whip antenna that attaches to a mount on the case and a manual antenna tuner that uses the meter in the radio for tuning.    The whip sections have been shortened so they could be stored diagonally inside the lid of the case, which also houses a speaker.   The whole package is very compact and well thought-out - you get the impression it was meant to be used in marine environments where it would be packed-up and stowed after use, and could be the last thing you'd grab in the event you had to deploy the lifeboat!   (The instructions note that "It floats!")

The only drawback is crystals nowadays.  I've tested mine with an external digital synthesizer but since there's not a lot of room or desire on my part to hack the thing up, and since it's equipped with usable ham band crystals, I've just left it as-is.   There's clearly room for modification if one desired.    I can say it's worked well with typically good Swan/Atlas audio on transmit and receive and a very usable power level from a portable rig.  Although gel cells aren't my first choice there are lots of alternatives today.

A handful of VR-50s are known to exist and more information or new owners are always welcome!

 

   

Crystal Replacement
Posted: 02/38/2024
Comments: 0
How good can a crummy receiver be?

Hundreds of different simple SDR receivers have been designed around Dan Tayloe's Quadrature Sampling Detector or QSD.   Mine add nothing to the state of the art, and in fact subtract things, as I like minimalist solutions and the QSD is right in that sweet spot.   Following the evolution of Tayloe's design I delete the resistors in series with the sample lines for inst...  READ MORE

Technical
Posted: 02/37/2024
Comments: 0
What's in a number (3253)?

The FST3253 dual four-to-one mux/demux IC has long been used as a "Tayloe Detector" or QSD (and QSE) in low-cost SDRs.   They provide incredible performance for such a simple circuit, converting RF to baseband IQ with low loss and the ultimate in simplicity. Unfortunately the original FST3253 part has become obsolete and while substitutes are available, this is where the...  READ MORE

Vintage Ham Radio
Posted: 02/32/2024
Comments: 0
The Stancor 10P Transmitter

There weren't really many commercial transmitters in the 1930s as most hams built their own.   But many of the ones that were offered came from the transformer companies who had two chances to profit.   First, from those who would buy the kit, and two, from those would would see it in the (free) booklets the companies provided to their distributors who would then sell the iron to ham...  READ MORE

Vintage Ham Radio
Posted: 12/355/2023
Comments: 0
The Care and Feeding of the EF Johnson Courier amplifier

The EF Johnson "Courier" is a grid-driven amplifier using two 811A tubes.   Switching is provided for operating in either class C for CW or as a class B linear amplifier for AM or SSB.   Rated power is 500 watts input for CW, 500 watts PEP input for SSB, and 200 watts input for double-sideband AM with carrier.    Since all amateur power levels were meas...  READ MORE

Historic
Posted: 11/329/2023
Comments: 0
TV Duplexer

Some things are interesting, even if totally useless nowadays.   Such is the case with the Philco 426-3034 Crossover Kit for UHF TV.   What the heck is that? Well, back in the late 50s,  UHF television stations operating on channels 14-83 started to appear in many areas of the US where viewers had a VHF-only TV antenna, and in many cases an externa UHF converter was...  READ MORE

Crystal Replacement
Posted: 11/327/2023
Comments: 0
Replacing failed crystals

For decades, quartz crystals were used everywhere a stable frequency source was needed, even in some applications that depended on overtone (harmonic) behavior into the VHF range.   These crystals were less stable and more dependent on circuit parameters that fundamental types and thus more problematic.    Such was the case with the 94 MHz crystal in the 2 meter converter ...  READ MORE

Historic
Posted: 11/315/2023
Comments: 0
My Own Ham Radio Story by W9RAN

Everyone has a story of how they got involved in ham radio - this is mine.   It started much earlier, including receiving a Knight Kit Span Master shortwave radio for Christmas in about 1963, at age 12.   I'll never forget the night my dad and I finished building it and I wanted to try it out.   It came with a 50 ft. antenna which was still coiled up - but ...  READ MORE

Technical
Posted: 09/267/2023
Comments: 0
Hot to simulate vacuum tubes in LTSpice

LTSice is a powerful simulation tool that is provided free by Linear Technology Corp.   It comes with a complete library of passive and common analog solid-state components but if you want to use it to simulate vacuum tubes, it doesen't work as-is.    Even though triode and pentode symbols can be found in the "Misc" folder, they are just schematic symbols and...  READ MORE

Friends Remembered
Posted: 07/208/2023
Comments: 0
Merv Schweigert, K9FD (SK)

Comments from Robert Nickels W9RAN,  July 27, 2023: There is nothing worse for a ham radio operator than to see a beloved friends callsign with the letters "SK" behind them.   Yet sadly, that's what happened on July 23, 2023, when I learned of the passsing of Merv Schweigert, K9FD.     While many of our ham radio interests were different - Me...  READ MORE

Vintage Ham Radio
Posted: 01/19/2023
Comments: 0
"Winter Projects"

I know many of us who enjoy restoring and repairing vintage gear look forward to winter when there is less competition for time and energy, and a chance to really make a dent in our "to be fixed" piles.    A couple of years ago I set time aside for "Heathkit Singlebander Week" and went through every one of them I had, with the result that they're all working ...  READ MORE