Speed key tests

 

1953 Presentation, 1940 Les Logan 515, 1914 Vibroplex Original

Pictured above left to right, 1953 Vibro Presentation, 1940 Les Logan 515, 1914 Vibro Orig

I have around 50 speed keys of all years and makes & have always wanted to find the time to test the keys in order to select which key is capable of producing the best all around code. The best would be the one that produces crisp clean dots over all speed ranges and allows sending effortless code that seems to flow off the finger pieces.

During the fine tuning process, I equipped the keys with a speed control device that allows fast speed changes from below 18wpm to over 30wpm.


The first 3 keys I tested, I knew already produced fairly decent code to begin with.

1. 1953 Vibroplex Presentation
2. 1940 Les Logan 515 -- which has been modified with a better damper using 3m double backed tape. I had given up on this Les Logan due to dot stutter problems, but after using the 3m double backed tape as the damper material (instead of the metal damper wheel), it solved the dot stutter difficulty.
3. 1914 Vibroplex Original. Someone had taken a grinding wheel to the main spring on the 1914 key in order to slow down the dots. At first I thought the key had been ruined but it proved to make really decent code once fine tuned properly.
When fine tuning each key, all seemed to make very good code. But when you have all 3 keys on the desk at the same time, you soon find one key that is best.
And in this case I was amazed that the Les Logan 515 had the best low to high speed
crisp dots. And it was well balanced with both good dashes which match the dots ----as the code seemed to flow off the finger pieces. With a fairly close dot contact spacing of less than 1/16".
That dosnt mean all Les Logan 515's are going to be equally as good. There was a wide variation in main springs used from year to year. The small based Les Logan keys I have come across all tended to have the dot stutter problem.
The 1914 Original with the modified main spring produced good quality dots --- fairly close to the Les Logan. If I had taken the time to apply the 3m damping material on the 1914 key, it would have probably been very close to the Les Logan.

The Vibroplex Gold Presentation did produce very good code. I've tested around 10 Presentation keys over the last 10 years and have found a wide variation in the code they can produce -- due to the different types of main springs used. From 1949 until today, there is a wide variation in the quality of code produced by the Presentation keys due to the variation in main springs.
I'll be posting more speed keys tests as time permits. Mainly to see if I can find a key from the 1920's or one from around 1916 that might be as good or better. For some reason Vibroplex started using longer main springs in the 1920's. Probably in an attempt to allow adjusting for slow speeds using the same amount of weight on the dot arm. The key examples I have here from before 1920, tended to have shorter main springs. And that's probably why some of them produce very crisp dots. More on that later as I test more keys.



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