Happy new year and good evening fellow Ampers!
Recently I purchased a very nice looking low mileage Henry 8K Ultra
(230Volt-3ph). Serial number 65-4xx.
I knew beforehand that this one had a problem, that the load tuning stopped
at 7.5 and could not be tuned to 10(max) and that the driver was a
transceiver at 100 watts. However no one had investigated what was wrong so
it had just been sitting there for several years?
I also spoke with the guy who happened to be using the amp when the problem
occurred but he was unable to tell me what was wrong or give any description
of what happened. After a 1000 km journey in the back of a truck it arrived
before Christmas and me and a ham friend decided to carefully check first
the controller unit, everything was fine there, we put local power on the
unit and everything behaved fine. Next was opening the console for visual
inspection. Soon we found 3 fixed capacitors were loose so screws were
tightened and one missing screw was replaced (not found inside the
cabinet).At first my fear that there was something wrong with the big tube
roller inductor looked too pessimistic ?however a closer look revealed that
the grooved wheel shaft had fallen off and was resting at the roller
inductor floor.. I?ve seen comments on the web of Henry?s that if the roller
inductors are damaged?you?re stuck.. Big bucks gone--.end of story.
However we both think it can be repaired and we agree on trying. So
yesterday we concluded that the shaft hinges had most likely broken due to
getting brittle or due to extensive vibration during the long truck
transport.
These hinges consist of a pair of a flat curved spring approx. 3/16?wide x
0.01? thick x 2 ? long fixed at each end of the shaft. We tried replacing
them with the same size of flat brass however found it too soft and not with
enough spring back to ensure enough pressure/force on the wheel against the
inductor tube wall.
My guess is that Nichrome (80?) ribbon (flat) material could be a
replacement, however I am not sure so I ask for your advice. Also I hope you
can direct me to a source that sells it smaller quantities.
73 de LB2HG/AA4NX Harald
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