>Gas tubes v. solid state regulators:
>
>I am always suspicious of an electronic device that hides the electron
>flow. When the VR tube glows, you know it is doing something.
* I have seen gas regulators which glowed but did not regulate.
>That is not
>the case with solid state regulators. The same problem applies to ceramic
>tubes. You cannot see if they are on.
>
>The best of all worlds was the wonderful old 1625 in the ARC-5. I could
>tune them up by tuning for minimum blue gas.
* the blue glow was usually florescence on the glass - which means it
was caused by electrons colliding with the fluxing agent in the glass
recipe.
>That was important because I
>had spent my $3.95 plus shipping for the ARC-5 and had not learned yet that
>a pilot lamp could be substituted for a meter. Later, after acquiring a VR
>tube, I learned that it could be put in an RF field and used for tuning
>just by holding it near the plate. And, then a friend told me that a
>fluorescent lamp could be placed at the end of the long wire to allow your
>ham neighbor to see when you are on the air.
>
>Solid state devices are fine - but they do not glow.
>
* I have seen them glow. It was not good news,
>I only wish they had a VR-5 and a VR-12.
>
>I did have a chance to examine the CTI amp. Perhaps they do not use the
>most modern circuitry and yes the tube dissipation is less than most other
>amps - but there was obviously a lot of pride in the manufacture of these
>amps. They are very well built and should last a long time. It is easy to
>criticize the design and used of these tubes, but they are the same tubes
>used by the KWS-1 -
Which ran the 4cx250Bs within their ratings, unlike the CTI.
>and that brings tears to the eyes of Collins lovers.
They had good audio.
>I wish my home built amps looked as good. One advantage of these amps over a
>wonderful new Alpha is that a ham with minimum test equipment could service
>them himself using inexpensive components.
>
* amen
>Would the amplifier have brought the same questions and challenges if it
>had a Collins label on it?
>
>The 4CX250 tube is not known for great imd performance. The Collins rig
>used feedback to improve the bottom line. The CTI picks up some
>performance using cathode drive, since that will add degeneration.
* However, g-g with a 2w grid is looneytunes for all but SSB.
>And,
>even though it does not use a tuned input, I believe the 3rd order
>distortion level would be close to or below -30db. Maybe that is good
>enough.
* No tuned input with g-g is not hardly engineering practice.
>
>So, maybe CTI overstates the qualities of their amp.
> ...
* Maybe Ted Kennedy is a Democrat.
- R. L. Measures, a.k.a. Rich..., 805.386.3734,AG6K,
www.vcnet.com/measures.
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