[Elecraft] OT: manual & automatic tuners

[lhlousek]

Julian wrote:

>> As I recall, in the early 80s. (when automatic ATUs were first introduced)<<

I don't know when they were first introduced but I've seen automatic tuners that look to date from the 40's or 50's, maybe even earlier...they look to be some type of commercial, military, or maritime gear.

>>2. Manual tuners usually seem to be able to match a wider range of loads<<

Whether tuner is manual or automatic is irrelevant as far as its tuning range goes.  That depends on the network and components used.  Some automatic tuners use motors to drive variable capacitors and coils, some use relays to switch in binary weighted components (KAT1 and 2, LDG, SGC...), and some use a combination of both. 

>>The disadvantage is that it seems to take most people a couple of minutes to tune them up<<

Maybe for the initial tune up, but once you find it, is generally possible record the settings and simply return to them and operate.  Depending on the tuner and the SWR bandwidth of the antenna (and sometimes weather condx), it may be necessary to touch up the tuning but that shouldn't take more than a few seconds..

>>apparently it's necessary to do it at full power<<

I tune up at a couple of watts and then go immediately to 1.5KW with no problems.  The power should not affect the tuning.  If it does, something is probably wrong.  Tuning the output tank of a tube amp must be done at operating power but again, if the settings are recorded, you can usually just return to those settings and operate. 

Lou W7DZN


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