On Tue, 2006-07-18 at 12:50 -0400, CATFISHTWO@aol.com wrote:
> In reference to the ALC thing, I quite using an ALC line a bunch of years
> ago when an old Tube rig ( ft 101ee I think) was running into a Tube amp ( I
> think a Clipperton L) and the alc would cause the amp to motor boat, on TX.
> After a couple of different tries at a fix, one fellow on the air said he
> had
> the same problem a while back and just disconnect the ALC.
>
> I did that and it ran fine from there on out. I haven't hooked on up since.
> BUT what I do is on a manual tune amp, take it up to max smoke, then back
> the input down 5 watts or so. that way the amp is in resonance, but not
> trying
> to melt the plates.
>
> with the alpha 87 a I just run it legal power or less. ( It will do well
> over 2K in a dummy load) and usually drive it at 1K .
>
> I am also aware that I have no ALC on the linear to rig loop so I tend to
> watch it a bit more. 47 watts from the Orion will do better than 1k on the
> alpha
> and the grid current stays well down in the "green" range.
>
> works for me, for what ever that is worth.
>
> tom N6AJR
>
> appliance operator extraordinair !!!
>
>
> BTW I have had probably 3 clipperton ls, and amp supply 1000nt, a couple of
> ameritron 811's and 811 H's, a bunch of sweep tune amps , a couple of IC
> 2-KL's, an alpha 76A, 2 als 500's, an als 600 and a bunch of brick for HF
> and
> 2/440 and 6 m.
>
You are the exception if you watch closely and never overdrive the
amplifier.
The motorboating came from a problem of ALC time constant too fast.
Should have been fast attack, slow decay to prevent that.
Since you do have a mic gain in the Orion, you might have a CW drive
control and can use each on the appropriate mode to minimize exciter ALC
action and so develop a cleaner signal, but without as much compression
punch that lots of ALC action also provides. I predict that if the CW
equivalent of mic gain is turned down until there is very little ALC
action that the clicks will go away and that the rise time will be that
set, not shorter.
--
73, Jerry, K0CQ,
All content copyright Dr. Gerald N. Johnson, electrical engineer
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