The dip occurs on the meter that measures plate current of the transmitter 
as the plate is close to resenance.   If it is neutralized properly it 
should be at the maximum output condition.   The loading can be adjusted to 
a higher plate current level but shouldn't be adjusted to any more than at 
maximum output.  This should maintain the proper current for the operation 
of the tubes.
This should be very close to the maximum output position.   A higher current 
will distroy the tubes without any increase in power.
Of course all this should be done with a tuned antenna or 50ohm load.

Wayne



Wayne



----- Original Message ----- 
From: "Michael Ryan" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, April 07, 2015 5:54 PM
Subject: puzzling


> Hi Howard and all:=20
>
> According to Tom W8ji, the guy who designed and was in charge of the =
> ameritron AL-811 and AL-80 series prior to MFJ,=20
> under loading an amplifier and over loading can damage 1 part of the =
> tube or the other.=20
> This makes no since to me as you can't graft parts of tubes together to =
> make a good 1. LOL=20
> I do get it a little that under loading can put unnecessary strain on =
> tube components.=20
> Theres a balance there that has to be met. Can't explain it but it makes =
> a little sense.=20
> What puzzles me though is the camps. 1 group says you can under load an =
> everything be fine while another says you can't. LOL=20
> On dipping my plate on my 102 using the TW-1, maybe its my meter, maybe =
> its me,=20
> when I reach the peak pitch for max power, I can still rotate my plate =
> control a little bit more before the pitch begins to decrease.=20
> Like going up 1 side of a bridge, crossing the top and going down the =
> other side. While I'm crossing the top, there's no increase in power but =
> the current is still going up.=20
> I didn't know this of course until I got my XYL to look over my shoulder =
> this past weekend when tuning up my 102.=20
> My amp on the other hand has a shorter bridge top, that's what I'll =
> refer to it as. Somewhere in the middle of both tops, there's a slight =
> ripple in the tone.=20
> Perhaps this is the dip? At any rate, I'm now using my 102 with the load =
> below 3 instead of 6 and my plate is between the 275/300 mark,=20
> spec say 300MA max and I'm getting 150W key down.=20
> With my load at 6 and a plate current of 350, I was getting an extra =
> 25/30W.=20
> Not worth it as I would reduce an run an amp.=20
> That to was a problem as I didn't have things properly loaded up for the =
> power I was driving the amp with.=20
> Not to mention the 102's SSB drive is controlled by the mic-gain.=20
> So I'd tune up in CW, switch to SSB and of course everything went out =
> the window.=20
>
> 73:=20
> Mike DE VO1AX=20
>