Mike,

Yeah, I do it twice.    After presetting plate and load controls, I tune 
at 15 watts, then increase to 70-75 watts, and tweak it  as needed. 
Then advance load and reduce drive.

I'll advance the load knob just a small amount (clockwise).   You might 
see power  drop just a bit.  then reduce drive to get what you want 
final output to be.

There is a lot of stuff on the web, like W8JI's site,  and even in the 
manual, explaining that  running with the amp too lightly loaded is  bad 
for the amp.
73, Steve KW3A

On 12/8/2015 3:46 PM, Michael Ryan wrote:
> Ok Steve, do you do 2 tune ups? IE: when I tune up my 811H, I star by getting the max with 20W of drive, then go up to 65.
> Get the peak power there and then reduce to about 40 or 45W of drive for 500 or so CW. When you advance the load during your tune up, how do you know how much to advance? the load? Is  there an increase of power  and thats how you know you've reached top end and then reduce your drive to the output you want?
> I'm considering an 80B if nothing else for the better tube. I find my self nit picking at my drive levels because of the fragile 811A tube. Ie: I may go to 75W sometimes when setting up for my 2ND step and  have to reduce my drive to 65W before starting. I wouldn't mind an amp where I could go from  20, hit 70 or 75 for my 2ND step and not worry about it.
>
> 73:
> Mike DE VO1AX
>
>
>
> On Dec 8, 2015, 4:50 PM, at 4:50 PM, Steve Forst <[log in to unmask]> wrote:
>> Mike,
>>
>> I do use the TW-1 for tune up, but  find it to read low for power
>> readings.     I have a Wavenode WN-2  computer controlled swr/watt
>> meter.     It compares favorably with the analog meters in the shack
>> (amps, and tuners), while the TW-1 always reads low.
>>
>> The amp is rated at 1KW SSB, 800 CW, and 500 RTTY, but  I never push it
>>
>> to the limit.     I had to replace the original tube about  a year and
>> ahalf ago, with one from RF Parts.    Seems like a bit more   output
>> than the original.   Can see more than a KW on most bands, but   I
>> don't
>> like the smell of smoke.
>>
>>
>> I usually tune at 75 watts drive and  then advance the load, then
>> reduce
>> drive   to get output I want.    I was running 65 watts drive over the
>> weekend to get just under 700 out on 160 CW.
>>
>> Any difference in drive between CW and SSB is going to be influenced by
>>
>>   stuff like microphone,  mic gain, compression, etc.   The manual
>> suggests setting  up for a max key down  output of 800 watts, and voice
>>
>> peaks will be hitting the 1 K level.  Assuming you want to run
>> everything to the max.
>>
>> I'm not sure I would drive it with 100 watts under any circumstances.
>>   For my setup, even 85 seems a bit much.  If you are going to keep
>> drive set at 100 watts, use of ALC might be a good idea.
>>
>> Mine has the grid protection board installed.    I've only had it trip
>> a
>> couple of times.  Usually at the start of a tune, if the controls
>> weren't set   to the proper initial settings.
>>
>> 73, Steve KW3A
>>
>>
>>      .
>>
>>
>>
>>
>> On 12/8/2015 2:10 PM, Michael Ryan wrote:
>>> Hi Steve (KW3A)
>>>
>>> You run an AL-80B right? Do you use a TW-1 for readings?
>>> What's the headroom like on that amp? How much drive does it take to
>> get rated outputs in both CW and SSB?
>>> According to the Manual, the typical drive for rated output is 85W
>> but the max drive permissible is 100 plus watts.
>>> Do you get these numbers?
>>>
>>> TNX and 73:
>>> Mike DE VO1AX
>>>
>>> Sent from BlueMail
>>>
>