[Amps] Amplifier Tuning Device

[Jim Thomson]

Date: Mon, 10 Sep 2012 11:14:20 -0700
From: "Bill, W6WRT" <dezrat1242 at yahoo.com>
To: AMPS <amps at contesting.com>
Subject: Re: [Amps] Amplifier Tuning Device

ORIGINAL MESSAGE: 
On Mon, 10 Sep 2012 11:00:42 -0700, N6ML wrote:

>> As I recall, there is some kind of device that is used to tune an amp. It
>> acts like a telegraph bug sending dots.

REPLY: 
One thing to be wary of with any pulse type tuning device is they do not load
down the power supply fully. When you go to a full carrier and the PS voltage
drops further, you run the risk of "flat-topping" the RF cycle and causing
distortion. 

Just something to keep in mind. 

73, Bill W6WRT

### Not quite. Sure, the low duty cycle pulse will not load the B+ supply down
like a dead cxr will,but that will not cause the amp to flat top.... while running 
100% duty cycle modes like RTTY-FM etc.  But if the amp is capable of 100%
duty cycle operation, its sorta  a moot point anyway.   For RTTY-FM  operation,
I would suggest just pulse tuning it with a 50%  duty cycle 1st,..then switch to
a 100%  dead cxr  for the final tweak.   That way it takes the initial load off the tubes
if the amp is off resosnance, etc, when 1st tuning it up. 

## If you intend to tune up the amp for CW use, then pulse tune with a 50% duty cycle. 
If you intend to tune up the amp for  SSB use, then pules tune using a 30% duty cycle.
If you intend to run loads of processing on ssb, then  use a 40-50%  duty cycle.

Jim  VE7RF