[TenTec] LEGAL LIMIT PLUS AMP ALPHA 77D

[Jim Brown K9YC]

On Tue, 8 Apr 2008 09:47:38 -0500, Bob McGraw - K4TAX wrote:

>This basically defines why 
>the bands are full of QRM and crap during contests.  Everyone wants to call 
>all the time and listen a lesser amount of time.  I believe it is skill and 
>not power that wins contests.

It takes skill, power, antennas, and LOCATION. The rules of most contests 
combine with geography to favor DX stations in certain parts of the world and 
stations on the east coast of the US. Since moving to CA, I've gotten to know 
several top notch contesters. Without exception, they have worked to build top 
notch stations -- antennas, both transmitting and receiving, great radios, and 
power. Google W9DX, N6RO, K5RC, K3LR, K6XX, NQ4I, and W8JI to see examples. 

I've sat with headphones next to WX5S and heard him pull SSB exchanges out of 
what I heard as nothing but noise. I've watched N6RO and N6BV run SO2R on both 
CW and SSB. None of these guys run less than (or more than) legal power. On 
the other hand, N6WG, the current president of NCCC, a premier contest club 
here in the Bay Area, ALWAYS runs QRP. 

Top-scoring contesters CQ all the time. Most ARE listening, and the good ones 
have good RX antennas. Most are also listening in one ear to a second radio or 
second VFO, and often make a QSO on that other frequency in between Q's on 
their CQ frequency. Yes, a few lids will CQ automatically without listening.  

>I've had three Titans in the shop for various reasons and repairs.  Most 
>faults have been found to exist due to mis-use or operation by the owner 
>which turned out to be failure to properly connect and operate for QSK.  One 
>due to lightning damage.  I don't find them to be "light weight" in terms of 
>performance or duty cycle for amateur radio service.  A 50% duty cycle, 10 
>min on and 10 min off, for 100% duty cycle modes such as RTTY.

Lightweight is "compared to what?"  I run my Titan 425s so that the grid 
current never exceeds about 30 mA. Depending on condition of the tubes, that 
gives me about 1,200-1,400 watts on most bands. When I'm contesting, I run 
more or less continuously. I always run full QSK. I've never had a failure I 
could blame on pushing the amp. I HAVE had component failures -- the vacuum 
relay -- and almost anything that creates an arc will toast a couple of traces 
in the power supply. That arc can be from an antenna or antenna tuner failure, 
a tube, a capacitor, or from a power line transient. I recently started 
running RTTY in a few contests. Not knowing how the Titan would handle it, I 
started at 500W out, then went to 700 watts, then to 900 watts, CQing for 3-4 
seconds with a 3-4 second listening break. Holding my hand a few inches over 
the chimney told me that even at 900 watts, the amp was running cooler than CW 
or SSB at 1,400 watts. 

73,

Jim K9YC