[Amps] Alpha vs Henry

Jim Thomson jim.thom at telus.net
Wed Apr 6 02:55:35 PDT 2011


Date: Tue, 5 Apr 2011 09:55:35 -0700
From: "Mike" <noddy1211 at sbcglobal.net>
Subject: Re: [Amps] Alpha vs Henry

Yup, but when I checked at Visalia it was sending a string of Dit's.  Not
the same key down modulated carrier.

-Mike

-----Original Message-----
From: amps-bounces at contesting.com [mailto:amps-bounces at contesting.com] On
Behalf Of Robert Harmon
Sent: Tuesday, April 05, 2011 8:58 AM
To: Damon Stewart
Cc: amps at contesting.com
Subject: Re: [Amps] Alpha vs Henry

Remember the ad for the Alpha 76 amps with the brick on the key ?


Bob

### Art Bell, W6OBB had his cat fall asleep on the footswitch one day,
and his beloved Alpha 87-A was tuned up on 10m FM.  The 87-A was
sitting there pumping out a  1.5 kw FM CXR  for a long time.  When
he got back from shopping, the entire tank circuit had melted, molten glop
every where, overheated xfmr, etc. The ant still had a flat swr, and he had the optional fan on it. 
[papst brand, supplied by alpha, goes on the rear wall, used to cool tank circuit.]
He phoned alpha and talked to the tech..and said.. " what abt the NO time limit, etc"
Alpha tech told him... " don't believe the advertising hype".

##  I have also heard  from several other's,  that Alpha  pulse tunes their amps during these
various demo's  around the country. Since their built in wattmeter's  are all peak reading led types,
and have no provision to read average power, Joe end user thinks the amp is putting out a dead cxr,
and that the entire cab is nice and cool, including the xfmr.  No wonder, with a low duty cycle, + 
electronic bias switching to cut off the idle current between dots, it wouldn't even be breaking a sweat. 
On my MK-V, it's easy to adjust the dot and dash length's individually, in the menu....and shorten the duty
cycle of a string of dots, from the usual 50%....down to < 10% .  The tank eff on any alpha amp, on 10M
is barely 50-55%.  Any amp that's dissipating  1200-1500 watts, is gonna get hot, and that's a LOT of heat to get
rid of.  Think of your wife's  kw hairdryer in the 1200-1500 w mode. 

later... Jim  VE7RF


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