[AMPS] Six Weeks with the Henry Amps

[Jim Reid]

Aloha,

Quick summary:  they are FANTASTIC!!

Be pleased to e-mail .jpg images of these units to anyone interested.
I have the big 8K,  3CX3000A7 amp and the solid state SS500.
Each useful in its' own way,  and,  if it were legal and you had the
big hard-line,  connectors,  etc.,  etc. for the antenna system, the
two in series,  with about 41 watts from the transceiver to the SS500,
to produce about  410 watts of drive to the 8K would cause the tube to 
output 7.26 kW per the Eimac tube data sheet,  AB2 gnd'd grid.

I have been told that the principle market for Henry with these amps
seems to be the "third world" international short-wave broadcast
stations.  And they have great reputation for reliability in such service,
so I have heard.  In such service,  Henry rates the unit as a 5kW
amp.  The factory data that came with my unit shows it put
5kW into Henry's big dummy load with 200 to 275 watts of
drive from 160 on up through 10 meters, the 275 up on 10M.
I well never try that to find out;  I bought the unit for cool, 
conservative,  long, long life at our legal powers.  Plan to
try it amplifying AM signals up around 29MHz;  I love the
sound of those AM signals up there! Last AM rig I had
was a Viking II,  hi.

Also bought  from Henry an external new Bird to ensure that no 
more power than 1500 ever escapes from this guy when I am 
using it,  hi!!  Unit comes with a built in Bird coupler,  and read-
out indication on the remote amp controller unit,  but I wished for 
another out on the actual transmission line from the shack after 
all switches,  tuner, whatever.   However,  the Bird's movement/
sensor is damped such that it takes a few seconds to reach
up to the output level,  so also have the RF Applications 
P-3000 watt meter/vswr indicator in line after the amp.  This
unit has just been upgraded at the factory to quiet high
accuracy,  alleged close to  the Birds +/- 5% of full
scale accuracy.  And it is fast,  really neat,  but wanted
the  actual Bird accuracy for compliance assurance.

Folks at Henry modified the Controller Unit so that both Henry
amps can be used separately,  or in series.  Big amp has 24
preset,  user settable pairs of tune/load pots.  SS amp
has broad band filters which are controlled by the same band
switch as the 8K on the Controller,  neat!

I had to install a new station ground system;  and thanks to
Paul,  N6VLV of Henry who put me on to the correct
ground system to use -- lots of copper in the ground,  and
a completely separate ground set up for the 8K from the
rest of the station.

Both amps are a real pleasure to use,  very pleased about my
decision to buy these,  for sure!!  No longer intimidated by the
8K,  but in learning to set/tune it up,  did burn out two Alpha/
Delta coax switches,  so obviously had output a lot more soup
than intended,  thus the added fast acting P-3000 meter to
the chain!  Unfortunately,  the cable of my crank up tower broke
three weeks ago; the resulting fall damaged my beam,  but it
is now repaired.

Big feature for me is that both of these amps are remoted from
my control room "shack".  That removes blower noise and amp
heat completely,  a real benefit here in the tropics where it can
be pretty warm much of the year.  The Henry remote controller
unit is very complete,  and well metered.  And of course the 24 
pairs of precision tune/load pots bring you close to QSY quickly,
and just a tweak to touch up,  and your on!

Chased the 3B9R guys for several hours,  but could never break
the pile from here in KH6 land.  Their signal was fine here
last couple of days during our  early morning hours,  but
am afraid they were working only Europe,  at least that was
the bulk of the calls to which they were responding.  My beam
at only 20 or so feet high now just couldn't get a good signal
into the side of their beam aimed up to Eu,  I guess.  A few guys
down on the Big Island bagged them very early in the DXped.,
but I missed that opening with my antenna boom broken.

When I get the tower fixed,  expect to report more on the use
of the Henrys.

73,   Jim,  KH7M
On the Garden Island of Kauai
 



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