TITAN II Mods and Hints
In case others are frustrated with their
Titan II's, I offer them this
FYI:
My new Xmas present to myself had a fan which
sounded like a helicopter and even shook the table. I cured that entirely
objectionable problem by constructing a
pressurized wooden platform for the amp to sit upon. The one inch thick
material is 5 1/2 inches high, thus also elevating the amp to a more desirable
height for viewing its meters. The top and bottom edges are lined with thick
felt strips for an air tight fit. A 10 foot long clothes dryer hose (4"
dia.) runs from this base to a cubby hole closet which our house builder
conveniently provided under a short stairwell. In there is a remote squirrel
cage blower, Fasco cat. no. F2-2440, ordered online from www.herbach.com. It's
made in USA and its dynamic pressure and volume exceed that of original Titan
II's fan. Its round outlet flange snuggly fits directly into the clothes dryer
hose. I glued it in there with Shoo Goo. The blower is well balanced, smooth
and quiet with no radio noise. The original fan was removed and set aside. Air
enters through the original fan's bottom hole. The amp's rear feet were
removed. This remote blower concept is not mine--Collins used it in their model
AM-1 if my memory serves me right. The Titan II is now virtually silent in
operation. The slight hiss of air exhausting from the jug is subdued by placing
a chimney-like muffler over the exhaust port. It is big enough to have no
restriction of air flow and is lined inside with sound absorbing material. Both
the platform base and the chimney muffler are painted Ten-Tec gray.
Now for the second objectionable problem. Two
ceramic disc caps are switched in parallel with the variable loading cap during
80M operation. These caps are
unbelievably small and cheap. (No padder is used for the plate tuning cap on
80M, thank goodness). They drift like crazy during a transmission, being
manifested as sagging output and lowering screen current, often down to the
point of negative screen current. All this concerns CW operation at full 1500
watts out, into a perfect 50 ohm load (Nye Viking tuner). I have not tested it
on SSB.
The cure for this second dilemma was to
install a single 320 pF xmitting mica, rated 2.5 A @ 5 KV in their place. I
"remote located" the new cap, placing it near the fil (heater) xmfr.
A short piece of good quality RG 58 connects the cap to the bandswitch. The
shield is grounded at both ends. The job was performed in such a manner that
the amp can be easily and speedily restored to original for you know what
reason. The original two caps' total value were twice that of the new the 320
pF value, causing the loading control to run more than half way open. This new,
lower value allows the variable loading cap's plates to operate in a more fully
meshed position (number 7 when operating on 3522 kHz). Now both the plate
tuning and loading dials read approximately the same; plate remaining at number 8 on 3522 kHz. This new loading
setting allows for more circulating current in the variable loading cap and
less in the padder.
The improved system has been tested with
excellent results. Now the readings remain perfectly solid at all times. I
don't presently use 160M. But I'm sure a similarly awful situation exists
there, where both ceramic plate tuning and plate loading padders are switched
in!
73,
Roy K6XK Iowa Outback