Hi Eddy:
Couple of things...sorry I'm late with this.
1. Tri-Flow is indeed a teflon-based spray lubricant. has a distinct
odor of amyl acetate as well..."banana oil" It is a very nice lubricant
for "dry" type applications. It might be appropriate on the yoke slider
for instance on the PTO. Not for gears or items requiring oil. Good
for sliding-type applications. Not messy.
2. Regarding your replacement of the SM cap with two parallel caps
(twice the value) Sounds like you have applied the resistors in
parallel formula to caps...Actually it is exactly the opposite for
Caps...two caps in parallel ADD the two values. (total plate area is
increased). ie, if you put in two parallel caps each one of twice the
value of the original, your total is now 4x the original. To get the
original value as a total, you need two parallel caps of 1/2 the
original value.
Surprised no one else picked this up.
Maybe you just wrote it wrong but worth a check...don't want to add a
problem to the PTO that adds to the first problem!! :)
Curt
KU8L
On 7/29/2011 7:58 AM, Eddy Swynar wrote:
Hi Steve,
I've been reading the posts re. your "progress"(!) in this maTTER with
great interest, because your experience basically mirrors that of my
own here in the matter of the PTO travails that I continue to have
with my T-4X transmitter...
To summarize, here's what I did with mine in hopes of finding a final
"cure":
---I allowed the rig to warm-up for a minimum one hour before using it
on the air. Result: the jumpiness was less prevalent after this time
period---but it was still there.
---I installed the "insurance" grounding strap on the yoke recommended
by Drake & others here on the Reflector. Result: no change.
---I pulled the plug on the external fan that I'd mounted over the PA
enclosure, with hopes that thermal instability of some kind might be
the cause of my PTO "jumpiness". My theory (hope...?!) was that the
PTO wasn't getting proper;y "heat soaked" in my cool basement
environment, and that by allowing everything to properly warm-up, the
problem would be gone. I even wrapped the T-4X with paper for better
heat retention. Result: no change.
---I "gasketed" the entire bottom periphery of the PTO enclosure with
aluminum foil & tape to better ensure the integrity of the "sealing"
of same. Result: no change.
---After dis-assembly of the PTO board from its moorings, I detected
COLD SOLDER JOINTS on the main (large) silver mica capacitor. I
replaced this cap with TWO brand new S.M.'s in parallel (each being
twice the value of the original, of course). Result: no change,
although the rate of occurance was less.
My latest finding was this: in one extensive operation on the air
recently, the frequency stability became REALLY bad---and STAYED that
way, continually (a GOOD thing, really, as few things are as vexing in
trouble-shooting as "...intermittants"). Not having the cover off of
the rig, I "probed & poked' the yoke of the PTP drive with a long
wooden chopstick & found that I could affect the instability by
judicious application of pressure of the stick!
This does NOT seem right to me, and leads me to suspect---in my case,
anyway---that another complete tear-down of the PTO "works" is in my
future, to be followed by a THOROUGH cleansing of everything in sight
that moves with a wash of isopropyl rubbing alcohol & Q-tips...no
guarantees that this'll work, either, of course---but hope springs
eternal.
Your sad experience with replacing the transistors affirms in my mind
that I should NOT take that same route with my PTO here, and that the
issue is---as is the case with so many things in radio &
life!---probably the result of something extremely trivial (on first
glance) that would most likely be very easy to fix, and consequently,
is readily overlooked...
...But as I say, hope springs eternal! Hi Hi
~73~ de Eddy VE3CUI - VE3XZ
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