I got one at swapmeet with a problem. It works fine on the Short side
but on the Open side on check the eye stays open instead of being
closed. The wiring and tube seem OK. The schematic I have shows a 5mmf
cap across the osc coil but I don't see one and wonder if it was missing
from the factory because the parts list doesn't show a 5mmf cap. I'm
guessing the coil came with both caps as an assembly or my unit is a
later one and they may have figured out a way to wind the coil where
they don't need it. Anyone know? Scoping the grid I can see a flash of
high freq. osc momentarily but that's switching in the Short side.
tnx

--

73
Hank WD5JFR

"Henry Kolesnik" wrote in message
et...
I got one at swapmeet with a problem. It works fine on the Short side but on
the Open side on check the eye stays open instead of being closed. The wiring
and tube seem OK. The schematic I have shows a 5mmf cap across the osc coil
but I don't see one and wonder if it was missing from the factory because the
parts list doesn't show a 5mmf cap. I'm guessing the coil came with both caps
as an assembly or my unit is a later one and they may have figured out a way to
wind the coil where they don't need it. Anyone know? Scoping the grid I can
see a flash of high freq. osc momentarily but that's switching in the Short
side.
tnx

--

73
Hank WD5JFR

The manual I have for the CT-1 shows a 10 pf capacitor across the oscillator
coil, however, it's not in the parts list either. The oscillator coil must have
come from the factory assembled with a tuning capacitor that made the circuit
oscillate at the correct frequency.
Do you have a complete manual that gives the circuit theory of operation? That
section describes both open and short checks as well as normal operation. If
not, I can send you a PDF of the manual.

Cheers!!!
--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate characters in the
address)

"In theory, there isn't any difference between theory and practice. In
practice, there is." - Yogi Berra

Dave
Thanks for the offer but I have a manual copy that seems to be god
enough..
I'm hoping some one who sees the post and has a CT-1 has the time to
take a look inside to see if there;s really a 5 mmf cap across the coil.
Right now I'm trying to recall what junkbox of my many might have one..
Hank
"DaveM" wrote in message
. ..
"Henry Kolesnik" wrote in message
et...
I got one at swapmeet with a problem. It works fine on the Short side
but on the Open side on check the eye stays open instead of being
closed. The wiring and tube seem OK. The schematic I have shows a
5mmf cap across the osc coil but I don't see one and wonder if it was
missing from the factory because the parts list doesn't show a 5mmf
cap. I'm guessing the coil came with both caps as an assembly or my
unit is a later one and they may have figured out a way to wind the
coil where they don't need it. Anyone know? Scoping the grid I can
see a flash of high freq. osc momentarily but that's switching in the
Short side.
tnx

--

73
Hank WD5JFR

The manual I have for the CT-1 shows a 10 pf capacitor across the
oscillator coil, however, it's not in the parts list either. The
oscillator coil must have come from the factory assembled with a
tuning capacitor that made the circuit oscillate at the correct
frequency.
Do you have a complete manual that gives the circuit theory of
operation? That section describes both open and short checks as well
as normal operation. If not, I can send you a PDF of the manual.

Cheers!!!
--
Dave M
MasonDG44 at comcast dot net (Just substitute the appropriate
characters in the address)

"In theory, there isn't any difference between theory and practice.
In practice, there is." - Yogi Berra

On Oct 8, 5:03 pm, "Henry Kolesnik"
wrote:
Dave
Thanks for the offer but I have a manual copy that seems to be god
enough..
I'm hoping some one who sees the post and has a CT-1 has the time to
take a look inside to see if there;s really a 5 mmf cap across the coil.
Right now I'm trying to recall what junkbox of my many might have one..
Hank"DaveM" wrote in message

. ..

Henry, I just opened mine and it has a 10pF NPO ceramic across the end
of the coil opposite the green dot [the left end looking from the
rear]. The frequency of the oscillation in not as critical as it
operating over the range of loads, so I should try 10pF and see how it
works with a variety of capacitor values under test. If it craps out
at either end of the load range, try 5, 15 or 20pF and see how it
goes.

Neil S.

Hi Neil
Mine has the 10mmf on the end opposite the green dot..
But my schematic shows a 5mmf across the big coil which mine doesn't
have..
Does yours have a 5 mmf on the coil as shown on the schematic and in
Fig. 3 page 11?
tnx
Hank
"nesesu" wrote in message
oups.com...
On Oct 8, 5:03 pm, "Henry Kolesnik"
wrote:
Dave
Thanks for the offer but I have a manual copy that seems to be god
enough..
I'm hoping some one who sees the post and has a CT-1 has the time to
take a look inside to see if there;s really a 5 mmf cap across the
coil.
Right now I'm trying to recall what junkbox of my many might have
one..
Hank"DaveM" wrote in message

. ..

Henry, I just opened mine and it has a 10pF NPO ceramic across the end
of the coil opposite the green dot [the left end looking from the
rear]. The frequency of the oscillation in not as critical as it
operating over the range of loads, so I should try 10pF and see how it
works with a variety of capacitor values under test. If it craps out
at either end of the load range, try 5, 15 or 20pF and see how it
goes.

Neil S.

The CT-1 uses an oscillator tuned to approximately 19 MHz for the open test.
It does not matter if it is 21 MHz or 17 MHz, and there will be no
difference between a 5 pf or a 10 pf or no pf across the coil.

If no one got offended, I would say that you are barking up the wrong tree.
But, I do not want to hurt anyone's feelings, so I will not say that. My
dog would not get her feelings hurt if I talked like that to her, but people
do.

The problem is elsewhere.

One of the problems, when you pick up something that does not work, is
assuming that it ever worked. Sometimes kits were assembled, and did not
work, then put on the shelf where they languished for decades.

Check the wiring and check to see if the oscillator is oscillating.
Sometimes switch contacts are wired incorectly. Sometimes switches are
improperly cleaned then fail Sometimes resistors fail.

In the past, we check the paper and electrolytic caps. Now, we may need to
check the mica caps.

Colin K7FM

good statement - don't assume it ever worked - at one time I made my spare
change fixing kits that the purchasers couldn't assemble correctly.


"COLIN LAMB" wrote in message
...
The CT-1 uses an oscillator tuned to approximately 19 MHz for the open
test. It does not matter if it is 21 MHz or 17 MHz, and there will be no
difference between a 5 pf or a 10 pf or no pf across the coil.

If no one got offended, I would say that you are barking up the wrong
tree. But, I do not want to hurt anyone's feelings, so I will not say
that. My dog would not get her feelings hurt if I talked like that to
her, but people do.

The problem is elsewhere.

One of the problems, when you pick up something that does not work, is
assuming that it ever worked. Sometimes kits were assembled, and did not
work, then put on the shelf where they languished for decades.

Check the wiring and check to see if the oscillator is oscillating.
Sometimes switch contacts are wired incorectly. Sometimes switches are
improperly cleaned then fail Sometimes resistors fail.

In the past, we check the paper and electrolytic caps. Now, we may need
to check the mica caps.

Colin K7FM







--
Posted via a free Usenet account from http://www.teranews.com

On Oct 8, 7:34 pm, "Henry Kolesnik"
wrote:
Hi Neil
Mine has the 10mmf on the end opposite the green dot..
But my schematic shows a 5mmf across the big coil which mine doesn't
have..
Does yours have a 5 mmf on the coil as shown on the schematic and in
Fig. 3 page 11?
tnx
Hank"nesesu" wrote in message

oups.com...



On Oct 8, 5:03 pm, "Henry Kolesnik"
wrote:
Dave
Thanks for the offer but I have a manual copy that seems to be god
enough..
I'm hoping some one who sees the post and has a CT-1 has the time to
take a look inside to see if there;s really a 5 mmf cap across the
coil.
Right now I'm trying to recall what junkbox of my many might have
one..
Hank"DaveM" wrote in message

m...

Henry, I just opened mine and it has a 10pF NPO ceramic across the end
of the coil opposite the green dot [the left end looking from the
rear]. The frequency of the oscillation in not as critical as it
operating over the range of loads, so I should try 10pF and see how it
works with a variety of capacitor values under test. If it craps out
at either end of the load range, try 5, 15 or 20pF and see how it
goes.

Neil S.- Hide quoted text -

- Show quoted text -

I checked mine and the schematic does not show any cap across the
'large' coil, nor is there one. You might check the cathode for
oscillation activity since virtually any capacitance across the
secondary will kill the oscillation [even a 'scope probe]. There is
not a whole lot in there to go wrong, so you might check the eye tube
triode for emission; if it is weak that could be a problem, or if it
has been inactive for a long time. Mine has not been used since I
refurbished it 10 or so years ago, and it worked immediately I turned
it on and the tube warmed up.

Neil S.