fixture is sold..thanks
Jerry Massengale
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Re: 549 with compresssed trace on right third of screen
Hi Keith
Areovox capicator has 0,9?F insteat 0,5?F, that is a typical paper-capicator-problem.
i think, 1N4148 is better, but i am not sure.
dirty contact, i use tuner 600 and q-tips.
Best regards.
matt
Thanks for guestbook in wellenkino.de :-)
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--- In TekScopes@..., "keithostertag" <keitho@...> wrote:
Hi Matt-
Yes, thank you so much!
As you said, I replaced the Aerovox cap (C335) and that particular problem is resolved!
The bad cap did not show any leakage. On an ESR meter it measured much _lower_ than other similar type caps.
I accidentally broke diode D334 (clumsy) while replacing C335. I replaced it with a generic 1n4004, hope that's OK, seems to work.
Since you have experience with these 549's, are there any other specific common problems with them that you'd like to mention? Lots of switches and pots to clean...
Thanks,
Keith Ostertag
-
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Re: 549 with compresssed trace on right third of screen
Hi Matt-
Yes, thank you so much!
As you said, I replaced the Aerovox cap (C335) and that particular problem is resolved!
The bad cap did not show any leakage. On an ESR meter it measured much _lower_ than other similar type caps.
I accidentally broke diode D334 (clumsy) while replacing C335. I replaced it with a generic 1n4004, hope that's OK, seems to work.
Since you have experience with these 549's, are there any other specific common problems with them that you'd like to mention? Lots of switches and pots to clean...
Thanks,
Keith Ostertag
-
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Bought a 310A for little money, in perfect condition, optically and
electrically (what a sharp trace!), lucky me.
2 Questions:
It has serial number 013491, rectifier is with silicon diodes.
Anybody has an idea on which year this little oven was built?
Currently the transformer is wired for the "middle" tap. When I measure
my line voltage, it is 230V, with very little variation. Would it make
sense to wire the scope for 240V, to reduce voltage and heat stress?
Roland
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Looking for TDS420(A) Power Supply
Hi!
My TDS420A has a defective mains power supply.
Would any of you have one available from a parts mule?
AFAIK, PSU's in TDS420 and TDS420A are identical. True and any more models?
N.B. I'm living in Amsterdam, so shipment to The Netherlands.
Thanks,
Raymond
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Re: 549 with compresssed trace on right third of screen
Sorry, my fault.
0,5?F , (C335), that is right.
Heerenveen 549 has EROmet capicator, germany capicator.
But, Portland 549 has bad black areovox, replaced him and 549 run fine.
Best regards
Matt
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--- In TekScopes@..., "mattko87" <matt8@...> wrote:
Hi
pleas replaced 0,33?F Areovox capicator in Horz. amplifier.
This capicator ist bad.
I has repaired many 549, one from Nethersland (Heerenveen) has not this Problem, but Portland-549 has this problem awalys.
Best regards
matt
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Re: Delta Standard for 130 L-C Meter has MINUS 3pF setting [1 Attachment]
=================
How did Tek get the Delta Standard for the 130 L-C Meter to have a 0pF and a
MINUS 3pF value?
Exactly what is a negative capacitance and what is it good for?
See attached photo.
=================
The clue is in the word Delta, Dennis.
Craig
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Re: 549 with compresssed trace on right third of screen
Hi
pleas replaced 0,33?F Areovox capicator in Horz. amplifier.
This capicator ist bad.
I has repaired many 549, one from Nethersland (Heerenveen) has not this Problem, but Portland-549 has this problem awalys.
Best regards
matt
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Re: Delta Standard for 130 L-C Meter has MINUS 3pF setting [1 Attachment]
They do not have 0 and -3pF. The fixture ( I would love to have the original, but made one myself as a substitude) has a starting capacity. I do not remember the values but for instance 3 pF on the meter is something like 13 pF, so 0pF is 10 and -3 is 7 pF . The fixture gives relative values about a " floating" zero. Because the trimknob on the front, the real zero or real value is not important, as long as the deviation is 3 its OK because you use the zero knob to get the right startpoint while measuring.
I used a what higher startvalue so I could zero out enough cable. But that gave problems using a fixture I made that screws direct on the meter with two croks. But adding a small variable capacitor on the fixture solved that problem.?
A very nice and accurate meter.
Fred PA4TIM
Op 3 mrt. 2013 om 04:51 heeft "Dennis Tillman" < dennis@...> het volgende geschreven:
?
How did Tek get the Delta Standard for the 130 L-C Meter to have a 0pF and a MINUS 3pF value? Exactly what is a negative capacitance and what is it good for? See attached photo. ? Dennis
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Re: Delta Standard for 130 L-C Meter has MINUS 3pF setting [1 Attachment]
On Sat, Mar 2, 2013 at 8:51 PM, Dennis Tillman <dennis@...> wrote: How did Tek get the Delta Standard for the 130 L-C Meter to have a 0pF and
a MINUS 3pF value? "Only the stray capacitance of the connector and switch assembly is in the circuit in the -3uufd position. The actual capacitance of these strays is approximately 10 to 20uufd. No effort is made to standardize this value. As the switch is rotated, capacitors are switched into the circuit to provide a change (or "Delta") of capacitance as indicated. In the 0uufd position, an additional 3uufd has been added in addition to the strays."
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Re: Delta Standard for 130 L-C Meter has MINUS 3pF setting
The service manual is available online if you want to see how it works. "Only the stray capacitance of the connector and switch assembly is in the circuit in the -3pF position. The actual capacitance of these strays is approximately 10 to 20 pF. No effort is made to standardize this value. As the switch is rotated, capacitors are switched into the circuit to provide a change (or "Delta") of capacitance as indicated. In the 0pF position, an additional 3 pF has been added in addition to the strays." On Sun, 03 Mar 2013 04:16:59 -0000, "Ed Breya" <edbreya@...> wrote: Since it appears to be a passive device, it is probably and inductance that's equivalent to -3 pF at the test frequency. The zero value is probably an L-C resonant (near the test frequency) circuit that can be adjusted to a null.
Ed
--- In TekScopes@..., "Dennis Tillman" <dennis@...> wrote:
How did Tek get the Delta Standard for the 130 L-C Meter to have a 0pF and a
MINUS 3pF value?
Exactly what is a negative capacitance and what is it good for?
See attached photo.
Dennis
|
Re: Delta Standard for 130 L-C Meter has MINUS 3pF setting
Pages 6-6 and 6-7 of the 130 manual describe the cal procedure using the S-30 + and - 3pf setting.
RP
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Re: Delta Standard for 130 L-C Meter has MINUS 3pF setting
Since it appears to be a passive device, it is probably and inductance that's equivalent to -3 pF at the test frequency. The zero value is probably an L-C resonant (near the test frequency) circuit that can be adjusted to a null.
Ed
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Show quoted text
--- In TekScopes@..., "Dennis Tillman" <dennis@...> wrote:
How did Tek get the Delta Standard for the 130 L-C Meter to have a 0pF and a
MINUS 3pF value?
Exactly what is a negative capacitance and what is it good for?
See attached photo.
Dennis
|
Delta Standard for 130 L-C Meter has MINUS 3pF setting
How did Tek get the Delta Standard for the 130 L-C Meter to have a 0pF and a MINUS 3pF value? Exactly what is a negative capacitance and what is it good for? See attached photo. ? Dennis
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Re: Tektronix 2465 Ch2 dead
The outputs from the U140 and U150 shift registers control more than
the attenuator relays. The outputs can change after the relays are
activated by the strobe signal from U130G without affecting the
relays. (I am going by the 2465B schematic which I have a nice copy
of.)
If you have an analog or digital storage oscilloscope, you could
trigger it on the relay strobe signal while watching the different
outputs of U140 and U150 to see if they match.
I would check the coil resistance of each relay and make sure they are
all good but I suspect you will find that the problem is inside of the
attenuator assembly.
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On Sat, 02 Mar 2013 20:42:28 -0000, "J_O" <pecska@...> wrote: Hi Guys !
I need a little help to fix my scope.
Ch1 is working fine, diagnostics is OK.
No signal comes out Ch2 attenuators - testpoint 11
If I set the input attenuators to 1V/Div and compare U140 and U150 pinouts I see differences. Should they be the same for swiching the same relays?
On front panel all swiches indicate the same, I hear clicks at the same time if rotating V/Div knob.
Your help is much apreciated
Joe
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Hi Guys !
I need a little help to fix my scope.
Ch1 is working fine, diagnostics is OK.
No signal comes out Ch2 attenuators - testpoint 11
If I set the input attenuators to 1V/Div and compare U140 and U150 pinouts I see differences. Should they be the same for swiching the same relays?
On front panel all swiches indicate the same, I hear clicks at the same time if rotating V/Div knob.
Your help is much apreciated
Joe
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Re: 466 Trigger on <1Hz Square Wave?
Cliff,
? It sounds like your trigger point is close to the baseline and triggering on noise.?
?
? Here is a round about way to set the trigger point, assuming that your 5V p-p signal will fill most of the screen:
Set Storage to Normal (Non-Storage)
Set Horiz sweep to "A"
Set Sweep to "Auto" mode
Set Time/Div to "1mS"
Set Trigger Coupling to "DC"
Setup Ch1 to show trace at mid screen with input "Gnd"
Rotate Pos control and watch A Swp Trig'd light flash at the sweep trigger point
Adjust the A Sweep Trigger "Level" control so the trigger point occurs about half way up your waveform
?
Now reset Ch1 to show your signal swinging below and above the mid line
Set Sweep to "Norm Trig"
Walk the Time/Div to longer sweeps so you can observe the leading edge of your signal
You may have to change Trigger Polarity (and readjust the trigger level)?to observe the portion of the signal of interest
Set the Time/Div as required
?
Denis K
From: Cliff White To: TekScopes@... Sent: Saturday, March 2, 2013 11:04 AM Subject: Re: [TekScopes] 466 Trigger on <1Hz Square Wave?
?
I have it set to normal mode, I've tried both AC, DC, and HF reject couplings, and the channel itself is coupled DC. But it still seems to only want to trigger on the little bit of ripple on the wave, and not actually the signal itself.
On 03/02/2013 12:12 AM, David wrote: You can absolutely trigger on low frequency signals including slow
ramps. Be sure to set TRIG MODE (below the time/div control on the
right side) to NORM instead of AUTO to prevent the sweep from free
running when the triggers occur slower than about 20 Hz.
You may need to use DC input coupling and DC trigger coupling.
On Fri, 01 Mar 2013 22:12:46 -0600, Cliff White
mailto:cn.white@... wrote:
I have a case where I need to use my 466 to view a /very/ slow (less
than one Hertz) 5 volt p-p square wave. Is it possible and/or easy to
make it trigger on such a signal? By using the storage mode I can make
it easily viewable, and stay on the screen until the next sweep, I just
can't seem to make it reliably trigger. Ideas?
-Cliff
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If you've wondered why some TE have no fan:
<>
Start watching around 19:55 time.
Dave
|
Re: 466 Trigger on <1Hz Square Wave?
I have it set to normal mode, I've
tried both AC, DC, and HF reject couplings, and the channel itself
is coupled DC. But it still seems to only want to trigger on the
little bit of ripple on the wave, and not actually the signal
itself.
On 03/02/2013 12:12 AM, David wrote:
toggle quoted message
Show quoted text
You can absolutely trigger on low frequency signals including slow
ramps. Be sure to set TRIG MODE (below the time/div control on the
right side) to NORM instead of AUTO to prevent the sweep from free
running when the triggers occur slower than about 20 Hz.
You may need to use DC input coupling and DC trigger coupling.
On Fri, 01 Mar 2013 22:12:46 -0600, Cliff White
wrote:
I have a case where I need to use my 466 to view a /very/ slow (less
than one Hertz) 5 volt p-p square wave. Is it possible and/or easy to
make it trigger on such a signal? By using the storage mode I can make
it easily viewable, and stay on the screen until the next sweep, I just
can't seem to make it reliably trigger. Ideas?
-Cliff
------------------------------------
Yahoo! Groups Links
<*> To visit your group on the web, go to:
<*> Your email settings:
Individual Email | Traditional
<*> To change settings online go to:
(Yahoo! ID required)
<*> To change settings via email:
TekScopes-digest@...
TekScopes-fullfeatured@...
<*> To unsubscribe from this group, send an email to:
TekScopes-unsubscribe@...
<*> Your use of Yahoo! Groups is subject to:
|
Re: Could please any one give a clue about this nice pulsed line generator??
I would have used different connectors just to prevent getting the output and the charge line mixed up. On Sat, 02 Mar 2013 18:03:07 -0000, "iglesia_cristiana_arpas_eternas" <iglesia_cristiana_arpas_eternas@...> wrote: Yes David I agree , I just wonder me why BNC was a good choice for output pulse, but not for transmission line extender, since both are on the same power and rise time stress...???
Gabriel.
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David Hess
ROLYNN PRECHTL K7DFW