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---- Dave_s <group78@...> wrote:

TekScopes@... wrote:

Re: 7603 filter caps

FWIW I have built the
<> esr meter and can recommend it
but keep in mind that it will show a very low ESR on a shorted cap : )

Hi,

I am trying to see that ESR Meter circuit referred to in this
mailnote. I'm very interested in building this circuit. Please help me
by providing a usable URL. On this site, searching for ESR produces no hits.

Thank you. 73, W6MIK, Dave

Very sorry, try this

If you have a few spare parts, you can build a capacitor ESR meter
quite easily. Below is a prototype I built. I just added the spice model
to the web page in case you want to explore how it operates.
cheers



--

=====================================================================
Lawrence Glaister VE7IT mailto:ve7it@...
1462 Madrona Drive
Nanoose Bay, B.C.
Canada V9P 9C9
=====================================================================

Dave -

Try here.

<>

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 4-B, C-Line & TR-4/C Service Supplement CDs
<www.k4oah.com>



Dave_s wrote:

I've got one of these:-
very good it is, too.

www.peakelec.co.uk/acatalog/jz_esr60.html

TekScopes@... wrote:

Re: 7603 filter caps

FWIW I have built the
<> esr meter and can recommend it
but keep in mind that it will show a very low ESR on a shorted cap : )

Hi,

I am trying to see that ESR Meter circuit referred to in this
mailnote. I'm very interested in building this circuit. Please help me by providing a usable URL. On this site, searching for ESR produces no hits.

Thank you. 73, W6MIK, Dave

Or use this software:



Which now also includes the option of downloading the entire 2500 record
(worth 10 divisions in height) and plot it on the screen (I need to upload
that version, later today).

Didier KO4BB

I hope this goes thru ok and helps some people ...



TDS Screen Capture

via the RS-232 option









This screen image was captured from a TDS oscilloscope over the RS-232 port using the Windows Hyperterminal program. To transfer the screen image follow the procedure outlined below.



1. Start Hyperterminal

2. From the TDS Utility IO menu set the port to RS-232.

Harware Setup: 9600,1,none,on.

Software Setup: Soft Flagging Off.



3. Set the hard copy format. ( This image was produced using PCX )



4. Set the communications settings in Hyperterminal to match those of the oscilloscope. 9600,8,1,None, Hardware.



5. In the Hyperterminal program, select File Properties click on the settings tab. Click on the ASCII Setup button and un-select Wrap lines that exceed terminal width. This will enable the Hyperterminal program to save binary screen images.



6. Go to Transfer menu, Capture Text, and select a file name and location.



7. Once you have the image you want on the oscilloscope display, press the HARD COPY button.

Hi All,
I hve been a member of this list for some years now but not done much in the
way of posting.
I am having to part out a large number of scopes damaged about 10 years ago
so I am asking advice on what I should salvage from them? obvious parts like
the tubes and CRT's plus power transformers I am removing but should I keep
anything else like delay lines etc., I might add that knobs and front panels
are damaged due to rusted grub screws and the effect of salt water on the
aluminium parts.

Some of the types are, 316, 317, 506, 561, 564, 565, 524, 549, 545A, 545B,
551, 555, 556, 543, 541, 945, 561R, plus more and there a couple of each in
some cases.

In addition I will continue to try and refurbish some like a 310A, 575, and
a 535 which have sentimental value.
I hate to have to do this, but I am running out of time to rebuild much more
as I am now strugeling with health issues and on a pension. I have to
reduce the pile to a more manageable amount as there is radio equipment as
well, so storage cost's are now a premium.

Chris Gill
VK4YCG.

----------


----------


No virus found in this outgoing message.
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Greetings,
?
Very good point. For high impedence gear, the ESR most likely is too low to be a factor.
?
Jerry

This seller has a few expensive items, all of the bid up buy the same
buyer. Seems suspicious to me.

Neil

I've been watching auctions for 7D15s for a while because I have few I'd like to sell. The closing prices (not including shipping) have been around $10-$25, with some not selling for even less. Some of these are known good with a return policy. (I'd like to get $65 each for mine)

Suddenly, I find 370090549165, which has past $100. It's not been tested, and has nothing particularly interesting about it except that it looks new.

What about this item is generating the bids? The fact that it's in Canada?

-Dave

exception of the 7854, 7612 and 11xxx series with require -10.

Craig
--------

Which is a -02 with only a minor mod.
/H???kan

Absolutely - and can be retrofitted if necessary on a bit of bodge board.

Craig

--- In TekScopes@..., "Craig Sawyers" <c.sawyers@...> wrote:

An -02 will work perfectly with any Tek scope up to 1GHz B/W. With

the

exception of the 7854, 7612 and 11xxx series with require -10.

Craig
--------

Which is a -02 with only a minor mod.
/H?kan

Does the -02 work for slower scopes like the 7704A? If I bought one I
might as well get one that can do as many scopes as possible.

An -02 will work perfectly with any Tek scope up to 1GHz B/W. With the
exception of the 7854, 7612 and 11xxx series with require -10.

Craig

The ESR is critical to ripple.

Like all these things, the devil is in the detail. Lets assume that we are
talking about a smoothing capacitor conventional 50/60Hz system, and not a
switcher.

Provided the ESR is significantly less than the total driving impedance (Tx
secondary, reflected primary, diode R etc) there is no significant effect.
Here are some numbers for a supply with a 220uF capacitor fed by 1N4007
diodes from a 333V secondary with a total series resistance of 31 ohms
(typical for valved/tubed applications in classic Tek gear). The current
draw is 100mA.

ESR ripple p-p
0.1 3.7V
1 3.9V
3 4.8V
10 8.9V

So in order to double the p-p ripple you need to have an ESR that is about
30% of the total series resistance feeding it. *For this particular
example*. Note that the waveform becomes much more "spikey" at higher ESR,
and hence the RMS value is much less effected.

Craig

Thanks all for the discussion.
I have ordered new caps as well as an ESR meter. I expect the new caps will help, but am also curious as to the condition of the old ones.
By the way, the comment about using several smaller caps in parallel helps explain why the TV I am working on has two 10,000uf in parallel.
Bob

---- Bernice Loui <rupunzels_window@...> wrote:

Hello,

It's also dependent on frequency.. If the 'lytic cap in question is used in a good old fashioned line frequency copper/iron power transformer, the ESR requirement is not very high since ripple frequency for a full wave rectifier is 120 Hz in the US and 100 Hz in other parts of the world. Most any garden variety cap should be good for this.

Not true for high frequency switching power supply capacitors. As the Equivalent Series Resistance goes up, the losses per cycle goes up too which causes internal heating inside the capacitor and shortens it's life. This is why capacitors have a ripple current rating on top of the ESR spec.

Many of the current generation low ERS capacitors are designed for use in switching power supplies and one look should examine the ESR vs Frequency curve to decide if this part will work for it's intended application. Ripple current vs frequency is another consideration along with max temperature which is usually +85 or +125 degrees C. There is also a life rating in hours based on temperature and ripple current.

Be aware that while the new generation of smaller 'lytics pack a lot of capacitance and performance in a small package, they can be short lived. Hour ratings of 2,000 hours at it rated ripple current and temperature. Expected capacitor life is quite dependent on operating temperature and circuit conditions. They are a wear out part in just about every electronic device :(


Bernice


~~~~~~~~~~~~~~~~~~~~~~~~~
--- On Thu, 10/2/08, Jerry Massengale <jmassen418@...> wrote:

The ESR is critical to ripple.

Case in point / preaching to the choir.
You often see cases where, for example, instead of using one 500 MFD capacitor the designer
has elected to use five 100 MFD capacitors in parallel.
This is often seen on PC MBs for example.
The use of multiple caps in parallel lowers the esr and the lead inductance as compared to a smaller
number of larger caps and this lowers the temperature and ripple and, as implied above, will increase the service life

FWIW I have built the esr meter and can recommend it
but keep in mind that it will show a very low ESR on a shorted cap : )

Actual capacity and leakage at the working voltage a important also.
Bert

I need a couple of spring hook tips for a P6109 probe. Does anyone have any
to spare?

David
KC2JD/4

The 067-0587-02 (or -10) version is good far ANY 7000 series 'scope. The
-10 version is also good for 113xx and 114xx 'scopes as well (I think).

Dave

Hello,

It's also dependent on frequency.. If the 'lytic cap in question is used in a good old fashioned line frequency copper/iron power transformer, the ESR requirement is not very high since ripple frequency for a full wave rectifier is 120 Hz in the US and 100 Hz in other parts of the world. Most any garden variety cap should be good for this.

Not true for high frequency switching power supply capacitors. As the Equivalent Series Resistance goes up, the losses per cycle goes up too which causes internal heating inside the capacitor and shortens it's life. This is why capacitors have a ripple current rating on top of the ESR spec.

Many of the current generation low ERS capacitors are designed for use in switching power supplies and one look should examine the ESR vs Frequency curve to decide if this part will work for it's intended application. Ripple current vs frequency is another consideration along with max temperature which is usually +85 or +125 degrees C. There is also a life rating in hours based on temperature and ripple current.

Be aware that while the new generation of smaller 'lytics pack a lot of capacitance and performance in a small package, they can be short lived. Hour ratings of 2,000 hours at it rated ripple current and temperature. Expected capacitor life is quite dependent on operating temperature and circuit conditions. They are a wear out part in just about every electronic device :(


Bernice


~~~~~~~~~~~~~~~~~~~~~~~~~