Re: Making a Q-meter /
Could you please sketch it out, as I am not following it. Dave
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Dr. David Kirkby, Kirkby Microwave Ltd
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#43
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Re: Making a Q-meter /
You raise the issue here of how to generate a signal with very low source resistance. How about this idea. Consider a signal source feeding a resistive divider consisting of Rs (source) and Rl
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Navmar
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#42
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Re: Making a Q-meter /
Well Jeffrey, you bring up an interesting point. I bought a 160-A from the USA a few days ago. https://www.ebay.com/itm/185508135243 The shipping was a *suspiciously *low $21.72. It's going via the
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Dr. David Kirkby, Kirkby Microwave Ltd
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#41
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Re: Making a Q-meter /
wrote: Do you know of a model number(s)? My search with Google didn¡¯t bring up anything useful. There are plenty of LCR meters, but unless significantly different from my 4284A and 4285A, they are
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Dr. David Kirkby, Kirkby Microwave Ltd
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#40
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Re: Making a Q-meter /
[email protected]> wrote: Thank you. That is the best 260-A manual I have seen, although I have seen a ¡°manual¡± that covered a few of the Boonton models. I always felt that there should be one
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Dr. David Kirkby, Kirkby Microwave Ltd
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#39
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Re: Making a Q-meter /
I have a real Boonton Q meter.? Yes it was made with tubes (valves).? But it was a truly outstanding meter in its day.? David, I would consider giving it to you for trade for something else small
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Jeffrey Pawlan
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#38
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Re: clock calibrator
Oops again. I meant 74HC4059 (/10000 capable), not 74HC40102(/100 capable). Also note that the Kb control inputs on the counters can be used with a small amount of logic to initialize the counters for
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SCMenasian
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#37
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Re: Making a Q-meter /
On? Thu, 4 Aug 2022 9:19? Dr. David Kirkby wrote: "A step-down transformer seems the most obvious way...? I have not yet looked at the HP 4343A meter service manual. That will probably give me some
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[email protected]
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#36
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Re: Making a Q-meter /
wrote:
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Dr. David Kirkby, Kirkby Microwave Ltd
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#35
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Re: Making a Q-meter /
Have a look at the manual of the Rhode & Schwartz? QMeter
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jfphp
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#34
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Re: Making a Q-meter /
If you have not already done so, you may want to read through the Boonton 260 Q Meter manual. It is a wealth of information and provides a lot of insight on where errors creep into measurements. The
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Chuck Moore
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#33
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Re: clock calibrator
Oops, It's too early in the morning - Upon proofreading of my posted message, I find that I have mistakenly substituted 10 Hz for 0.1Hz throughout. Sorry, Stephen Menasian
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SCMenasian
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#32
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Re: clock calibrator
Since I don;t have a VNA and constructing one in less than a couple of months is a major undertaking, I would probably take the following approach, using components in my junk box. 1) Construct 2
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SCMenasian
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#31
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Re: clock calibrator
Since I don't have a VNA and constructing one would take more htan a couple of weeks, I'd probably take the following approach using components in my current inventory: 1
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SCMenasian
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#30
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Re: Making a Q-meter /
I think the best method for measuring loaded and unloaded Q and at the same time the coupling factor is by using the resonance circle that is created on the smith chart of VNA. Read the article by
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amirb
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#29
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Re: Making a Q-meter /
On Thu, Aug 4, 2022 at 02:14 AM, Kenneth Greenough wrote: > > Re' a Q meter. > This is only a thought idea, not tested hi. > Have a small enclosure with sockets on opposite sides. each socket has a >
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Dr. David Kirkby, Kirkby Microwave Ltd
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#28
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Re: Making a Q-meter /
I see another problem that I was unaware of. There are two definitions of Q I am aware of 1) Q = 2 P Energy_stored_per_cycle / Energy _dissipated_per_cycle 2) Q = fr (f2 - f1) where fr is the resonant
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Dr. David Kirkby, Kirkby Microwave Ltd
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#27
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Re: Making a Q-meter /
Re' a Q meter. This is only a thought idea, not tested hi. Have a small enclosure with sockets on opposite sides. each socket has a single turn loop attached with sufficient distance between the two
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Kenneth Greenough
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#26
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Making a Q-meter /
I am looking at the possibility of making a Q meter for the frequency range 1.5 MHz to 150 MHz. One common way to do this is to inject a voltage from a LOW impedance source, into a series tuned
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Dr. David Kirkby, Kirkby Microwave Ltd
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#25
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Re: clock calibrator
This is the method used for the VNWA frequency meter. Also for generation Allan deviations on the fly. Kind regards Kurt Fra: [email protected]
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Kurt Poulsen
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#24
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