Thanks, all-

"You'll know it when you see it." <grin>.

In a way, that makes me feel better - thought I was missing something very obvious.? Thing is, the jitter - as a percentage of current frequency -? varies with frequency as well as voltage; that is to be expected of course but it left me trying to decide if a percentage that I would be unhappy with at 1 MHz was OK for .01 Hz. The required spec is 25 mV RMS and so far all have (to me) been reliable to around 10-15 mV at <10 Hz and the stability improves rapidly at higher frequencies so I'm going to call it good.

Thank you again for taking the time to answer,

Hal

@Don Bitters:

I'm not sure what you mean by the Uwave port. There are two RF input ports on the HP11729C, the 5-1280MHz port (used, in the phase detector configuration for the Reference Oscillator) and the Microwave Test Signal input port (used to connect the DUT - by Uwave are you using a "U" to represent Micro?). The Reference Oscillator is a Wenzel HF-ONYX-IV, which has an EFC pin allowing the fundamental frequency to vary between 10 MHz +/- 10 Hz. For the simple input power test I described, I used the Reference Oscillator with its signal running through a directional coupler and adjustable attenuation pad (adjustable in units of 1 dB). I haven't checked the Reference Oscillator signal for harmonics or purity, but it is a new unit and has pretty good harmonic specs < -30 dB (see . Phase noise is ultra-low for this device (e.g. 10Hz <= -136 dBc/Hz). My Rigol (1104Z) is an entry level unit without a phase noise measurement app.

I think John Miles has figured out the discrepancy between the recommended input level (7-18 dBm) and the statement that the mixer compression point is 3 dB. The first seems to reference the input level when using the downconverter hardware, which as you point out is not used for a 10 MHz signal. The second is the compression point on the phase detection mixer (not the Microwave downconverter mixer - ?see figure 4.4 on page 21 of?).

@Leo Bodnar:

I don't, as yet, have any phase noise plots, since I am trying to figure out the proper test setup procedure (including input power levels).

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I'm not an RF/microwave type, although I do a lot of building and experimenting.? RF is a whole 'nother world when looking at digital, programming, and microprocessors.? I do have sufficient stuff for that, though.? The fields start to overlap if the digital is fast enough, depending on the transmission medium.

For the LCR meters, I have a 4262A which works well for my needs.

Harvey

Not even any offers…? not many builders/experimenters remaining out there I guess.?

>
>
> Still have the following available… all tested and working properly.? Pics on request.
>
>
>? ? ?4284a? lcr(z) $1650. Into storage trailer this week
>
>? ? ?4285a? lcr(z) $1650. Into storage trailer this week
>
>? ? ?83712b. 20GHz sig. gen, $1800… offers??
>
>? ? ?sold
>
>
>? ? ?sold
>
>? ? ?8720d 20GHz VNA. $6150… offers ?
>
>? ? ?8562a 22GHz spec an, $1250… into trailer this week
>
>? ? ?All tested and working fine. Once into trailer… next of kins' problem

>
>? ? ?Thanks for looking,
>? ? ?Pete wa2odo?

Have you checked the disk for dirt, damage, etc.? I also had an issue with a BluRay disk player, with a similar shutdown issue - there was a tiny smudge on the disk at about the right spot, but it did not clear the problem. Power down did not cure it, but disconnect, and power up did solve it. The modern PCs, TVs, and players are not really off when powered down - just in sleep mode, so all of the previous states are remembered. Try disconnecting power for about 5-10 minutes.
Don Bitters

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Sent from K5JLR

At 2019-07-28 12:18 PM, ken chalfant wrote:

We have a nice little Sony model DVP-NS300 DVD player.? It works great with one unusual affliction.

Sometimes while playing a DVD the player powers off.? When we turn it back on and continue to watch the same DVD, whether from the beginning or near where we were when the unit powered off when it gets to EXACTLY the same place on the DVD and same number on the counter it powers off again.

I don't have an answer for you, but it's certainly an interesting problem, and likely the right group to answer it. Could it have something to do with Digital Rights Management? Maybe the DVD thinks it's a pirated copy, and the player just allows it to play for a short time before shutting down?

Steve Hendrix

Hello Ken,

I don't know much about DVD players, but that sounds more like a crash than anything else. If the data at that particular timestamp triggers an error in the decoding software or hardware, then two things can happen that can generate this behaviour:

1) Some controller freezes and then a watchdog system kicks in and cuts the power.
2) The device is made so an exception like the one I described is handled with a shut down.

Again, I don't know much about DVDs, so if you're right and there is an instruction to turn them off, then you can add that to the list as well.

Razvan

--
Razvan Cojocariu
Cojotech SRL

+4073 558 3392

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Greetings,

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Hal, I take that to mean when the frequency display starts to deviate quickly and significantly from the stable frequency it was showing with the higher input signal. In "layman's" terms, the counter becomes "unglued" and instead of a single stable frequency you will see one frequency one count and an entirely different frequency the next count and yet a different frequency the next count, etc, etc.

Gedas, W8BYA

Gallery at 
Light travels faster than sound....
This is why some people appear bright until you hear them speak.

You'll know it when you see it. The way I understand that is that you have to lower the input signal's level until it starts displaying the wrong frequency (it will start triggering on noise and the reading will jump around).

But I understand why you're asking... if it's not specified anywhere, then who decides how many counts out is considered unstable?

Cheers,
Razvan

--
Razvan Cojocariu
Cojotech SRL

+4073 558 3392

All-

I'm currently testing a few 5335A counters, and on the Frequency Response and Sensitivity Test portion of the Performance Tests it directs you to adjust the signal level until "...the 5335A gives an unstable count..."? Nowhere that I can find is there a definition of exactly what qualifies as unstable.? I'm tired and I know that I must be missing something obvious, but I would truly appreciate anyone giving me input on this.

TIA,

Hal

What do your phase noise plots look like at different settings??

Unless your DUT is injection-locking to the the reference the best noise plot is probably the best input level setting.

Highly corrupted signal will also stop most systems calculating reasonable detector constant - which they will inform you about.

Leo

Barry,

There might be a slight misunderstanding over what I said about the resistor on the filament line.? From what I can see it is present in both manual schematics I cited.? If it does affect the filament supply voltage I am wondering if HP anticipated possible mixing of probes from the pre-C versions of the 410 to the C version.? Unfortunately the data sheets for both the EA53 & 2-01C only state the filament operating voltage and not any operating current so without taking actual voltage measurements it is difficult to determine if HP is utilizing the current limiting characteristics of the transformer winding.

I have used the 11729C extensively as part of a 3048C phase noise test system. ?There are internal attenuators to limit the input level. ?If I recall correctly The nominal level for an RF signal is +3dBm. ?Are you using the RF port or the Uwave port for your input? ?What are you using as your reference signal? ?To what level are you checking for harmonics and purity? ?You won’t be using the downconverter portion of the 11729C at all with crystal oven checks. ?So you will be bypassing the filtering and Uwave down converter assy., but using the low frequency downconverter to look at the phase noise and harmonics - signals that are in the limits of your Rigol. Does your Rigol have a phase noise measurement app.?
Don Bitters

Thanks John.

For clarification, I am using the 1Hz - 1MHz noise spectrum output of the HP11729C. This bypasses the LNA and filters the signal through a 1.5 MHz LPF. See figure 4.4 on page 21 of?

Dan

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Okay - that makes more sense.

Thanks,
Barry - N4BUQ