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Isn't the 1345A the smaller ~5" version used in eg. 3577VNA? Ulf SM6GXV

When discussing P-Touch labels, bear in mind that M-type machines are a thermal ink process and TZ-type machines use a thermal transfer process that is self-laminating. M-type is substantially more

Hi Group, My E4407B has the problem of 'LO unlock'. I am in the process of repairing the unit by replacing a frequency divider. I am following the youtube video in the SignalPath channel. Before

Hi Harke, thanks! It's interesting to see the return loss plot of the 8478B sensor out to 3 GHz. I've started a thread about the input return loss of the 478A sensors and how they have changed

The other thing to bear in mind is that the latest 478A service manual clearly shows that all versions of the standard 478A sensor (note that this doesn't include H7x options) can be used with both

Just to keep things in perspective, the input VSWR will be a function of the design of the 478A sensor and will also be affected by the performance of the 432A power meter to some degree. However, if

Philip, I thank you for the information; yes it may be that we were typing at the same time! I shall look further this morning and see what I find.

That's actually Front Panel Express ( https://www.frontpanelexpress.com/ ) , and I think they're great - I use them quite a bit.? They have their own specialty CAD package to design a front panel,

Thanks for all the info! Unfortunately, none of those schematics match the layout in my instrument. For example, the PCB I have has no C20 (connected to pins 2 and 3 of U4), or any provision for C20

In case any purists want to scoff at this matching technique and think it is a bodge, I suggest they take a look inside a typical HP power meter and look at how the 1mW oscillator is designed and how

On Sat, 17 May 2025, jmr via groups.io wrote: There are separate manuals for all those Hxx 478A sensors. There was a whole bunch of those, all seem to be nearly identical according to their manuals.

Here's a screenshot from my old Agilent VNA showing the input VSWR of my 478A sensor with the matching section added at the input. You can see that it now achieves a really low VSWR at 50 MHz. Because

On Sat, 17 May 2025, jmr via groups.io wrote: H72 is SPECIFICALLY designed for low frequency measurements, especially that 50MHz one. It is not high frequency device going into gigahertz range so it

Just to clarify, the latest service manual for the standard 478A sensor is available on the Keysight website and this lists the different internal circuits for the early and later variants of the

OK thanks. I think the standard 478A sensor uses a tiny (and very thin) SMD disc cap of about 1350pF for the AC ground end of the thermistor. The later 478A sensor uses 1200pF here.? I don't know

Hi Joe, If you just change some parts without knowing why you only make it worse. You give exact 0 information what was your error-picture, what you did or what voltages did you measure. My advice:

On Sat, 17 May 2025, jmr via groups.io wrote: There are 0.1uF C0G capacitors in 1206, nothing special. I have a reel of those and use them often. Dunno what capacitors are inside H72 probe although I

Here's an image showing the completed matching adaptor that contains the series 11nH inductor. This is constructed using two precision N bulkhead connectors, one male and one female. I salvaged them

For C14 & C20 the can has several tabs that secure them to the board - these are common with the "-" of the capacitor and the can itself is often used to complete the circuit.? Make sure that all of

I'd expect the 0.1uF caps in the H72 sensor to be class 2 ceramic types as it's hard to imagine COG/NP0 being used here. This would presumably make the reactance at 10kHz susceptible to temperature